Shellab SCO10W-2 - Manual (Page 20)

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and see if heating light or safety light comes on
3/ check connections to sensor
4/ check calibration
– using independent certified reference
thermometer, follow instructions in sections 5.4 and 5.8
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 fan working?
– remove top panel and verify movement of cooling
fan in center of shadow box
3/ is ambient room temperature radically changing
– either door opening
or room airflow from heaters or air conditioning? – stabilize ambient
conditions
4/ sensor miss-located, damaged, or wires may be damaged - check
mounts for control and OTP sensors, then trace wires between sensors
and controls
5/ calibration sensitivity
– call Customer Service
6/ OTP set too low – be sure that OTP set point is more than 5 degrees
over desired Main set point; check if OTP pilot is on continuously; turn
controller knob completely clockwise to see if problem solved then follow
instructions in section 5.8.E for correct setting.
7/ electrical noise
– remove nearby sources of RFI including motors,
arcing relays or radio transmitters
8/ bad connection on temperature sensor or faulty sensor
– check
connectors for continuity and mechanical soundness while watching
display for erratic behavior; check sensor and wiring for mechanical
damage
9/ bad connections or faulty capacitor
– check connectors for
mechanical soundness and look for corrosion around terminals or signs
of arcing or other visible deterioration
Will not maintain set point
1/ assure that set point is at least 5 degrees over ambient room
temperature
2/ see if ambient is fluctuating
Display and reference thermometer don’t
match
1/ calibration error – see section 5.4
2/ temperature sensor failure – evaluate if pilot light is operating
correctly
3/ controller failure
– evaluate if pilot light is operating correctly
4/ allow at least two hours to stabilize
5/ verify that reference thermometer is certified
Can't adjust set points or calibration
1/ turn entire unit off and on to reset
2/ if repeatedly happens, call Customer Service
Calibrated at one temperature, but not at
another
This can be a normal condition when operating temperature varies
widely. For maximum accuracy, calibration should be done at or as
close to the set point temperature.