ESH150
–3PE~400V
Service manual
48/56
Ref. NR-000144-ENG
Heaters
WARNING!
Before proceeding to any kind of maintenance work, make sure the power
switch is in the OFF position and that the unit is disconnected from the power supply.
Never open the electrical console when the unit is connected to the power supply.
Heaters can reach high temperatures. Always wait until they have cooled down before
handling them.
1. Heating elements
To replace a defective heating element, proceed as follows:
a) Depressurize the unit, disconnect it from the power supply and remove the heater cap.
b) Disconnect the element from the terminal block using the appropriate tool, loosen the
element and remove it from its housing. The element should be smooth and shiny in
appearance. If it is blackened or shows accretions of material, replace it.
c) Check the new element with a tester: the resistance reading should be as shown in
on pag.
d) Apply PTFE or thread-locking compound and screw the element into place in its
housing.
e) Re-connect the cables in the terminal block, make sure the connection is parallel and
replace the heater cap.
NOTE:
If the element to be replaced is the element in contact with the temperature
sensor, first remove the sensor.
2. Temperature sensor
The temperature sensor is secured to the hose coupling with a ferrule and a torque nut. Once
inserted in its housing, the ferrule forms part of the sensor and may not be moved out of
position. Check that the sensor has been correctly inserted before securing it in place with the
torque nut.
a) Depressurize the unit and disconnect it from the power supply. Check that the body of
the coupler inserted in the heater is correctly tightened to prevent leaks.
b) Fit the heating element.
c) Fit the torque nut and ferrule to the sensor and insert the sensor into the body of the
connector until it touches the heating element. Make sure the spring inside the heater is
not impeding contact between the sensor and the element.
d) Secure the sensor and tighten the locking nut.
