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4.12 Thermal relay calibration
Depending on the burner type, there are two different thermal re-
lays:
–
Electro-mechanical termal relay (used for single phase motors)
–
Electronic thermal relay (used for three phase motors)
4.12.1 Electro-mechanical thermal relay
The electro-mechanical termal relay (Fig. 23) is used to avoid dam-
age to the motor owing to a strong increase in absorption or the
lack of a phase.
For the calibration, refer to the table given in electrical layout. If the
minimum value of the scale of the thermal relay is greater than the
rating absorption of the motor, protection is still ensured.
This arises when the power supply of the motor is a nominal value.
To reset, in the case of an intervention of the thermal relay,
press the button "RESET" (Fig. 23).
The button "STOP" (Fig. 23) opens the NC (95-96) contact
and stops the motor.
D9273
To test the thermal relay, insert a screwdriver in the window
"TEST" (Fig. 24) and move it in the sense of the arrow
(towards right).
Automatic resetting can be dangerous.
This action is not provided for the burner oper-
ation.
WARNING
D9274
Installation
4.12.2 Electronic thermal relay
To reset, in the case of an intervention of the thermal relay,
press the button "RESET" (Fig. 25).
There are two different solution to test the electronic thermal relay:
Device test (Fig. 26)
Push slowly the button in the window with a little screwdriver.
Fig. 23
Contact test NC (95-96) and NO (97-98)(Fig. 27)
Insert in the window a little screwdriver and move it in the
sense of the arrow.
Fig. 24
25
GB
S8109
Fig. 25
S8111
S8111
Fig. 26
S8110
Fig. 27
20069791
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