Connection and commissioning
5.5 Commissioning
3VA27 molded case circuit breakers & 3WL10 air circuit breakers
190
Manual, 10/2018, L1V30499596002-01
The following table describes the general testing of the circuit breaker and its installed
environment:
Items to be tested
1)
Checks
Switchboard
1. Sufficient ventilation to avoid overtemperatures
2. Clean installation location, free of all installation waste (e.g. cables,
tools, metal splinters)
3. Circuit breaker correctly mounted (tightening torques and ventilation
clearances observed)
4. The environmental conditions of the installation must match the
specifications (see Chapter Application planning (Page 137)).
Connections
1. Electrical connections at the terminals of the circuit breaker tighte-
ned
2. Cables, busbars, and auxiliary current wiring have sufficient
conductor cross sections
3. Required insulation clearances between the phases (if necessary
with phase barriers) and from phases to the switchboard panel.
Operations
Perform a few open and close operations.
It must be possible to operate the lever of the operator normally and to
charge the spring energy store.
Note: If an undervoltage coil is present, the circuit breaker can only be
closed when a voltage is applied at the corresponding auxiliary
conductor terminals.
1)
If present
The following tests must be conducted for inspection before re-commissioning after tripping
and after lengthy storage under certain environmental conditions. These can be performed
with a TD310 test device to power the ETU. They are not mandatory for a device from the
factory because the circuit breaker is completely and thoroughly tested, including all installed
accessories, before delivery. A trip test confirms correct mechanical functioning of the
tripping plunger on the trip coil, actuated by the ETU. Electronic monitoring of the entire
connection between the current transformers, ETU, and trip coil is performed continuously by
the electronics itself (watchdog).
Items to be tested
1)
Checks
Enable alarms
Connect the ETU to a test device and check that no alarms are
present.
Status of the circuit breaker
On the ETUs of the 3-series, the status of the circuit breaker must not
be incorrect (see tables of the LED display in Chapter Alarms
(Page 203)). Perform a close/open operation on the circuit breaker
and check that no alarms have occurred.
On the ETUs of the 6-series, the status of the circuit breaker must be
correctly shown on the display. Perform a close/open operation on the
circuit breaker and check that the change in circuit breaker status is
correctly displayed.
Trip test
Make a trip attempt with the circuit breaker closed during an idle peri-
od (without circulating currents of the mains connection) and check
that the circuit breaker opens.
1)
If present