THERMOJET
®
H-2500E SERIES
OIL PURIFIER SYSTEM
INSTALLATION AND OPERATING MANUAL
Doc #
77740119
Rev
15
Date
June 2020
Page
65
of
100
Verify Oil Heater High Temperature Cutout Operation
To perform this maintenance task, the ThermoJet Oil Purifier must be running and operating normally. This
maintenance task is performed to ensure safe operation should a high temperature condition occur. For
additional information regarding the operation of the high temperature circuit see drawings and schematics
in section of this manual titled IX PARTS LIST / DRAWINGS / SCHEMATICS.
The oil heater is equipped a thermocouples for high temperature protection. The thermocouple is clamped
to the outside of the heater vessel. This thermocouple provides a signal for a high temperature alarm and
cutout for the heater vessel surface.
Should the heater vessel surface thermocouple output reach the high temperature alarm/heater cutout
setting, power to the oil heater element is interrupted. When this happens the oil temperature as indicated
on the heater controller display will begin to decrease. As the oil temperature falls below oil heater
controller setting, the heater control thermocouple will sense the decreasing oil temperature and signal the
oil heater temperature controller to energize the heater. However the high limit controller will prohibit the oil
heater from energizing and oil temperature will continue to fall. The Heater On pilot light will be illuminated
because the heater controller is providing an ON signal to the heater power control relay.
NOTICE:
When a Heater High Temperature alarm occurs the red
pilot light will illuminate. The alarm pilot light will remain
illuminated and the oil heater will not be operable until the
Heater High Temperature reset button is depressed. Press
the reset push button to resume heater operation.
High temperature pilot light (red)
/ manual high limit reset
T/C clamped to outside of heater
vessel
Heater ON pilot light (amber)
