COMPONENT INSPECTED
PROCEDURE
POSITIVE CHECK
1
Insulation resistance
Medium voltage circuit
Using a 2500 V Megger, measure insulation resistance between
phases and earth of circuit.
The insulation resistance should be at least 50
Mohm and in any case, constant over time.
Auxiliary circuits
Using a 500 V Megger (installed equipment permitting), measure
insulation resistance between auxiliary circuits and earth.
The insulation resistance should be a few Mohm
and, in any case, constant over time.
2
Auxiliary circuits.
Make sure that connections to control circuit are correct: proceed
with relative power supply.
Operations and signals are normal.
3
Manual operating
mechanism.
Perform a few closing and opening operations (see chap. 6).
NOTE. Supply undervoltage release and locking magnet on
operating mechanism at the relative rated voltage (if applicable).
The operations and relative signals take place
correctly.
4
Motor operator
(if applicable).
Supply spring loading gearmotor at the relative rated voltage.
Spring is loaded correctly.
Signals are normal.
Gearmotor stops when springs have been loaded.
Perform a few closing and opening operations.
NOTE. Supply undervoltage release and locking magnet on
operating mechanism at the relative rated voltage (if applicable).
Gearmotor reloads springs after each closing
operation.
5
Undervoltage release
(if provided).
Supply undervoltage release at relative rated voltage and perform
circuit-breaker closing operation.
Circuit-breaker closes correctly.
Signals are normal.
Disconnect release from voltage supply.
Circuit-breaker opens.
Signal changes over.
6
Shunt opening release and
additional shunt opening
release (if provided).
Close circuit-breaker and supply shunt opening release at relative
rated voltage.
Circuit-breaker opens correctly.
Signals are normal.
7
Shunt closing release
(if provided).
Open circuit-breaker and supply shunt closing release at relative
rated voltage.
Circuit-breaker closes correctly.
Signals are normal.
8
Key lock (if applicable)
Open circuit-breaker, press and hold opening pushbutton, then
turn key and remove it from its seat.
Attempt circuit-breaker closing operation.
Neither manual nor electric closing takes place.
Insert key again and turn it through 90°.
Perform closing operation.
Both electrical and manual closing take place
correctly; in this position the key cannot be
removed.
9
Locking electromagnet
(-RLE1) (if applicable).
Attempt to close circuit-breaker both manually and electrically with
circuit-breaker open, spring loaded and locking electromagnet
de-energized.
Closing fails to occur.
10
Auxiliary contacts in
operating mechanism.
Connect auxiliary contacts to suitable signaling circuits.
Perform a few closing and opening operations.
Signaling occurs normally.
11
Locking electromagnet on
circuit-breaker truck (-RLE2)
(if applicable).
Attempt to rack-in circuit-breaker with circuit-breaker open, in
isolated for test position and locking electromagnet de-energized.
Racking-in fails to occur.
Energize locking electromagnet and perform racking-in operation.
Racking-in occurs correctly.
12
Transmitted auxiliary
contacts for signaling circuit-
breaker connected,
disconnected (UniGear
switchgear or PowerCube
modules).
Connect auxiliary contacts to suitable signaling circuits.
With circuit-breaker racked-in to enclosure, perform a few
operations from isolated for test position to connected position.
Move circuit-breaker to withdrawn position..
Signals due to the operations occur normally.
T3
M ED I U M VO LTAG E PRO D U C T S
31
