Megger MOM2, Руководство пользователя

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BD0333FE ZP-BD03E MOM2 33
6 APPLICATION EXAMPLES
6.3 Test a CB using
DualGround
you can perform testing with both sides grounded.
However the measurement accuracy will be some-
what lower with both sides grounded depending on
the ratio of the currents – circuit breaker / grounding
cables (see section 2.2). This example shows a test on
a HV CB using a man lift.
1]
The circuit breaker shall be disconnected,
closed and grounded on both sides.
2]
Attach the black (3 m) test cable with Kelvin
clamp and the Kelvin probe with trigger to
the instrument.
3]
Hook the MOM2 to your belt or use the strap
to hang it around your neck.
4]
Attach the black test cable with Kelvin clamp
to one side of the CB using the man lift.
5]
Move yourself to the other side of the CB us-
ing the manlift.
6]
Press and hold the Kelvin probe to the test
object and pull the trigger.
Measurement on CB with both sides grounded.
Note The test can also be done by using two Kelvin
clamps.
6.4 Test a CB by injecting
through the ground cables
1]
The circuit breaker (CB) shall be disconnect-
ed, closed and grounded on both sides.
2]
Connect the MOM2 to ground.
3]
Attach an extra ground cable (not included)
with at least 95 mm
2
cross section area to one
side of the CB.
4]
Connect the 0.5 m current cable to the cur-
rent out minus terminal on the MOM2 and
attach the other end to ground close to
where the CB's grounding cable is attached.
(the opposite side of CB from where the ex-
tra ground cable is attached).
5]
Mount the 0.1 m plate to the current out
plus terminal on the MOM2 and attach the
extra ground cable to the plate.
6]
Connect the sensing cables (red and black) to
the CB.
7]
Remove the original CB grounding cable on
the side where the extra grounding cable is
attached.
8]
Press the TEST button.
Traditional measurement from ground. Injection is done
through existing grounding cable (earthing). Optional cable
kit is needed. Available kits have 5, 10 or 15 m cables.
Disconnection
1]
Re-attach the original CB grounding on the
side where the extra grounding is attached.
2]
Disconnect the sensing cables from the CB.
3]
Disconnect the extra ground cable from the
0.1 m plate on plus terminal.
4]
Disconnect the 0.5 m current cable from
ground.
5]
Disconnect the ground cable from MOM2.