STATE OF OHIO DEPARTMENT OF TRANSPORTATION SUPPLEMENTAL SPECIFICATION 919 RAILROAD PREEMPTION INTERFACE January 17, 2014 919.01 Traffic Signal Cabinet and Controller Unit General Requirements 919.02 Approved Controllers 919.03 Nomenclature and Terminals 919.04 Harness 919.05 Preemption Input Test Switch Panel 919.06 Indicator Panel 919.07 Railroad Interface 919.08 Interconnect Cable 919.09 Controller Functionality 919.01 Traffic Signal Cabinet and Controller Unit General Requirements The interface consists of six twisted-pair circuits and associated equipment. Five circuits shall communicate from the railroad crossing enclosure to the traffic signal cabinet and one from the traffic signal cabinet to the railroad enclosure and shall function as follows: 1. Advance Preemption. This circuit will notify the traffic signal controller of an approaching train prior to the operation of the active warning devices. Two relays or both channels of an isolator card are required. The railroad will return a normally open and a normally closed circuit. Preemption will be initiated when the normally closed circuit opens. The normally open circuit closes when preemption is initiated indicating the proper functioning of the supervision circuit. 2. Simultaneous Preemption. This circuit will notify the traffic signal controller of an approaching train at the point the active warning devices begin their operation. One relay or one channel of a DC isolator card is required. The railroad will return a normally closed circuit which opens when the railroad warning devices begin to operate. 3. Island Occupied. This circuit will notify the traffic signal controller of the arrival of the train at the island circuit. One relay or one channel of a DC isolator card is required. The railroad will return a normally closed circuit which opens when the train occupies the island circuit. 1 4. Gate Down. This circuit will notify the traffic signal controller when the gate(s) controlling access to the track(s) is lowered to within 5 degrees of horizontal. One relay or one channel of a DC isolator card is required. The railroad will return a normally open circuit which closes when the gate(s) controlling access over the crossing approaching the intersection is lowered. 5. Gate Up. This circuit will notify the traffic signal controller when all gates at the crossing are raised. One relay or one channel of a DC isolator card is required. The railroad will return a normally closed circuit which opens when all the gates at the crossing are raised. 6. Traffic Signal Health. This circuit will notify the railroad warning system whenever the traffic signal has entered conflict flash or the power has failed. This is an output from the traffic signal controller to the railroad control equipment. It shall be 12 VDC which is output whenever the traffic signal is not in flash and power is on. If the traffic signal is in flash or the power is off, the output shall be 0 VDC. A simple method is to use a 12V transformer and rectifier connected to the coil of the signal bus control relay or mercury contactor. The intent is that the traffic signal health output will be de-energized even if the signal bus contactor output remains closed. The output should be fused. 7. An output shall be included to provide for the operation of illuminated blank-out signs. The signs shall be illuminated whenever the controller unit is in railroad preemption as indicated by an output circuit provided by the controller unit. A solid state relay, Crydom part number D1210 or equal mounted on the interface panel or unused load switch element shall be used to illuminate the blank-out signs. 8. If a relay interface is provided, the relays connected to the railroad equipment shall operate at 24 VDC. A 24 VDC isolated NEMA TS-2 power supply shall be provided and connected to the preemption isolation panel assembly to power the relays and indicator lights. The power supply outputs shall not be connected to any other voltage source or common such as logic groundAC neutral or earth ground. The power supply shall be capable of providing enough current to simultaneously energize all of the relays and illuminate all of the indicators at maximum temperature plus a 20 percent de-rating. The power supply shall be capable of providing a carryover of 50ms at full load. The input and the output of the power supply should be appropriately fused and the power supply should be fully isolated with no grounded conductors. 24 VDC relays should be Magnecraft 788XBXM4L-24D or pin-for- pin compatible equal which include an internal LED indicator. 120 VAC relays shall be Magnecraft 788XBXM4L-120A or pin-for-pin compatible equal which include an internal LED indicator. Relays shall be installed in an appropriate socket, Magnecraft 70-463-1 or pin-for-pin compatible equal. Hold down clips, Magnecraft 16-1351 or equal shall be provided for each relay. Adequate terminals, numbered or labeled and identified on the 2 wiring diagram shall be provided for all field connections and all internal connections. The relays and terminals shall be mounted on a suitable aluminum panel located in an area accessible for inspection and connection. 9. If a solid state interface is provided, the isolator cards shall be mounted in a separate 4 position rack. Three Model 242 DC isolator cards and a 24 VDC, 5 Amp power supply card shall be provided. The power supply shall be capable of providing carryover in the event of primary power loss for a minimum period of 35 ms at full rated load. Adequate terminals, numbered or labeled and identified on the wiring diagram shall be provided for all field connections and all internal connections. The terminals shall be mounted on a suitable aluminum panel located in an area accessible for inspection and connection. The rack shall be mounted in an area suitable for viewing of the card mounted indicators and for removal and insertion of cards. The input configuration should be as follows: Card 1 Input 1 – Advance Preempt Normally Closed Card 1 Input 2 – Advance Preempt Normally Open Card 2 Input 1 – Simultaneous Preempt Card 2 Input 2 – Island Card 3 Input 1 – Gate Up Card 3 Input 2 – Gate Down 919.02 Approved Controllers The following approved controllers implement the basic functionality of the ODOT standard Railroad Preemption Interface. The minimal functionality shall implement the Advance Preempt (AP) and Gate Down (Gate Down) features. This shall be implemented with a minimum of two controller inputs (AP-NC and GD) if AP circuit supervision is provided external to the controller. If the supervision is implemented internal to the controller, then a minimum of three inputs (AP-NC, AP-NO, GD) shall be provided. A) With in-cabinet Relay Interface board: 1) 2070L with LA-TSCP V software (w/ C11) 2) Econolite ASC/3 3) Siemens 2070L with SEPAC software B) With solid-state (DC isolator) interface: 1) 2070L with LA-TSCP V software (w/ C11) 2) Econolite ASC/3 3) Siemens 2070L with SEPAC software C) With IEEE 1570 interface: 1) 2070L with LA-TSCP V software (w/ C11) 2) Econolite ASC/3 D) With CTC Railroad Preemption Interface Card: 3 1) 2070L with LA-TSCP V software (w/ C11) 2) Econolite ASC/3 3) Siemens 2070L with SEPAC software 919.03 Nomenclature and Terminals The nomenclature and terminals shall be as indicated on the interface panel wiring diagram. Terminals shall utilize a “cage-clamp” design such as manufactured by WAGO Corporation or equivalent. Terminals which provide “side wipe” connections or set screws are not acceptable. See below for additional information regarding terminal numbers. 919.04 Harness The appropriate harness (MS D, C11 or other) for the specific controller unit provided shall be furnished and connected to the preemption interface panel. 919.05 Preemption Input Test Switch Panel A preemption input test switch panel with six test switches shall be provided and mounted in a convenient location within the controller cabinet. The railroad circuits shall be connected through the test switch panel to directly simulate the input from the railroad. Each switch shall be labeled exactly as indicated below by use of a silk screened legend or an engraved plastic plate. Rub-on, adhesive or other markings which are not permanent are not acceptable. The following switches shall be provided: 1. Advance Preemption Test – This switch shall be Double Pole/Double Throw (DPDT) and arranged such that the up position is normal and the down position is test. When up, the two advance preemption circuits from the railroad should pass through the test switch. When down, the advance preempt normally closed circuit shall be open and the advance preemption normally open circuit shall be closed. This switch shall be labeled “ADVANCE PREEMPTION NORMAL” for the up position and “ADVANCE PREEMPTION TEST” for the down position. 2. Simultaneous Preemption Test – This switch shall be Single Pole/Double Throw (SPDT) and arranged such that the up position is normal and the down position is test. When up, the simultaneous preemption circuit from the railroad shall pass through the test switch. When down, the simultaneous preemption circuit shall be open. This switch shall be labeled “SIMULTANEOUS PREEMPTION NORMAL” for the up position and “SIMULTANEOUS PREEMPTION TEST” for the down position. 3. Island Circuit Test – This switch shall be SPDT and arranged such that the up position is normal and the down position is test. When up, the island preemption circuit from the railroad shall pass through the test switch. When down, the island preemption circuit shall be 4 open. This switch shall be labeled “ISLAND CIRCUIT NORMAL” for the up position and “ISLAND CIRCUIT TEST” for the down position.