2525.01 GENERAL.

A. Description.
The work to be performed under this specification shall consist of furnishing all work, apparatus, and materials to construct, install, and place in operation, a complete traffic signal system as shown in the contract documents. The Contractor shall furnish and install all components of the system not furnished by the utility company serving the traffic signal system, including all incidental items appurtenant to the operation of the system.

B. Equipment and Materials.
Equipment and materials shall be of new stock unless the contract provides for the relocation or the use of fixtures furnished by others.

The Contractor shall submit to the Engineer, for review, a list of equipment and materials to be furnished before they are ordered. The Contractor shall replace at no additional cost to the Contracting Authority, any part that fails in any manner by reason of defective materials within a period of 1 year from the date that the equipment was placed in operation and accepted. The Contractor shall provide the standard industry warranties for all equipment at the date of final acceptance of the work by the Engineer.

Shop drawings will be required for the poles and mast arms, and these shall be submitted in accordance with Article 1105.03.

Before acceptance of the work, the Contractor shall furnish the Engineer with five copies of the manufacturer's instructions for maintenance and operation of all signal equipment, wiring diagrams of the installation or system and a parts list sufficient for the ordering of any parts.

1. Handholes.
Handholes shall be either built in place or shall be a precast unit. When forms are used, they shall be set level and of sufficient thickness to prevent warping or other deflections from the specified pattern. A means shall be provided for holding them rigidly in place while the concrete is being placed. The ends of all conduit leading into the handhole shall fit approximately 2 inches (50 mm) beyond the inside wall. A drain shall be constructed in the bottom of the handhole. Frames and covers for handholes shall be made of cast iron. Handhole covers shall have the words "TRAFFIC SIGNAL" cast on the top of the cover. They shall be set flush with the sidewalk or pavement surface. When installed in an earth shoulder away from the pavement edge, the top surface of the handhole shall be approximately 1 inch (25 mm) above the surface of ground. When constructed in unpaved driveways, the top surface of the handhole shall be approximately level with the surface of the driveway. Concrete shall meet requirements of Section 2403.

2. Concrete Bases for Poles.
The material for the forms shall be of sufficient thickness to prevent warping or other deflections from the specified pattern. The forms shall be set level, and means shall be provided for holding them rigidly in place while the concrete is being deposited. All conduit, ground rods, and anchor rods shall be installed rigidly in place before concrete is deposited in the forms. Placement of anchor bolts shall be in accordance with Article 2405.09, B. Anchor bolts for the signal poles shall be set in place by means of a template constructed to space the anchor bolts in accordance with the manufacturer's requirements. The center of the template and the center of the concrete base shall coincide. Concrete shall meet requirements of Section 2403. The top of the base shall be finished level and the top edges shall be rounded with an edger having a radius of 0.5 inch (13 mm). The top of pole bases shall be set flush with the sidewalk or pavement surface. When installed in an earth shoulder away from the pavement edge, the top of the concrete base shall be approximately 4 inches (100 mm) above the surface of the ground. The exposed surface of the base shall have a wood floated finish.

3. Conduit System.

a. Installation.
Change in direction of ducts shall be accomplished by bending the conduit uniformly to a radius which will fit the location (minimum radius 6 times the internal diameter of the conduit), or by the use of standard bends or elbows. When it is necessary to cut and thread steel conduit, no exposed threads will be permitted. All ducts and fittings shall be free from burrs and rough edges. Standard manufactured elbows, nipples, tees, reducers, bends, couplings, unions, etc. of the same materials and treatment as the straight duct shall be used throughout the duct system. All fittings shall be tightly connected to the duct. All duct ends shall be provided with a bushing to protect the cable from abrasion, except for open ends of conduit being placed for future use which shall be capped or plugged.

When the contract documents require that ducts be placed without disturbing the existing pavement, the term "pushed" is used. "Pushed" conduit shall be placed by jacking, pushing, boring, or any other means necessary to place the ducts without cutting or removing pavement.

All ducts shall be sloped to drain and shall be provided with crushed stone drainage sumps at all handhole locations.

b. Excavation.
Trenches shall be excavated to a depth as necessary to provide 18 inch (0.5 m) of cover over the ducts. All cinders, broken concrete, or other hard or abrasive materials shall be removed and shall not be used in backfilling. The trench shall be free of these materials before the conduit is placed. No ducts shall be placed prior to inspection of the trench by the Engineer. All trenches shall be backfilled as soon as possible after installation of ducts. Backfill material shall be deposited in the trench in layers not to exceed 6 inches (150 mm) in depth and each layer shall be thoroughly compacted before the next layer is placed. Whenever excavation is made across parkways, driveways, or sodded areas, the sod, topsoil, crushed stone, and gravel shall be replaced or restored as nearly as possible in its original position, and the whole area involved shall be left in a neat and presentable condition. Concrete sidewalks, pavements, base courses, and bituminous surfaces shall be replaced with new materials.

4. Wire and Cable.
All cable runs shall be continuous from connections made in the handhole compartments of signal pole bases to the terminal compartment in the controller cabinet. Splicing will not be allowed. The Contractor shall install one signal cable from each signal head to the base of the pole. A 5-conductor cable shall be utilized in the poles for 2-section, 3-section, or 4-section signal heads and a 7-conductor cable shall be utilized for 5-section signal heads.

Service cable runs shall be continuous from the service point to the terminal compartment on the controller cabinet. Loop detectors shall be connected to the controller by a 14 A.W.G. 2-conductor shielded cable. These cables shall be continuous from the terminal compartment in the controller cabinet to a splice made with the detector leads in the first handhole or pole base junction box provided adjacent to the detector.

Cables shall be pulled through conduit by means of a cable grip designed to provide a firm hold upon the exterior covering of the cable or cables, with a minimum of dragging on the ground or pavement. This shall be accomplished by means of reels mounted on jacks or other suitable devices. Frame mounted pulleys or other suitable devices shall be used for pulling the cable out of conduit into handholes. Only lubricants which are approved for cable lubrication shall be used to facilitate the pulling of cable. Slack for each cable shall be provided by a 4 foot (1.2 m) loop in each handhole.

a. Power Cable.
Power cable shall comply with Article 4185.12 and shall be UL listed for type "USE".

b. Signal Cable.
Signal cable shall meet the requirements of IMSA Nos. 19-1 or 20-1.

c. Loop Detector Wire.
Loop detector wire shall be a single conductor meeting standard requirements for THHN. Loop detector wire shall be meet the requirements of IMSA No. 51-5.

d. Detector Lead-In Cable.
Detector lead-in cable shall meet the requirements of the IMSA No. 50-2.

e. Tracer Wire.
Tracer wire shall be single conductor, stranded copper, Type THHN, with UL approval and orange colored jacket.

The tracer wire shall be spliced in the handholes, cabinet, and pole bases to form a continuous network.

f. Communications Cable (Conductive).
The cable shall meet the requirements of the IMSA No. 39-2 or 40-2.

g. Bare Copper Ground Wire.
The ground wire shall meet the requirements of Article 4185.12.

5. Detector Loops.

a. Installation.
The detector loop wire shall be inserted into a flexible plastic tubing for the full length of the wire from the point of splicing. The field loop conductors installed in the pavement shall run continuously from the terminating service box or base with no splices permitted. At the time of placing the loop wire in the sawed slots, the ends of the tubing shall be sealed to prevent moisture from entering the tubing.

All lengths of loop wires and tubing that are not imbedded in the pavement shall be twisted with at least 5 turns per foot (16 turns per meter), including lengths in conduit and service boxes.

The electrical splice between the loop and lead-in cable to the controller and the loop wire shall be soldered using resin core solder and provided with a water tight protective covering for the spliced wire, the shielding on the loop lead-ins and the end of the tubing containing the loop wires. The use of open flame to heat the wire connection will not be permitted. The Contractor shall use a soldering iron, gun, or torch equipped with a soldering tip. The splice shall be made by the following method:

1. Remove all lead-in cable coverings leaving 4 inches (100 mm) of insulated wire exposed.

2. Remove the insulation from each conductor of a pair of lead-in cable conductors and scrape both copper conductors with knife until bright.

3. Remove the plastic tubing from the loop wires for 1.5 inches (40 mm).

4. Remove the insulation from the loop wires and scrape both copper conductors with knife until bright.

5. The conductors shall be connected by a soldered "Western Union" type splice, wrapped with water proof tape and coated with a water tight protective covering.

6. Cover the exposed shielding, ground wire and end of any unused loop lead-in where the sheathing was cut, with liquid silicone rubber. Apply Butyl Rubber Polymer Tape sealant between the wires and completely cover the silicone rubber. As an acceptable alternate, the Contractor may use a 3M Company Scotchcast Kit, or approved equal, for splices.

The location of each loop shall be marked on the pavement with crayon or spray paint. The Contractor shall obtain the approval of the Engineer prior to cutting the saw slots.

The saw shall be equipped with a depth gauge and horizontal guide to assure proper depth and alignment of the slot. The blade used for the saw cut shall provide a clean, straight, well defined 3/8 inch (10 mm) wide saw cut without damage to adjacent areas. The depth of the saw cut shall be 1.5 inches to 2 inches (40 mm to 50 mm) deep. Where the loop changes direction, the saw cuts shall be overlapped to provide full depth at all corners. Right angle or corners less than 90 degrees shall not be used.

Before installing the loop wire, the saw cuts shall be checked for the presence of jagged edges or protrusions. Should these exist, they must be removed. The slots must be cleaned and dried to remove cutting dust, grit, oil, moisture or other contaminants. Cleaning shall be achieved by flushing clean with a stream of water under pressure, and following this, the slots shall be cleared of water and dried using oil free compressed air.

Loop detector conductor shall be installed using a nominal 0.2 inch (5 mm) thick wood paddle. If the wire does not lay close to the bottom of the saw cut, it shall be held down by means of a material such as tape or doubled over pieces of the plastic tubing.

Each loop shall be coiled clockwise (or in accordance with manufacturer's recommendations) and the beginning conductor banded in the terminating handhole or base with a symbol "S" to denote start of conductor. Each loop shall be further identified by phase or function as shown in the contract documents, with durable tags.

Multiple loop configurations, spliced to a single lead-in loop, to be connected in series shall have the "S" conductor of the loop connected to the unbanded conductor of the adjacent loop.

b. Sealing.
After obtaining satisfactory test results, the loop shall be sealed with a flexible embedding sealer approved in Materials I.M. 491.18. The sealer shall be used in accordance with the manufacturer's instructions. The sealer shall be poured into the slot to half depth. When both the loop and lead-in slots are half filled, check for air bubbles and material pileup, and then proceed to fill the slots to roadway level. Excess sealant shall be removed by means of the "squeegee". In all cases, there shall be neither a trough or a mound formed. The sealer, when poured into a saw cut, should completely surround the wires, displace all air and completely fill the area of the slot, except for that portion filled with the wire hold down material. Allow sufficient time for the sealer to harden, in accordance with manufacturer's instructions, before allowing traffic to move over the area.

After completion of the sealing, the loop shall be tested individually at the handhole and as a group at the control cabinet. The completed sealed loop shall pass continuity, inductance, and resistance test prior to being accepted.

c. Loop Testing.
All loops shall be tested and documented by using the following procedures:

The insulation resistance of the loop wire shall be determined by the use of a "megger" with 500V applied to either loop wire to earth ground. The resistance shall be greater than 100 megohms.

The inductance of the loop will be determined by the use of a loop inductance meter.

d. Prefabricated Loops.
Prefabricated loops installed under new paving consist of loop wiring encased in a watertight plastic tubing assembly.

C. Testing of Signal Equipment.
After the project is open to traffic, the Contractor shall notify the Engineer in writing the date the signal or signal system will be ready for testing. Upon concurrence of the Engineer, the Contractor shall place the signal or signal system in operation for a consecutive 30 calendar day test period. If the signal is to operate independently of other signals or signal systems, it shall be tested as a single installation. If the signal is part of a system, the test period shall not be started until all signals in the system are ready to be tested. A system shall be tested as a unit. Any failure or malfunction of the equipment during the test period shall be corrected at no additional cost to the Contracting Authority. The Contractor will not be required to pay for energy consumed by the system, and working days will not be charged during this testing period.

The Contractor shall secure the services of an authorized factory representative of the controller manufacturer to check out the system and to make all necessary adjustments at the time the equipment is turned on in order to get all specified functions of the equipment working properly. The factory representative shall have on hand, at the time of the equipment turn on, the necessary tools, test equipment, spare modules, spare detector amplifiers, and other miscellaneous parts and equipment to check out the system and make all necessary adjustments. The Contractor shall also notify the Engineer 2 business days prior to turn on so the Engineer may be present at the turn on.

D. Certification of Equipment.
Certification from the manufacturers of all electrical equipment, signal supports, conduit, and cable shall be supplied by the Contractor stating the material complies with the specifications.

E. Documentation.
File documentation packages shall be provided with each signal system, which shall consist of the following:

1. Complete schematic diagram, accurate and current for units supplied.

2. Complete physical description of units.

3. Controller printout or equal documentation of initial controller settings installed in the field or in the office.

4. Complete installation procedure and performance specifications, both electrical and mechanical, for loop detector amplifier units.

5. Complete maintenance and trouble shooting procedures.

6. Standard industry warranties on units supplied.

7. Complete parts list identifying full names of vendors for parts not identified by universal part numbers such as JEDEC, RETMA, or EIA.

8. Pictorial of components layout on chassis or circuit board.

At least one full package shall be included in the controller cabinet and one full package given to the Engineer.

2525.02 Conduit.

A. General.
Conduit shall meet the requirements of Article 2523.10 and Article 4185.10.

B. Rigid Steel Conduit.
Conduit fittings shall conform to the requirements of ANSI C80.4.

C. Polyvinyl Chloride Conduit (PVC).
PVC shall be rigid PVC conduit meeting the requirements of NEMA TC-2, Type 2, and applicable UL Standards.

D. Innerduct.
Conduit referred to as innerduct conduit (IDC) shall be Schedule 40, high density polyethy6lene. Conduit shall provide nominal conduit size as indicated in the contract documents, be orange in color, and longitudinally ribbed on the inside wall. Conduit shall be purchased in continuous reel lengths to minimize splicing.

2525.03 CONTROLLERS, CABINETS AND ASSOCIATED EQUIPMENT.

A. General Design Requirements.

1. Purpose.
The purpose is to set forth minimum design and operating requirements for controllers, cabinet and associated equipment. Controller, cabinet and associated equipment shall conform to NEMA TS-1 except as modified by the contract documents.

2. Cabinet.

a. The controller unit and associated equipment shall be furnished completely housed in a cabinet of clean-cut design and appearance. The cabinet shall be constructed from 5052-H32 sheet aluminum alloy which has a nominal 0.12 inch (3 mm) thickness.

b. A hinged door shall be provided permitting complete access to the interior of the cabinet. When closed, the door shall fit the gasketing material, making the cabinet weather resisting and dust tight. The door shall be provided with a strong corbin #2 lock and key.

A small, hinged and gasketed door-in-door shall be included on the outside of the main controller door. The door-in-door shall not allow entrance to the controller mechanism or to exposed electrical terminals, but shall provide access to a small switch panel and compartment which contains a signal shutdown switch, manual/stop time, and a flash control switch. The door shall be equipped with a strong lock utilizing keys of a different design from those provided for the main cabinet.

3. Wiring.

a. The panel shall have mounted on it at least the following short circuit protection devices and suitably identified field terminals:

1) Terminals for the conductors of the signal light cable; one for each signal circuit.

2) Terminals for common return conductors of the signal light cable; at least one for each three signal circuits for which the controller is equipped.

3) Terminal, grounded to the cabinet, for an equipment grounding conductor.

The grounded side of the power service shall be carried throughout the controller in a continuous circuit but shall not be grounded to the controller cabinet.

b. The controller shall withstand without failure a high energy transient applied to the incoming power supply line. The transient shall be 1,000 volts, both positive and negative, applied three times for each polarity at a rate of once every two seconds from a 15 microfarad oil filled capacitor.

4. Contacts.
All contacts shall be of coin or fine silver or material of similar conductivity, shall be of sufficient cross section to perform their normal functions with minimum pitting or burning under maximum current, and shall not require fine adjustment and readjustment for satisfactory and continuous operation.

5. Mechanical Requirements.
All mechanism, motors, operating coils, bearings, contacts, relays, flashers, and similar components shall be sufficiently large, rugged, and accessible to insure reliability and minimum maintenance. All equipment shall be neatly and systematically arranged and mounted to allow thorough inspection while the controller is operating normally, and to permit easy removal components without interfering with other portions of the controller. Components shall be securely fastened in place, if necessary to prevent accidental contact with moving parts or electrical power and to permit the cabinet door to be opened and closed without interference or damage to the controller and wiring.

The opening and closing of the flashing circuit shall be accomplished in such manner as to avoid undue pitting or burning or other damage of signal load switches at 10 amperes of tungsten lamp load at 120 volts, 60 hertz AC, for 50 million times.

a. Each shall be equipped with additional terminals which are wired so that, by an interchange of jumpers, flashing operation may be arranged to display either flashing yellow or flashing red on each.

b. The cabinet shall be constructed so that flashing operation can be obtained by operating the flash control switch even if the controller unit malfunctions or is removed from the cabinet.

c. Each cabinet shall be equipped with adequate means to suppress or prevent radio interference from flashing of vehicular and pedestrian signal indications.

6. Uninterrupted Timing.
Any changes in operation of traffic control signal lights as described in Article 2525.03, A, 2, b, and Article 2525.03, A, 5, shall not interfere with the continued in-time operation of the cycle timer in each controller. A transfer from these special operations back to normal automatic operation shall immediately re-establish the normal cycle length and subsequently the in-time relation.

B. Preemption Features.
Controllers shall be equipped to provide special preemption sequences upon remote control from railroad track circuit, emergency vehicle preemption, mass transit equipment, or other similar device which may connect either through a master controller or directly to the interconnected controller.

C. Actuated Signal Controllers.

1. Description.
The controller unit shall be of completely solid state modular design. It shall incorporate digital timing and shall be capable of expanding to accommodate up to eight phases. Controller shall be NEMA TS-1 or TS-2.

2. Electrical Requirement.

a. Over-current Protection.
The controller shall contain a front-panel-mounted AC power input fuse of suitable size to provide adequate over-current protection.

b. Automatic Reorientation.
In the event of a power interruption the controller shall be capable of automatic reorientation upon power resumption and shall require no manual initiation or switching.

3. Constancy of Intervals: Minimum Requirements.
The length of any interval or timing setting shall not change by more than 100 milliseconds (±) so long as the voltage and frequency of the power supply and the ambient temperature inside the controller cabinet remain within the tolerances specified in these specifications.

4. Interval Sequence.
If, at the end of the green interval of the terminating phase, neither vehicle nor pedestrian memory indicates a need for the next traffic phase, the intervals which comprise that phase shall be omitted from the interval sequence.

This does not, preclude the use of recall which shall cause the phase to be displayed even though no detector actuations have been received.

5. Interval Setting and Functions.

a. Provision for Setting.
The control shall be calibrated in seconds and fractions of seconds, when applicable, and shall give a clear visual indication of the value of each interval or function. Setting of timing and function values shall be accomplished without the use of special tools or wiring changes.

b. Location of Controls.
The interval and function controls shall be located on the front of the controller and shall be properly designated as to the function each control performs.

c. Interval and function Indication.

1) Indication.
Indication shall be provided and appropriately labeled on the controller to facilitate the determination of operation and termination of the intervals and functions contained therein. Indication shall include but not necessarily be limited to the following:

Phase(s) next
Phase(s) in service
Status indicators
Initial interval
Vehicle interval
Yellow change interval
Maximum/gap termination

2) Call Indication.
Indication shall be provided on the controller to display presence of vehicle call, including memory and detector actuations and presence of a pedestrian call when pedestrian timing functions are included.

d. Vehicle Detector Non-Lock Memory Switch(es).
A switch shall be provided for each actuated vehicle phase which, when placed in the nonlock position, shall cause the vehicle detector memory circuit for that phase to be disabled.

6. Signal Circuits.

a. General.
The cabinet shall be provided with load switches, external to the controller, for closing and opening signal light circuits.

b. Closing and Opening of Circuits/Minimum Capacity.
The closing or opening of signal circuits shall be positive without objectionable dark intervals, flickering of lights or conflicting signal indications. Each switch shall have a capacity of not less than 10 amperes of incandescent lamp load at 120 volts AC.

c. NEMA Triple Signal Load Switch(es).
External jack-mounted load switches shall be provided in accordance with Part 5, "Solid-State Load Switches." Section TS-1-5.01, NEMA Traffic Control Systems Standards.

7. Conflict Monitor.
A separate, external signal monitoring device shall be provided to monitor the occurrence of conflicting Green or Walk indications and shall cause the signals to go into flashing operation should such conflicts be sensed. This shall conform to Part 6, NEMA TS-1.

a. Control of Flasher Mode.

1) Operation of flash mode from police panel shall not interrupt operation of controller and associated units.

2) An "auto-off-flash" mode switch shall be provided inside the cabinet.

b. Flashing of Vehicular Signals.
Flashing of vehicular signal indications shall be obtained from one or more flashers, each of which is a self-contained device designed to plug into a panel in the controller cabinet. If the flashing is provided by two flashers, they shall be wired to assure that the flashing of all lenses on the same approach is simultaneous.

c. Flashing of Pedestrian Signals (Pedestrian Clearance).
When pedestrian interval timing functions are included, means shall be provided to permit flashing of the DON'T WALK pedestrian signals during the pedestrian clearance interval.

d. Solid State Flasher.
A solid state flasher with no contact points or moving parts shall be provided. The solid state flasher shall be in accordance with Part 6, NEMA Traffic Control Systems Standards TS-1.

8. Manual Control Enable.
When specified, manual commands shall place vehicle calls and pedestrian calls (when pedestrian timing is included in the controller's sequence of operation) on all phases and stop controller timing in all intervals except vehicle clearances, and shall inhibit the operation of interval advance during vehicle clearances.

9. Coordination.

a. Minimum Requirements.
Means shall be provided within the controller to permit its interconnection into a coordinated traffic signal system when coordinating devices are added. As a minimum, this should include the provision of Yield circuit or Hold circuit, accessible to interruption by command external to the controller.

b. Coordination Requirements.
In addition to the minimum coordination requirements specified above, the controller shall contain the coordination features for the applicable configuration included in NEMA Traffic Control Systems Standard TS-1.

10. Cooling/Heating Devices.
No heating or cooling devices other than standard vent fan(s) shall be required for proper operation of the controller.

11. Cabinet.

a. Size.
The cabinet shall be of a size to adequately house the controller, all associated electrical devices and hardware, and other auxiliary equipment herein specified.

b. Mounting.
The cabinet shall be arranged and equipped for mounting as shown in the contract documents. Sufficient clamps, nuts, hardware, etc., as required for the specified mounting type, shall be furnished with each cabinet.

All conduit openings in the controller cabinet shall be sealed with sealing compound. this compound shall be readily workable soft plastic. It shall be workable at temperatures as low as 30°F (-1°C) and shall not melt or run at temperatures as high as 300°F (150°C). The controller cabinet shall be installed on preplaced caulking material on the concrete base. After the cabinet is installed in place, the Contractor shall also place caulking material around the base of the cabinet.

c. Door Stop.
The controller cabinet door shall be provided with a stop and catch arrangement to hold the door open at angles of both 90 degrees and 180 degrees, 10 degrees (±).

d. Mounting Shelves.
The cabinet shall contain strong mounting table(s) to accommodate the mounting of the controller and all auxiliary equipment. The mounting facilities shall permit the controller and/or auxiliary equipment to be withdrawn from the cabinet for inspection or maintenance without breaking any electrical connections or interrupting operation of the controller.

e. Mounting Screws.
Screws used for mounting shelves or other mounting purposes shall not protrude beyond the outside wall of the cabinet.

f. Outlet and Lamp.
An electrical outlet with a Ground Fault Interrupter and lamp receptacle shall be furnished and located in an accessible place near the front of the cabinet.

g. Plastic Envelope.
A heavy-duty clear plastic envelope, securely attached to the inside wall of the cabinet or cabinet door, shall be provided for stowing cabinet electrical prints, etc. Minimum dimensions shall be 12 inches by 18 inches (300 mm by 450 mm).

h. Ventilation.

1) Vents.
The cabinet shall contain a suitably designed rain tight vent or vents equipped with screens or filters. The vent(s) shall allow the release of excessive heat and/or any explosive gases which may enter the cabinet.

When filters are utilized, positive retainment shall be provided on all sides to prevent warpage and entry of foreign matter around the edges.

2) Vent Fan.
A thermostatically controlled vent fan shall be furnished to provide air circulation within the cabinet. The thermostat controlling the fan shall be manually adjustable to turn on between 90°F and 150°F (32°C and 66°C) with a differential of not more than 10°F (6°C) between automatic turn on and turn off.

The fan shall be located with respect to the vent holes to direct the bulk of the air flow over the controller and auxiliary equipment.

i. Connecting Cables, Wiring, and Panels.

1) Connecting Cables.
Electrical connections from the controller (and auxiliary devices when included) to outgoing and incoming circuits shall be made in a manner so that the controller (or auxiliary device) can be replaced with a similar unit, without the necessity of disconnecting and reconnecting the individual wires leading therefrom. This can be accomplished by means of a multiple plug, a spring connected mounting, or approved equivalent arrangement.

2) Panels and Wiring.
Each cabinet shall be furnished with suitable, easily accessible wiring panel(s). All panel wiring shall be neatly arranged and firm. All incoming cables shall be clearly identified by use of plastic numbered tags.

a) Wiring Terminals.
Terminals shall be provided, as a minimum, for the following:

Terminal with NEC approved cartridge fuse receptacle, fuse, power line switch, or magnetic circuit breaker, with integral power line switch, for the incoming power line.

Terminal, unfused, for the neutral side of the incoming power line.

Terminals and bases for signal load switches, flasher, and outgoing signal field circuits.

Terminals for detector cables.

Terminals for all required auxiliary equipment.

b) Clearance between Terminals.
Adequate electrical clearance shall be provided between terminals. The controller, auxiliary equipment, panel(s), terminals, and other accessories shall be arranged within the cabinet so that they will facilitate the entrance and connection of incoming conductors.

c) Signal Circuit Polarity.
The outgoing signal circuits shall be of the same polarity as the line side of the power service; the common return shall be of the same polarity as the grounded side of the power service.

d) Grounding Conductor Bus.
An equipment grounding conductor bus shall be provided in each cabinet. The bus shall be grounded to the cabinet in an approved manner.

j. Fusing and Surge Protection.

1) Incoming AC Line.
Suitable over-current protection, utilizing one of the methods described in Article 2525.03, C, 11, i, 2, a shall be provided.

2) Lightning.
Suitable protection from lightning will be provided with lightning arresters, preferably of the gas filter type.

k. Painting.
The aluminum exterior surface of the cabinet shall be unpainted.

D. Multi-Phase Traffic actuated Controllers.

1. Operational Requirements.

a. Mode of Operation.
The controller shall provide two to eight phase operation and shall be fully actuated with means for receiving actuations on all phases.

The controller shall also permit a nonactuated mode of operation on any of its phases by assertion of the vehicle recall function or pedestrian recall on the desired phase.

b. Call to Nonactuated Mode.
The controller shall feature an input which, when asserted, shall permit the selection of nonactuated mode of operation on any of its phases.

c. Operation with Auxiliary Functions/Devices.
The controller shall be capable of having its basic operation expanded or augmented by the addition of auxiliary functions or devices.

d. Minimum Green.

1) Actuated Phase.
The minimum green shall be the first timed portion of the green interval which is set in consideration of the storage of vehicles waiting between the sensing zone of the approach vehicle detector and the stop line.

2) Nonactuated Phase.
In the nonactuated mode of operation, the minimum green on the nonactuated phase shall be equal to the values described for Actuated Phases in the preceding paragraphs or shall be equal to a separately set Minimum Green function.

e. Unit Extension.
The actuation of a vehicle detector during the extendible portion of an actuated traffic phase having the right-of-way shall cause the retention of right-of-way by that traffic phase for one Unit Extension portion from the end of the actuation, but subject to the Maximum (extension limit).

f. Maximum (Extension Limit).
The Maximum or extension limit shall determine the maximum duration of time the right-of-way can be extended for a phase having successive detector actuations spaced less than a Unit Extension portion apart.

g. Initiation of Maximum or Extension Limit.
The timing of the maximum or extension limit shall commence (1) with the first actuation or other demand for right-of-way on a traffic phase not having the right-of-way or (2) at the beginning of the Green interval if an actuation or other demand for right-of-way has been previously registered on a traffic phase not having the right-of-way or, alternatively, the maximum may commence at the end of the Initial portion of the Green interval if an actuation or other demand has been previously registered on a traffic phase not having the right-of-way.

h. Transfer of Right-of-Way.
The actuation of any detector on a traffic phase not having the right-of-way shall cause the transfer of the right-of-way to that traffic phase at the next opportunity in the normal phase sequence provided that there has been an expiration of a Unit Extension portion with no continuing actuation or an expiration of the Maximum (extension limit) timing on the preceding phase having the right-of-way.

i. Rest in Absence of Actuation.
In the absence of detector actuation or assertion of recall switch(es), the right-of-way indication shall remain (rest) on the traffic phase on which the last actuation occurred.

j. Memory Feature.
Unless precluded by the operation of the nonmemory feature, the following memory retention shall be provided in the controller.

If the right-of-way is transferred by the operation of the Maximum or extension limit, the traffic phase losing the right-of-way shall again receive it without further actuation at the next opportunity in the normal phase sequence.

k. Pedestrian Timing Operation.
The following pedestrian function operation shall be provided.

1. Condition in Absence of Pedestrian Call.
In absence of pedestrian actuation or assertion of pedestrian recall function, pedestrian signals shall remain in a DON'T WALK condition.

2. Pedestrian Actuation Memory.
Pedestrian actuations received by a phase during steady or flashing DON'T WALK indications of that phase shall be remembered and shall cause the controller to provide pedestrian timing functions for that phase at the next opportunity in the normal phase sequence.

3. Nonextension of Pedestrian Intervals.
Successive pedestrian actuations shall not cause extension of the pedestrian intervals.

l. Other Operations Features.
In addition to specified functions, the following additional features shall be provided:

All phase detector inputs shall be supplied with detector delay disable capability.

All signal load outputs shall be individually fused with 10 ampere fuses.

Detector test switches and pedestrian (if specified) test switches shall be provided for each phase.

The permissive and force-off features shall be fully conditionable.

2. Functional Requirements.

a. Functional Requirements.
In addition to the basic functional requirements specified above, the controller shall provide the functional features for the applicable configuration, included in the NEMA Traffic Control Systems Standard TS-1.

E. Coordination of Traffic Actuated Controllers.

1. Requirements.
Means shall be provided within the controller to permit its interconnection into a coordinated traffic signal system when coordinated devices are added. As a minimum, this should include the provision of yield circuit or hold circuit accessible to interruption by commands external to the controller.

a. Hold Feature.
The controller shall contain a hold feature when asserted for a particular phase shall hold that phase in a rest condition. Upon release from hold, the phase shall immediately advance into the appropriate clearance interval or other unexpired portion of the Green, provided there is an actuation or an opposing phase.

b. Force-off Feature.
The controller shall contain a force-off feature which, when asserted, shall cause termination of the current phase, provided that phase is in the extension portion. In no case shall assertion of force-off cause termination in a clearance interval or during a minimum Green for vehicles or pedestrians.

c. Additional Features.
The controller and coordination device shall be capable of, but not limited to, the additional coordination features, including three cycles, four splits per cycle, three offsets per cycle, four permissible periods per split, four force-offs per split, one pedestrian permissive period per vehicular permissive period, and one dwell period per cycle.

2. NEMA Coordination Requirements.
In addition to the coordination requirements specified above, the controller shall contain tab coordination features for the applicable configuration included in NEMA Standard TS-1.

F. Master-Secondary Controller.

1. Purpose.
The purpose is to set forth functional requirements which apply to an interconnected actuated controller which is also equipped to serve as a master controller. For this the master controller will be located as designated in the contract documents.

2. Design Requirements.
The general design requirements in Article 2525.05, A and B shall apply, in addition to specific functional requirements described below.

3. Equipment.
A master-secondary controller shall consist of a complete interconnected controller equipped with the necessary apparatus to provide supervisory functions for operation of a system of interconnected actuated and pretimed controllers.

4. Supervisory Functions.
The master controller shall be equipped with a solid state programmable plug-in module or controller accessory unit with time-based coordination capabilities. This unit shall provide as a minimum, but not limited to, these capabilities:

a. Synchronization pulse generation for offsets.

b. An offset interrupter or equivalent device for decreasing the disruption to interval timing caused by large offset changes.

c. Hand operated flash control switch for transfer of traffic control signal lights at each interconnected controller to give flashing indications.

d. Complete compatibility with actuated controller coordination units specified in Article 2525.03, C.

e. Programming capability as a minimum, but not limited to, time of day, day of week, week of year, with daylight savings selection.

2525.04 INDUCTIVE LOOP VEHICLE DETECTOR.

A. Design Requirements.

1. Operation.

a. General.
Detectors shall be designed to meet requirements of NEMA Traffic Control Systems Standard TS-1, most current revision.

The detector shall provide reliable detection and maintain an output indication for a period of not less than 3 minutes for a vehicle that causes a 0.02% change in the total inductance of the loop and lead-in system, as measured at the detector loop input terminals. The detector shall provide operation as above with a loop system having any or all of the following characteristics:

1) A shunting resistance of 10,000 ohms or greater to a common or circuit ground bus.

2) A loop system quality factor (Q) of not less than 5.0, when connected to the detector being tested. Q is defined as the ratio of the resonant operating frequency over the half-power band width.

3) A total or equivalent inductance within the range of 40 microhenrys to 700 microhenrys at the detector loop input terminals.

A sensitivity adjustment or selector shall be provided to allow selection of a high, medium, or low sensitivity adjustment. Increments shall include: High, 0.02%; Medium, 0.06%, 0.01% (±); Low, 0.125%, 0.025% (±).

b. Loop Energizing and Detector Sensing Circuits.
The detector shall provide reliable detection of licensed motor vehicles. The detector shall provide an output (switch closure) only when vehicles are passing or stopped over the loop and shall detect all vehicles passing over the loop at speeds up to 80 mph (130 km/h).

1) When first turned on, while tuning or being tuned, the detector shall provide a continuous output pulse (switch closure), plus a visual indication, in both the presence and pulse modes of operation. On power failure, or loop failure that would cause the inductance to exceed the tuning range, the detector must place a continuous call.

2) To prevent mutual interference "cross-talk," the detectors shall be provided with a three-position frequency mode switch on the front panel.

3) The detector shall be designed to be initially tuned to the loop and provide for automatic drift compensation.

4) The operation of the detector shall not be affected by changes in the inductance of the loop caused by environmental changes, such as rain, hail, snow, temperature, and humidity, nor shall the sensitivity be markedly affected.

c. Accuracy.
The detector shall be able to detect all licensed vehicles, including motorcycles, accurately.

2. Detector Output.
The detector output (switch closure) to the associated traffic control equipment shall be provided by means of a relay. The relay shall have a mechanical life of at least 1,000,000 operations. The contacts shall have a rating of at least 1.0 ampere at 120 volts AC or DC.

3. Power Supply.
The primary of the power supply transformer shall be fused with a 1/4 inch (6 mm) diameter, 1 1/4 inches (32 mm) long, 250 volt fuse of suitable current rating. An extractor-post fuse holder shall be provided. The fuse rating shall be marked by the fuse holder.

4. Visual Indicator.
A LED shall be used to provide a visual indication of each vehicle detection. The indication must be readily visible in indirect sunlight.

The LEDs shall have a minimum design life of 20,000 hours at rated voltage.

5. Dielectric Strength.
The detector shall withstand a dielectric strength test of 1,250 volts, 60 hertz, AC applied between the 120 volt AC line-supply circuit and the terminals for the external loop, for a period of 1 minute.

6. Interchangeability and Design Life.
All modules and components of the same type shall be interchangeable. The design life of all components, under conditions of normal operation, shall not be less than 5 years.

7. Marking.
Each detector shall be marked with the manufacturer's name, model, catalog, or type number, and serial number. The electrical input rating (voltage, frequency, and wattage) shall be included in the marking.

B. Input/Output Receptacle.

1. Function Assignment.
Input and output connections for the detector shall be made to a type MS-3102-A-18-1P box receptacle with 10 male contacts. A plastic cover shall be provided on the receptacle. The pin positions of the input/output connector shall be assigned as follows:

Pin No.	Function
A B C D E F G H I J	120 vac (-) Output Relay Common 120 vac (+) Input from Loop Input from Loop Output Relay N.O. Output Relay N.C. Chassis Ground Spare Spare

2. Plug and Cable.
A plug, type MS-3108-B with type 18-1S insert, with 10 female contacts shall be furnished, wired with leads of No. 18 AWG stranded, color-coded wire with 300 volt insulation. A type MS-3057-10 cable clamp and boot shall be provided for strain relief. The leads shall be 10 feet (3 m) in length, the first 16 inches (0.4 m) of leads, from the plug, shall be enclosed in cotton braiding. No terminals are required on the leads.

C. Components.

1. Inductors and Transformers.
All inductors and transformers shall have their windings insulated and shall be impregnated to exclude moisture. All wire leads shall be color coded.

2. Resistors and Capacitors.
All resistors and capacitors shall be insulated and shall be marked with their resistance or capacitance value. Resistance and capacitance values may be indicated by the Radio Electronics Television Manufacturer's Association (RETMA) color codes. All electrolytic capacitors shall be marked to indicate polarity and voltage.

3. Printed-Circuit Boards.
All printed-circuit boards shall be at least 1/16 inch (1.5 mm) thick and shall be made of glass-cloth silicone NEMA type G-10 glass epoxy, or equivalent. The conductor material shall be copper, 0.0027 inch (70 µm) thick, having a weight of 2.0 ounces per square foot (610 g/m²), with a protective solder coating. All printed-circuit board connectors (male and female) shall be gold plated over the copper base. The printed circuit-boards shall be securely mounted in such a way as to prevent flexing or bending of the boards, and shall be easily removable for servicing or replacement.

4. Wiring.
All interconnecting wires shall be insulated No. 22 AWG or larger, suitable for 180°F (82°C) operation.

5. Solid State Circuitry.

a. Transistors, integrated circuits, or semiconductor diodes shall be used for all amplifying, detecting, rectifying, counting logic, and regulator circuits. No vacuum or gas tubes shall be used except for pilot lights. Transistors, integrated circuits, and diodes shall be marked with their type number and shall be types listed by the RETMA. No electro-mechanical timers, synchronous motors, or relays shall be employed, except as specified in Article 2525.01, B.

b. All electronic and electrical components must be of standard manufacture and available from a source other than the manufacturer of the loop detector unit.

c. No modifications to the circuit, parts substitutions, or changes in the function or form from the original equipment list shall be allowed without prior approval of the Engineer.

D. Wiring Diagrams.
Wiring and schematic diagrams, descriptive parts lists, and instruction and maintenance manuals shall be provided for all items furnished under these specifications. Equipment or unit modifications as approved must be accompanied by revised diagrams with the first shipment of the modified units. Tables, charts, or equations for use in designing loops of various sizes and configurations shall be provided. Five complete sets of diagrams, manuals, etc. shall be furnished to the Engineer with each order.