Fault Finding Procedures For Remote Units; Perform A 0V Continuity Check; Check Terminations On Remote Units - Baldwin Boxall OmniCare Installation Manual

C O M M U N I C A T I O N S
6.2 F

6.2.1 Perform a 0V Continuity Check

6.2.2 Check Terminations on Remote Units

OmniCare issue 1
F
AULT INDING
R
EMOTE
If during Commissioning an "Open Ended" loop (i.e. only
connected at the "A" termination on the Control Panel) the
Remote Units are not all detected then the following procedures
can help to identify and locate the fault(s).
C
A U T I O N
The OmniCare EVC System Remote Units can be damaged if
either of the following situations occur:
• If Power is connected across the Data pair,
• If Power is reversed i.e. 0V and +V swapped.
With the mains and one end of the Loop disconnected at the
Control Panel ensure the 0V cable has continuity around the loop
between the "A" and "B" ends of the circuit.
N : The 0V cable is the only cable that should have continuity around
OTE
the loop.
If the 0V cable does not have continuity around the loop then this
must be investigated and resolved before attempting to
Commission the system again.
It may be necessary to check the continuity of the loop "point to
point" to locate the fault. It is possible to determine the location
of a break in the 0V cable by linking one end of the 0V cable to
Earth, and then checking the resistance between 0V and Earth at
each Remote unit in turn along the loop. When 0V is no longer
connected to Earth the location of the break is identified.
The majority of problems encountered during commissioning are
due to poor, loose or incorrect terminations on Remote Units.
P
ROCEDURES FOR
U
NITS
OmniCare EVC System
Installation & Commissioning Manual
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