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9.1.13.2
Loop Detector Surge Protectors
Loop detector surge protectors (see Section 6) shall be furnished and installed in
cabinets which house loop type vehicle detectors as required by these Specifications, the
plans or the bid list. A loop detector surge protector shall be used to protect each
detector loop input to each loop type vehicle detector in the cabinet. The protectors
shall be installed directly on the loop field terminals. The grounding conductor shall be
as short and straight as possible. The grounding conductor shall provide grounding of
each protector that is the electrical equivalent of an A.W.G. #6 (minimum) copper
conductor.
9.1.13.3
Communications Surge Protectors
If the plans or the bid list require that the cabinet house a controller or communications
equipment that is to be interconnected with other locations via telephone lines or
paired-conductor interconnect cable and using multiplexed communications techniques,
the cabinet shall be furnished with communications surge protectors (Type Q and Type
SC as appropriate) conforming to the requirements of Section 6 of these Specifications.
The cabinet shall contain a sufficient number of each type of communications surge
protector to protect the equipment in the cabinet from surges which may be introduced
from each communications pair that is actually connected to the equipment in the
cabinet. A surge protector shall also be furnished for the voice communications circuit,
if any. Surge protection is not required for communications pairs that are merely
spliced in the cabinet with no connection to the equipment.
9.1.13.4
Signal Circuit Surge Protectors
All vehicular signal load circuits and all pedestrian signal load circuits shall have metal
oxide varistors (V150LA20 or approved equivalent) connected to their load terminals to
protect the load switches from surges on the signal cables.
9.1.14
Equipment Connection
9.1.14.2
It shall be possible to remove each item of equipment from the cabinet without
disconnecting individual wires. The equipment shall either be connected to the cabinet
by means of harnesses with suitable MS-type, or other multi-pin connectors, or be
mounted in card racks that provide for automatic connection of the card when it is
inserted in the rack. The connector of any harness carrying voltages in excess of 50 V
shall be grounded, if metal.
9.1.14.3
Functionally
Traffic Signal Specifications
April 1998
equivalent
equipment
shall
be
electrically
and
mechanically
Section 9
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