Chapter 8 – Maintenance
TestEquity 115A-EX Temperature Chamber
Page 8-7
Troubleshooting
SYMPTOM
CONDITION
CAUSES
Does not heat up at all.
1.
If F4 controller light 1A is ON
(F4T left PWR bar is 100%),
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.
Heat is on all the time.
1.
If F4 controller light 1A is OFF
(F4T left PWR bar is 0%).
1.
Solid State Relay SSR1 is
defective (shorted).
Compressors do not run.
1.
If F4 controller light 1B and
DigitalOut 8 are ON (F4T Cool &
Compressor outputs are ON).
1.
Pressure switch PS2 is tripped.
R-404A pressure switch
PS2 trips.
1.
Trips after operating for a while.
1.
Ambient temperature may be
too high (over 90
°
F). Dirty
condenser, inadequate clearance
from back of chamber to the
wall.
Cools down too slow.
1.
Does not meet published
specifications with empty chamber
and ambient temperature is not
over 80
°
F.
1.
Low charge (leak). Solenoid
valve SV1 is defective (doesn’t
close completely).
Does not cool down at all.
1.
Both compressors are running.
1.
Low charge (leak). Plugged
capillary tube.
Temperature varies more
than ±0.5°C or 1°C total.
1.
If PID parameters in temperature
controller were changed.
2.
If PID parameters in temperature
controller are correct and only
occurs in cool mode.
1.
Re-enter values as shipped from
TestEquity.
2.
Solenoid valve SV2 may be
defective (does not completely
seal when cycled off).
Compressors turn on and
off too frequently.
1.
If compressor control parameters
in temperature controller were
changed.
2.
If compressor control parameters
in temperature controller are
correct.
1.
Re-enter values as shipped from
TestEquity.
2.
Solenoid valve SV2 may be
defective (does not completely
seal when cycled off).
Figure 8-1 – PS2 Pressure Switch Reset Button (lower rear panel removed)
