Instruction Manual

LAC Series Oven Owner’s Manual TROUBLESHOOTING
Version 1 39
Copyright © 2012 by Despatch Industries.
All rights reserved. No part of the contents of this manual may be reproduced, copied or transmitted in any form or by any
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Symptom
Possible Cause
Next Step
Oven will
not control
at setpoint
High Limit set too low
Set the High Limit higher.
Protocol 3 controller
malfunction
Replace controller.
SSR malfunction
Replace SSR and/or check control output voltage.
Air friction of recirculation
fan
Open exhaust air vent. Unit will not control below
minimum operating temperature with vent closed.
Heater
does not
shut down
until temp.
reaches the
High Limit
setting
Protocol 3 controller
malfunction
Replace Protocol 3 controller.
SSR malfunction
Replace SSR.
Table 3. Troubleshooting with Control Panel Mounted Circuit Board.
If LED is…
Check…
1 LED
2LED
3 LED
Not Lit
Check Fuse Block 2F and 3F (Figure 14)
Lit
Not lit
Lit
 Check High Limit
 Check optional door switch, if appropriate
Lit
Lit
Lit
 Check Fuse Block 1F and 4F (Figure 14)
 Check SSR
 Check heater
 Check heater relays
Danger!
Table 3 lists troubleshooting steps that must be performed by a
qualified electrician or electrical technician trained on electrical
safety and the use of personal protective equipment.
Figure 14. LAC-7 Circuit Board.