Fault Finding - TB Controls TC02 Operation & Maintenance Manual

Operations & Maintenance Manual
9.

Fault finding

Fault Indication:
module add 0
No power @ LCD plate
Sensors
Overheat Cut-out
BMS Connections
PIR Contact
Slave X Comms Fault
MODBUS network
Doc: TC02 O&M
Final
Status: issue: 11
Check:
The LCD has power but no data comms. Check wiring between LCD
wall plate and unit mounted control board. Refer to wiring diagrams.
Correct cabling has been used "Beldon
8723".
Wiring between LCD wall plate and unit mounted control board. Refer to
wiring diagrams.
Check main power supply into unit.
Check transformer fuse (2A) on 24VAC supply.
Check controller has 24VAC supply and 12VDC from controller.
Check remote LCD wall plate has been earthed.
Check connections @ unit mounted control board, also making sure
colours are correct to wiring diagram.
Check fans are running. Check unit air inlet & discharge are not
blocked.
Should remote LCD plate read BMS/Time switch unit off, this may either
be the main BMS system holding the units off or the N/O or N/C may
need to be altered. The contacts can be altered by accessing the
engineering mode. Should units be master/slaved it will also inform
you of this.
Should the LCD plate read "unoccupied unit off" the PIR contact may
need to be altered, which can be accessed in the engineering mode or
the PIR sensor may not have been activated.
Should the LCD plate read "Slave X Comms Fault" The Belden cable
between master and slave units has become damaged, disconnected or
shorted.
Check polarity of red and black wires at BMS connection, they may
need to be reversed for correct operation. Make sure all network cables
lengths have the shield wire connected to local earth at one end (jumper
link on TC02). An unconnected shielded cable is worse than an
unshielded cable!
Check network address with BMS system. Each TC02 controller that is
connected to the network must have a different MODBUS address
(default is 1).
Check baud rate, changeable from firmware V4.13 and above.
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