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IM-P481-04
CTLS Issue 4
50
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TRANSLATION RUN OVER
Fault
Possible cause
Remidial action
Unit does not
power up
Loss of incoming supply
Check incoming supply
Internal fuse blown
Check all mains fuses F1 - F4 and Control fuses
AF1, CF1 - CF7
Loss of 24 Vdc
supply
Internal fuse blown
Check all mains fuses F1 - F3 and Control fuses
CF1 - CF7
Field wiring fault
Sequentially disconnect the field wiring for all 24 Vdc
supplies to see if supply is restored
Loss of 24 Vac
supply
Internal fuse blown
Check all mains fuses F1 and F2 and Control fuses
AF1
PT100 signal not
reading correctly
(T1 - T5)
Field wiring fault
Check termination of 3 wire PT100 terminats (X1 - X5)
and PT100 head
Faulty PT100
Check compensated resistance
Bypass pump
does not operate
Field wiring fault
Check wiring of pump to
terminals X11
Internal fuse blown
Check mains fuse F4
Bypass valve does
not operate
Field wiring fault
Check wiring of bypass valve to terminals X12
Check setting of deviation
alarm on HMI
Ensure not to set 0, the setting should be 2C
Remote set point
is not showing
correctly
Scaling value incorrect
Ensure that the minimum and maximum
engineering units from the remote set point match
those on the HMI (this data is found on the Spirax
Sarco engineers 4-20 mA page)
Polarity of 4-20 mA
incorrect
Reverse polarity and wire as per electrical
drawings
5. Fault finding