Effective 7/1/2003
Page 7
I.L. 70C1037H04
1.4 Wiring
The internal components of the breaker, and how they are
wired out to the breaker secondary contacts, are shown in
the breaker master connection diagram provided as
Appendix C.
1.5 Plexiglass Cover
A clear, tamper-proof, plexiglass door sits on the breaker
cover. This door allows the settings to be viewed but not
changed, except by authorized personnel. The plexiglass
cover meets applicable tamper-proof requirements. The
cover is held in place by two cover screws. Security is
insured by the insertion of a standard meter seal through
the holes in both of the cover retention screws. The
plexiglass cover has an access hole for the Step and
Reset/Battery test pushbuttons.
1.6 Ground Alarm/Power Supply Module (520M/MC Models only)
The Ground Alarm/Power Supply Module
(See Figure 1.4)
is an optional accessory for the Digitrip 520M, 520M
i
and
is a required accessory to enable communications on the
Digitrip 520MC and 520MC
i
models. The module can be
installed beneath the metal mounting plate of the trip unit
in the Magnum Circuit Breaker. The module covers the
following input voltage ratings: 120 VAC (7802C83G01),
230 VAC (7802C83G02), and 24-48 VDC (7802C82G01).
The burden of the Power/Relay Module is 10VA.
1.6.1 Auxiliary Power
When the module is wired as shown in Figure 1.5, it will
provide an auxiliary power supply so that the 520M/520M
i
or 520MC/520MC
i
liquid crystal display (LCD) will be
functional even when the circuit breaker has no load. A
Digitrip 520M or 520MC tripunit
without
auxiliary power
will not display data until load current reaches approxi-
mately 30% 1 phase or 10% 3 phase of the
(I
n) rating.
1.6.2 Ground Alarm
A second function of the module is to provide either a
ground trip or ground alarm only output contact via the
relay supplied in the module. On Digitrip 520M/520MC with
ground fault protection, an LED on the front of the unit also
provides an indication of ground fault trip.
1.6.3 Ground Fault Trip
When the Ground Alarm/Power Supply module is used
with the MLSIG model, this unit will provide ground fault
trip contacts when the circuit breaker trips on a ground
fault. You must then push the Reset button on the Digitrip
in order to reset the contacts
(See Figure 1.5, Note 3)
.
Figure 1.4 Ground Alarm/Power Supply Module for the
520M or 520MC Trip Units
1.6.4 Ground Fault Alarm
A ground fault alarm alerts a user to a ground fault condi-
tion without tripping the circuit breaker. A red Alarm Only
LED on the front of the trip unit will indicate the presence
of a ground fault condition that exceeds the programmed
setting.
The ground fault alarm relay is energized when the ground
current continuously exceeds the ground fault pickup
setting for a time in excess of a 0.1 second delay. The
alarm relay will reset automatically if the ground current is
less than the ground fault pickup
(See Figure 1.5, Note 4).
1.6.5 High Load Alarm (520M/520MC Models only)
The Digitrip 520M and 520MC models of the LSI style only,
(Figures 3.3.1 and 3.4.1), the module shown in Figures
1.4 and 1.5 will provide a HighLoad Alarm contact instead
of the Ground Alarm function when wired to the breaker
secondary contacts A-10 and A-11. The function activates
after a 1 second time delay when any phase current
exceeds 85% of the Ir setting
.
