ST950S Plus+ Installation and Commissioning Manual
Note that:
•
Both loops of an SDE/SA or U/D pair must be assigned to the same Smartloop device.
•
N+1 count inputs are not currently supported by Smartloop and must continue to use standard
loop detector cards (e.g. SLD4).
2.2. The Principles of Plus
+
Wiring
2.2.1. Voltage Drop in Plus
+
Network
The IET regulations have defined values for voltage drop within a network to ensure that any
equipment connected to that network is maintained within its likely operating range. Within a traffic
control signals network the rule of thumb of 4% does not necessarily apply directly, as signals have
their own operating range and requirements. The applicable design and maintenance limits are defined
in our design and equipment handbooks for our signals, (Note signals supplied by third parties may
have different operating characteristics and ranges and the design and maintenance limits for those
should be obtained from the OEM).
For Plus+ the complex design calculations have been built into our Plus+ junction layout design tool.
The equipment will then inform users / maintainers if the supply as seen at any pole / node is outside to
the normal operating range for a period.
2.2.2. Wiring
The Plus
+
system elements are wired up by a collection of 4-way street cables (armoured) and 6-way
(dropper) cables. The diagram below outlines the principles behind the wiring particularly with regards
to cable types and colours.
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