Chapter 8 – Maintenance
TestEquity 123C Temperature Chamber
Page 8-9
Troubleshooting
SYMPTOM
CONDITION
CAUSES
Does not heat up at all.
1.
If F4T upper PWR bar is 100%
(F4 controller light 1A is ON),
circulator fan is ON, circulator
fan is ON, the Heat light is
OFF.
2.
If the Heat light is ON.
1.
Solid State Relay SSR1 is
defective (open).
2.
Heat Limiter HL is open. Heater
HT1 is open.
Heats up too slow.
1.
Does not meet published
specifications.
1.
Chamber interior is overloaded.
Circulator motor is not turning.
Port plug is not in port. Verify
that input voltage is within
tolerance.
Heat is on all the time.
1.
If F4T upper PWR bar is 0%
(F4 controller light 1A is OFF).
1.
Solid State Relay SSR1 is
defective (shorted). Defective
output 1A on F4 Controller.
Does not cool at all.
1.
If F4T upper PWR bar is 100%
(F4 controller light 1B is ON),
F4T Compressor Output (F4
DigitalOut 8) is ON, the Cool
light on front panel is OFF, both
compressors are OFF.
2.
Setpoint is low than chamber
temperature but F4T
Compressor Output (F4
DigitalOut 8) is not ON.
3.
If the Cool light is ON,
compressors are ON.
1.
Pressure switch PS1 or PS2 is
tripped.
2.
Controller is mis-configured.
Re-enter values as documented
in the controller manual.
3.
Solenoid valve SV1 may be
defective in closed position.
Plugged R-508B capillary tube.
Refrigerant leak.
R-404A pressure switch
DPS1 trips. (on rear left
side)
1.
Trips after operating for a while.
2.
Trips immediately after turn on.
1.
Ambient temperature may be
too high, over 90
°
F. Dirty
condenser, inadequate clearance
from back of chamber to wall.
2.
Low charge (leak).
R-404A sightglass has
bubbles or does not look full.
1.
During all running conditions.
2.
Only when cool light is cycling.
1.
Low charge (leak).
2.
No problem. This is normal.
Cools too slowly or does not
reach –68°C.
1.
R-508B standby is ok, no
bubbles in R-404A sightglass.
1.
Chamber interior is overloaded.
Test sample is energized, giving
off heat. Circulator motor is not
turning. Port plug is not in port.
Door is not sealing completely.
Ice on evaporator.
