Advanced M52 Microprocessor User's Guide
ADVANCED M52UMCT2019 COLOR
54
Fault Finding
In some cases, determining the cause of a fault requires a fair amount of technical knowledge
and skill. The following fault finding charts are given as a guide for the service personnel to
locate the common faults which may be encountered in the unit.
High Temperature Alarm
High temperature
alarm
Main temperature
higher than "Temp.
Hi Limit" setting
Wrong setting in
"Temp. Hi Limit"
Set "Temp. Hi
Limit" 3-5°C
higher than
"Temp. setpoint"
Abnormal site
condition
Check opened
doors/windows
or abnormal site
condition
Main
temperature too
high ?
Inoperative cooling
system
Check cooling
system
operation
yes
no
Low Temperature Alarm
Low temperature
alarm
Main temperature
Lower than "Temp.
Lo Limit" setting
Wrong setting in
"Temp. Lo Limit"
Set "Temp. Lo
Limit" 3-5°C
lower than
"Temp. setpoint"
Abnormal site
condition
Check opened
doors/windows
or abnormal site
condition
Main
temperature too
low ?
Inoperative heating
system
Check heating
system
operation
yes
no