EATON CORPORATION Cutler-Hammer
InformationSheets 70C1486H01
3
4.0 Remote Indicator
Circuit breakers built after July 2006 will be wired with
secondary contacts A12 which is reassigned to
Maintenance Mode Enable. (MM_E) -
(See label on
secondary contacts)
A normally open contact (A10, A11) is
available for customer use via programming of RelayA. This
contact can be used to indicate remotely that the
Maintenance setting is armed. Refer to diagram on page
three for a wiring of this remote (blue light) indicator.
5.0 Choosing the Reduction Setting
The Arc Flash Maintenance Switch has five unique
settings. From the factory, the Magnum circuit breaker is
shipped with the Digitrip unit set to the 2.5x setting and
with its Maintenance Mode disabled. The “Maintenance
Mode Enabled” message provides an indication that the
Maintenance Mode setting is armed per one of the three
methods described in section 3.0.
In general, the selection of one of the Reduction Settings
should be determined and selected by a person who is
experienced in power system analysis.
This setting choice normally does not change unless there
are future system modifications that could increase or
decrease fault levels at the circuit breaker location.
For time/current curve information, refer to drawing
# 70C1498.
6.0 Tripping and Testing
The Maintenance Mode function will provide fast tripping
even when the regular Instantaneous is set to OFF. The
Instantaneous LED position is also used to indicate a trip
initiated by the Maintenance Mode setting. The message
“Maintenance Mode Trip” will be displayed after a trip.
The Maintenance setting, external wiring (if any) and
tripping functionality should all be periodically verified by
primary or secondary injection current testing.
FIGURE 2. Digitrip 1150 with ARMs
