Barnstead 47900 Operation Manual page 42

T
ROUBLESHOOTING
Door switch does
not cut power to
heating elements.
Controller over-temp.
does not cut power
to furnace chamber.
Slow heatup.
Repeated element
burnout.
42
Door switch not functioning.
Alarm output device malfunction. Replace controller.
OTP relay malfunction.
Element shorted to ground.
Low line voltage.
Heavy load in chamber.
Wrong heating element.
Heating element burned
out.
Overheating furnace.
Heating harmful materials.
Contamination from previous
burnout.
Realign or replace door safety
switch.
Replace relay.
Replace faulty element.
Install line of sufficient size
and voltage (isolate furnace
from other electrical loads).
Lighten load in chamber to
allow heat to circulate.
Install proper element.
Replace element.
Keep furnace under maximum
temperature. Closer supervi-
sion of control setting.
Enclose material in container.
Clean up spills in and on
chamber. Ventilate chamber by
leaving top vent slightly open
when heating known harmful
reagents.
Replace insulation material.