7
XT7 mechanical control
Lubricate the shafts and the
opening latches with grease type
MOBILGREASE 28 (EXXON
MOBIL) (Fig. 3);
8
Reinstall all parts and, if necessary, reconnect the auxiliary power supply
XT7: using the various auxiliaries in succession, perform 10 each of the following operations::
- Opening
- Closing
- Releasing with the trip test
- Resetting
XT7M: 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
For XT7M, check the procedures in the following sequence:
- Open - springs unloaded
- Open - springs loaded
- Closed - springs unloaded
- Closed - springs loaded
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Check the efficient operation of the devices for locking the circuit breaker in its inserted or withdrawn positions, if any.
Interlocks
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 Their efficiency cannot be tested while the breakers are in the Test or Withdrawn positions.
Withdrawable circuit breakers
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has been withdrawn.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 device for locking the circuit breaker in its open position (with a key or padlock), if any.
Inspection of electrical and mechanical accessories
Check the accessories:
1. Check that the accessories are securely fixed to the circuit-breaker.
2. Check that the accessories are connected correctly to the circuit-breaker.
3. Make sure that the coils (YU-YO-YC), if present, are in good condition (no excessive wear and tear, overheating, rupture).
4. Make sure that the mechanical operation counter functions correctly (if present) by operating the circuit-breaker.
5. Check the wear on the brushes of the gearmotor and if necessary replace them.
NOTE: it is advisable to replace the gear motor if it has performed more than 10000 spring charging operations or reached 50% of the declared
mechanical life of the circuit-breaker.
Inspection of the protection trip unit
Check that the trip unit is in good condition:
1. Power the protection trip unit with an Ekip TT battery unit.
2. Check the correct operation of the protection trip unit: tripping test with "Trip Test" and "Autotest".
3. With an Ekip Dip trip unit verify the absence of alarms through frontal LEDs.
4. With an Ekip Touch trip unit, verify the absence of alarms via the display and the front LEDs.
5. Make sure that the cables are correctly connected to the modules and to the trip unit (if applicable).
6. On an Ekip Touch trip unit check the percentage of wear on the contacts of the circuit-breaker.
7. Finally, remove the Ekip TT battery unit.
Fig. 3
Servicing procedures
Servicing procedures; final checks