PSB NG-SR-21-4-DDP Instruction Manual page 36

XIII. TROUBLESHOOTING – cont'd
Symptom
Cooler Overload alarm
Excessive process
pressure drop
Poor dew point
Cooler Outlet
Temperature High
Alarm
Heater Sheath Over
Temperature Alarm
Heater Chamber Alarm
Thermocouple Failure
Alarm
NG-SR IOM
Probable Cause
Overloads tripped
Contactor not energized
Motor failure
Excessive process flow
Valves not in correct position
for regeneration
Filters plugged
Dew point sensor isolated
No flow across sensor for
long period of time
Excessive inlet moisture
Regeneration problem
Cooler fan not running
Ambient temperature high
After-cooler dirty
Thermocouple failure
Blower failure
Flow blocked
Heater thermocouple failure
Low regen flow
Heater contactor mechanical
problem
Valve closed
Blower problem
Blower fuse blown
Low regen flow
Wiring problem
Thermocouple bad
PLC problem
35
Remedy
Reset
Check voltage on coil. Replace
as required
Check windings and replace as
needed.
Reduce to design
Open valves "V3" and "V4".
Replace filter elements
Open ¼" valves to flow gas
across sensor.
Pass flow through dryer. Then
monitor. Slightly close V-6 to
create flow across sensor.
Regenerate unit with greater
frequency or reduce moisture
input or flow.
Restart regeneration and monitor
heater output and cooler
temperature.
Refer to symptom "Cooler
overload alarm"
Regenerate when air temperature
is < 100°F
Clean dirt and debris from fins.
Test and replace as needed.
Refer to symptom "Blower
overload alarm"
Open valve "V3" to increase flow.
Test and replace as needed.
Close blower bypass
Verify contactor operation and
replace as needed.
Verify that V3 and V4 valves are
open during regeneration.
Blower mechanical issue
(coupling or blower internal
binding)
Check and replace as necessary
Close blower bypass
Check for loose connections
Remove and replace
Check power to thermocouple
Check thermocouple module
PSB INDUSTRIES