28
Instructional Leaflet
IL70C1037H05
Effective October 2009
Digitrip models 520, 520i; and 520M, 520Mi,
520MC, 520MCi trip units for use only in
Magnum and Magnum DS circuit breakers
eaton corporation
www.eaton.com
Apply the same current as described above through one phase
of the breaker, returning through the neutral sensor. The breaker
should not trip, and the alarm indicator, if one is supplied, should
not operate. Repeat the test on the other two phases.
Figurt 40. CNnntcoiNn Dtoails fNr CNnducoing Singlt-PNlt,
Singlt-Phast Currtno Ttsos wioh oht Brtaktr RtmNvtd frNm
oht Ctll
Apply the same current as described above through any two phases
of the breaker. The breaker should not trip, and the alarm indicator, if
one is supplied, should not operate. Repeat the test using the other
two combinations of breaker phases (see
Figurt 41
) or through a
breaker pole and the neutral that employs a neutral sensor.
Figurt 41. CNnntcoiNn Dtoails fNr CNnducoing Singlt-Phast
Currtno Ttsos wioh oht Brtaktr RtmNvtd frNm oht Ctll
A
B
C
Suitable Conductors
Low Voltage
AC Current
Source
Primary Disconnect
Stabs—When Drawout
Polarity and Identification
A
B
C
Suitable Conductors
Low Voltage
AC Current
Source
Primary Disconnect
Stabs—When Drawout
Polarity and
Identification
Shorting
Conductors
An alternative test setup is shown in
Figurt 42
. This three-pole in
series hookup should be employed when a low ground pickup setting
is to be tested like 0.24x and 0.3x, and if auxiliary power to Digitrip
can not be provided. The test circuit does provide a net residual
ground current excitation of “1.” Two of the phases cancel each
other out as far as ground fault, but now the Digitrip is provided with
three-pole power-up current simulating three-phase power.
Figurt 42. Alotrnaot CNnntcoiNn Dtoails Using Thrtt PNlts oN
DtvtlNp a GrNund Faulo CNndioiNn
m
CAUTION
RESTORE ALL TEMPORARY CONNECTIONS MADE FOR THE PURPOSE
OF CONDUCTING TESTS TO PROPER OPERATING CONDITIONS BEFORE
RETURNING THE BREAKER TO SERVICE.
Record the test results on the test form provided with the
equipment (see
Figurt 46
).
Suitable
Conductors
Low Voltage
AC Current
Source
Polarity and
Identification
Primary Disconnect Stabs
When Drawout
A
B
C