TC12 Installation, Commissioning & Maintenance Handbook
maxim
reduced if the actual voltage being monitored is at the lower level, i.e. if a 50-0-50
V RMS supply (derived from a transformer) is used but the monitoring is on the
240 V en the limits do not need to be reduced.
For example, 8 pedestrian plus 8 wait indicator.
For example, 8 vehicle plus 4 pedestrian plus 4 wait indicator.
vehicles the
mit is greater, i.e. 6 vehicle plus 2 pedestrian plus 2 wait indicator.
at 50-0-50 V sites, the signs must be driven
wrrent
characte
um loads when a 50-0-50 V RMS mains supply is used. The limits are only
RMS side of the transformer, th
If the nominal load current (including red/ambers) of a particular controller
output exceeds 4.0 A RMS, at nominal mains voltage, then that output
should be split and treated as two separate outputs (although the same
voltage sensor can be used for both).
The limit of 8 applies if they are all vehicle signals. For fewer than 8
li
To allow monitoring of tube type signs
ith the 50-0-50 V supply and the tubes must have the standard voltage-cu
ristic.
CAUTION The current sensors may produce a high voltage, when
terminated into the OTU board, if current is passed through the core.
not
he Current transformers measure the current flowing in conductors that are
idal and one side is marked with a red spot to
dicate the input direction. The Live conductor(s) should pass from the controller
latch housing to provide a complete sensor assembly which plugs into
L1 on the OTU board. Referring to Figure 35, the red wire connects to the
r
corresp
from nu be anchored by passing a
YWRAP or equivalent through the sensor hole and around a suitable fixing point.
Up to 23 current transformers can be used per Outstation when equipped with
LMU facilities.
T
passed through their core. To maintain the correct relationship between the
current flowing in the conductors and the output from the sensor, the sensors must
be connected the correct way round.
The current transformers are toro
in
output terminal(s) through the centre of the current transformer, entering the side
with the red spot marker, and on to the lamp(s).
The output wires from the current transformer are red (positive) and white
(negative) and are terminated with Berg mini PV terminals which are clipped into a
Berg mini
P
equired number LMU input shown with a +, and the white wire connects to the
onding - input. Inputs should normally be allocated consecutively starting
mber 1. The current sensors should then
T
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