Specifications

Thermolators use mercury displacement heater contactors.
The heater contactors should be replaced if:
● You have checked the amp draw on each of the three-phase
legs and discovered a voltage imbalance greater than 10%.
● You have checked the continuity and found that ohms at
the coil equal zero.
To replace the heater contactor:
Disconnect and lockout the main power.
Open the electrical enclosure door.
Turn the
screw on the front panel counterclockwise to open.
Disconnect the wires from the heater contactor
contactor.
Make sure you label the wires to ensure you
can connect them correctly to the new contactor.
Remove the contactor
by removing the screws that
hold it in place.
Discard the old contac-
tor using the proper
disposal procedure.
See
Material Safety Data Sheet
#7439-97 in the
APPENDIX .
Reverse this procedure
to install the new con-
tactor.
Make sure the wires
are connected correctly
.
Thermolator TW-1 and TW-2 UGH015/0100
6-16 TROUBLESHOOTING
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2
3
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WARNING: Hazardous Substance
Thermolators use mercury displacement contac-
tors. Mercury is considered a hazardous substance
and must be dealt with accordingly. See Material
Safety Data Sheet #7439-97-6 for information on
the how to avoid the potential hazards and how to
clean up and dispose of mercury if it spills.
IMPORTANT: Always
refer to the wiring dia-
grams that came with
your Thermolator to
locate specific electrical
components. Illustrations
in the User Guide are
intended to be represen-
tative only.
WARNING:
Electrical Shock Hazard
Only qualified service personnel who have been
trained on electrical testing and the procedures for
avoiding the hazards should diagnose or correct prob-
lems that require opening the unit with power on.
6
REPLACING THE
HEATER
CONTACTOR
Heater contactor