TestEquity 123HS, Operation And Service Manual

Page: 41 / 53

Chapter 7 – Maintenance
TestEquity 123HS Temperature/Humidity Chamber Page 7-11
Troubleshooting
SYMPTOM CONDITION CAUSES
Does not heat up at all.
1. If F4 controller light 1A is ON
(F4T upper PWR bar is 100%),
circulator fan is ON, circulator
fan is ON, the Heat light is
OFF.
2. If F4/F4T Controller light 1A is
ON, circulator fan is ON, 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 F4 controller light 1A is OFF
(F4T upper PWR bar is 0%).
1. Solid State Relay SSR1 is
defective (shorted).
Does not cool at all.
1. If F4 controller light 1B is ON
(F4T upper PWR bar is 100%),
DigitalOut 8 (F4T Compressor
Output) is ON, the Cool light on
front panel is OFF, both
compressors are OFF.
2. Setpoint is low than chamber
temperature but F4 DigitalOut 8
(F4T Compressor Output) 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 (or SV3 if
in Humidity mode) may be
defective in closed position.
Refrigeration leak, plugged
capillary tubes.
Pressure switch DPS1 trips.
(on rear right 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).
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 –35°C.
1. No bubbles in the 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.