Shel lab HF2-2 Installation And Operational Manual page 13

TROUBLESHOOTING
Temperature too high
Display reads "HI" or "400"+
Chamber temp spikes over set point and
then settles to set point
Temperature too low
Display reads "LO"
Unit will not heat over a temperature that
is below set point
Unit will heat up at all
Indicated chamber temperature unstable
TEMPERATURE
1/ controller set too high
2/ controller failed on – call Customer Service
3/ wiring error – call Customer Service
Probe is unplugged, is broken or wire to sensor is broken – trace wire
from display to probe; move wire and watch display to see intermittent
problems
Recalibrate
1/ high limit set too low – see section 4.5
2/ controller set too low
3/ unit not recovered from door opening – wait for display to stop changing
4/ unit not recovered from power failure or being turned off – incubators
will need 24 hours to warm up and stabilize
5/ element failure – call Customer Service
6/ controller failure – confirm with front panel lights that controller is calling
for heat
7/ high limit failure – confirm with front panel lights that High Limit is
operating correctly
8/ wiring problem – check all functions and compare wiring to owners
manual - especially around any areas recently worked on
9/ loose connection – check shadow box for loose connections
1/ sensor is plugged in backwards – call Customer Service
2/ if ambient room temperature is lower than range of unit – compare set
points and ambient temperature to rated specifications in Section 10.0
1/ confirm that blower motor is moving and that amperage and voltage
match data plate – check blower motor motion in shadow box and feel for
air movement in chamber
2/ confirm that set point is set high enough –turn High Limit clockwise and
see if High Limit light comes on
3 / check connections to sensor
4/ check calibration – using independent reference thermometer.
1/ verify that controller is asking for heat by looking for controller light – if
controller light is not on, there is a problem with the controller
2/check amperage – amperage should be virtually at maximum rated
(data plate) amperage
3/ do all controller functions work?
4/ is the High Limit set high enough? – for diagnostics, should be fully
clockwise with the pilot light never on
5/ has the fuse/circuit breaker blown?
1/ ±0.1 may be normal
2/ is blower motor working? – remove top panel and verify movement of
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Section
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