Despatch 926E Equipment Manual (C-155)Rev 2/11 - Manual (Page 56)

51
Troubleshooting
TROUBLE
PROBABLE CAUSE
No controller display reading when power
switch is on.
Loose wiring.
Faulty transformer (240V or 208V units only).
Faulty readout.
Power cord not plugged into outlet. Outlet not powered.
Defective line fuse (F1).
Defective POWER switch (S1).
Defective power cord.
Blowing line fuse when power switch is
turned on.
Defective (grounded or shorted) heater (HTR-1).
Defective motor(s) (shorted).
Defective solenoid valve (shorted) (1).
Short in filter, transformer (if installed) or control.
Shorted wiring, or loose connection touching chassis.
Chamber temperature differs from set point
indication.
Defective sensor (1 or both).
Control input parameters incorrect.
Control out of calibration.
Defective control.
Lack of operation of appropriate heat (1) or
cool (2) LED when control set point differs
from display by more than 0.3

C.
Defective controller.
Control output and PID parameters incorrect.
Failure to control at a low temperature when
cool (2) LED is on.
Cylinder valve not open.
Lack of liquid coolant.
Clogged CO
2
filter.
Clogged orifice.
Clogged line.
Solenoid valve will not open.
Defective solid state relay (SSR2).
Failure of chamber to heat when heat (1)
LED is on.
Faulty heater fuse (F2).
High limit (Dial) set below chamber temperature.
Defective solid state relay (SSR1).
Defective contactors (K1 or K2).
Defective heater (HTR-1).
Defective heater cable.
Solenoid valve will not close.
Defective control.
Failure of solenoid valve to close when cool
(2) LED is off.
Ice in valve.
Defective valve.
Defective solid state relay (SSR2).
Defective control.
Failure of solenoid valve to open when cool
(2) LED is on.
Defective valve.
Defective solid state relay (SSR2).
Defective control.