Troubleshooting - Barnstead FB1300 Operation And Repair Manual And Parts List

The Troubleshooting section is intended to aid in defining and correcting possible furnace
problems. When using the chart, select the problem category that resembles the malfunc-
tion. Then proceed to the possible causes category and take necessary corrective action.
Problem
The furnace does not heat
(CYCLE light does not illuminate).
Door switches do not cut
power to heating elements.
Slow heatup.
Repeated element burnout.
Inaccurate temperature
readout.

Troubleshooting

Possible Causes
No power.
Defective electrical hookup.
Thermocouple has oxidized and
opened the circuit. (Open thermocouple
is indicated on the display as a
temperature of 0-5 degrees).
Controller malfunction.
Door switches malfunction.
Defective solid state relay.
Door switches are not functioning.
Low line voltage.
Heavy load in chamber.
Wrong heating element.
Overheating furnace.
Heating harmful materials.
Contamination present from
pervious burnout.
Oxidized or contaminated
thermocouple.
Poor thermocouple connection.
Improper loading procedures.
Poor ventilation of base.
Thermocouple connections
reversed. (Indicated by
downscaling or temperature on
display.)
Controller malfunction.
Corrective Action
Check power source and fuses or
breakers.
Repair electrical hookup.
Replace thermocouple.
Replace controller.
Re-align or replace door safety switches.
Replace output relay.
Re-align or replace door switches.
Install line of sufficient size and proper
voltage. (Isolate furnace from other
electrical loads.)
Lighten load in chamber to allow
heat to circulate.
Install proper element.
Keep furnace under maximum
temperature.
Enclose material in container. Clean up
spills in and on chamber. Ventilate
chamber by opening door slightly when
heating known harmful reagents.
Replace insulation material.
Replace thermocouple.
Tighten connections.
Use proper loading procedures.
Clear area around furnace base.
Reconnect thermocouple correctly.
Replace controller.
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