ST950S Plus+ Installation and Commissioning Manual
Table 10. I/O Card LED (continued)
Led Indicator
Function
Meaning
Yellow 1
Imbalance LED
On
Voltage Imbalance be
tween PSU 1 and 2
Yellow 2
Imbalance LED
On
Voltage Imbalance be
tween PSU 2 and 3
Red x 3
Overload
On
Too much current is be
ing drawn from a PSU
PSUs are factory adjusted and should not give a voltage imbalance. If it occurs, solving an Imbalance
issue involves the careful adjustment of the connected PSUs. Please contact Yunex Traffic Engineering
in Poole for assistance before attempting any adjustment.
Should an Overload LED become illuminated the likely causes are incorrect street wiring from the CTB
or a badly installed traffic system i.e. too many nodes connected to a particular power source.
As well as the LED indication the controller will also record the above faults in the fault table.
3.8.5. Parts
Redundancy Module 667/1/53185/000
3.9. ST950 Plus
+
CPU Card
The CPU card for Plus
+
is common with that used for LV and ELV versions of the ST950. There are
two variants of the CPU card which differ only in the amount of RAM available on the EFC module. For
Plus
+
, only the 128M RAM variant is appropriate.
3.9.1. General
The CPU Card controls the system. It holds the controller configuration and performs the function of
configuration, control and management. The primary external data interfaces are shown in
.
One serial phase bus and two GSPI bus connectors are available on 3 separate RJ45 sockets on
the rear of the CPU Card. The fourth RJ45 socket is reserved for a future GSPI Manual Panel and is
blanked off and should not be used.
The RJ45 socket marked “LSLS” on the ST950 CPU Card is connected to the first position CTB.
Solving an Imbalance issue involves the careful adjustment of the connected PSUs. Please contact Yunex
Traffic Engineering in Poole for assistance before attempting any adjustment.
Flickering - lightly loaded systems may show one or more flickering Imbalance LEDs this is not a fault.
A severe voltage imbalance could lead to an overload on one PSU. An overload indication provides early
warning of a possible PSU shutdown: the PSU will self-protect if the overload becomes significant.
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