Check the efficient operation of any accessories.
Check the efficient operation of the geared motor, if any
Check the proper operation of the undervoltage release, if any.
Check the efficient operation of the shunt opening release, if any.
Check the efficient operation of the shunt closing release, if any.
Check the efficient operation of the circuit breaker's auxiliary contacts, if any.
Check the efficient operation of the device for locking the circuit breaker in its open position (with a key or padlock), if any.
Safety release
Check the efficient operation of the safety release: test the release using the Trip Test and the Autotest, where applicable.
reinstall all parts and, if necessary, reconnect the auxiliary power supply
T7M-X1: using the various auxiliaries in succession, perform 10 each of the following operations:
- opening (both locally and remotely, where applicable)
- closing (both locally and remotely, where applicable)
- releasing by means of a trip test from the relay
T7: using the various auxiliaries in succession, perform 10 each of the following operations:
- opening
- closing
- releasing with the trip test
- resetting
For T7M-X1, check the procedures in the following sequence:
- open - springs unloaded
- open - springs loaded
- closed - springs unloaded
- closed - springs loaded
Interlocks
Withdrawable circuit breakers
Check the proper installation and efficient operation of the interlocking devices between circuit breakers placed side by side
or one above the other (if any). Their efficiency cannot be tested while the breakers are in the Test or Withdrawn positions.
In the withdrawable versions, check the efficiency of the mechanics for inserting and withdrawing the circuit breaker from
the fixed part of the device, completing the movement by means of the lever provided and making sure that the shutters
for segregating the live parts close when the breaker has been withdrawn.
Check the efficient operation of the devices for locking the circuit breaker in its inserted or withdrawn positions, if any.
Servicing procedures; final checks:
If necessary, refer to the instructions given with the circuit breaker and with the accessories, which are also available on the
website http:\\bol.it.abb.com
T7 mechanical control
Lubricate the shafts and the
opening latches with grease type
MOBILGREASE 28 (EXXON
MOBIL) (Fig. 3);
Fig. 3
Consult ABB SACE for replacement of the protection release on the LTT low temperature version of Tmax T7.
