2010 Construction and Material Specifications - Ohio Department of ...

733.03
(7) Failed State Output Circuits.
(a) Use an electro-mechanical relay to provide the
FAILED STATE output circuit. Ensure that the relay contacts are normally closed
(FAILED STATE). In a NON-FAILED state (relay coil energized), ensure that
the contacts are open. The function of this output circuit is to initiate flash
operation within the cabinet and transfer field circuits from the switch pack outputs
to the flash bus during a FAILED STATE.
(b) Furnish relay contacts that are rated for a minimum of
3 amperes at 120 V ac and 100,000 operations. Ensure that the contact
opening/closing time is 30 ms or less. Furnish contacts that present a minimum
impedance of 50,000 ohms in the open state.
(c) Ensure that the Stop Time output is active whenever
the output relay contacts are in the FAILED STATE (closed). Ensure that it is
inactive whenever the output relay contacts are in the NON-FAILED (open)
STATE.
(8) Monitor Unit Reset. Furnish a front panel momentary
SPST pushbutton switch labeled “RESET” to reset the Monitor to a Non-FAILED
state and restores normal monitoring operation. Position the switch on the front
panel so that the switch can be operated while gripping the front panel handle.
Ensure that the External Test Reset input line resets the
Monitor circuitry to a Non-FAILED state and restores normal monitoring
operation. Optically isolate it from the internal circuitry. Ensure that a reset
issuance by either source (Unit Reset) is triggered by only the leading edge of the
input signal (this will prevent a constant reset due to either a switch failure or a
constant external input). Ensure that a constant reset input is ignored within 5
seconds of issuance.
(9) Input Impedance. Ensure that the input impedance for all
monitored AC inputs are 200 kilohms ± 100 kilohms.
(10) Connectors. Furnish PCB 28/56P Type Monitor and
Conflict Program Card Connectors. Ensure that all edge connectors use the
“bifurcated bellow” type contact or equivalent.
(11) Door Ajar Circuit. Connect pin 24 to pin 25 on the
Monitor PCB at the edge connector and ensure that it is capable of carrying one
ampere per CalTrans specifications.
(12) Handle. Ensure that the handle placement and design is
such that no interference between the handle and a closed cabinet door exists.
panel.
(13) Fuse Holder. Furnish low profile fuse holders on the front
c. Functional Requirements.
(1) General. The Monitor monitors the cabinet for conflicts
and unsafe operation. If an unsafe condition exists, the Monitor will enter into a
FAILED state. This places the cabinet into flash operation and applies STOP
TIME to the controller unit. Ensure that the Monitor is designed to monitor red
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