Shellab SSI3-2 - Manual (Page 10)

10
TROUBLESHOOTING
TEMPERATURE
Temperature too high-display and
reference thermometer don’t match
1/ Controller set too high-see section 5.5.
2/ Controller failed on
– call Customer Service.
3/ Wiring error – call Customer Service.
Display reads "HI"
Probe is defective, unplugged, or the wire is broken – trace wire from
display to probe; move wire and watch display to see intermittent
problems.
Chamber temperature spikes over set
point and then settles to set point
Recalibrate – see section 5.6.
Temperature too low-display and
reference thermometer don’t match
1/ OTP set too low – turn OTP fully clockwise.
2/ Controller set too low – see Section 5.5.
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
– see if heating light is on; compare current draw to
data plate.
6/ controller failure
– confirm with front panel lights that controller is
calling for heat
7/ OTP failure
– confirm with front panel lights that OTP is operating
correctly.
8/ Loose connection
– check shadow box for loose connections.
Display reads "LO"
Sensor is plugged in backwards – reverse sensor wires to controller.
Unit will not heat over a temperature that
is below set point
1/ Confirm that amperage and voltage match data plate
2/ Confirm that set point is set high enough
–turn OTP all the way
clockwise and see if heating light or safety light comes on.
3/ Check calibration
– using independent thermometer, follow
instructions in section 5.6.
Unit will not heat up at all
1/ Verify that controller is asking for heat by looking for controller light –
if pilot light is not on continuously during initial start up, 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 OTP set high enough?
– for diagnostics, should be fully
clockwise with the pilot light never on.
5/ Has the fuse/circuit breaker blown?
Indicated chamber temperature unstable
1/ ±0.1 may be normal.
2/ Is ambient radically changing
– either door opening or room airflow
from heaters or air conditioning ? – stabilize ambient conditions.
Section
7