Shellab SVAC4-2 - Manual (Page 15)

15
TROUBLESHOOTING AND SERVICE
TEMPERATURE
Temperature too high
1/ controller set too high
2/ controller failed on
–call Customer Service
3/ wiring error –call Customer Service
Display reads "HI" or "400"+
probe is unplugged, is broken or wire to sensor is broken –call Customer
Service
Chamber temperature spikes over
set point and then settles to set
point
Recalibrate to desired temperature set point
Temperature too low
1/ Set Over Temperature too low
2/ Main control 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
5/ element failure
– see if Heating light is on
6/ Main controller failure – confirm with front panel lights that controller is
calling for heat
7/ Set Over Temperature failure
– confirm with front panel lights Set Over
Temperature is operating correctly
8/ wiring problem
–check all functions. If not solved-call Customer Service
Display reads "LO"
1/ if ambient room temperature is lower than range of unit –compare set points
and ambient temperature to rated specifications in section 9.0, Unit
Specifications.
2/ Main sensor is plugged in backwards
–call Customer Service.
Unit will not heat over a temperature
that is below set point
1/ confirm that Set Over Temperature Control set point is set above the Main
Temperature set point.
2/ check calibration
–using independent thermometer
Unit will not heat up at all
1/ verify that controller is asking for heat by looking for Heating light –if pilot
light is not on continuously during initial start up, there is a problem with the
controller-call Customer Service.
2/ do all controller functions work?
3/ is the Set Over Temperature Control set high enough?
–for diagnostics,
should be fully clockwise with the Over Temperature light never on
4/ has the fuse blown? Check fuse at inlet.
5/ Units will need at least some vacuum in chamber to keep unit air tight-verify
with Vacuum Gauge is above “0”.
Indicated chamber temperature
unstable
1/ ± 1. may be normal.
2/ is ambient room temperature radically changing
–either door opening or
room airflow from heaters or air conditioning ? –stabilize ambient conditions.
3/ calibration sensitivity –call Customer Service.
Section 9