Page 64
LATCH LEVER
SWITCH
!£VER
OVERCURRENT
Tll!P
lNO!CAT!ON SWITCH
Fig. 69 Overcurrent Trip Switch (390239)
Three contact arrangements are available as standard:
(1) two normally open, (2) two normally closed,
or
(3) one
normally open and one normally closed contact. These
are independently wired to secondary disconnect con-
tacts
at
the rear
of
the breaker unit. Some special units
may have one
or
two additional contacts.
The device is latch-type and must be manually reset by
means
of
a pushbutton on the breaker front panel. Also
available is an electric reset for remote operation. Fig-
ures 69 and 70 illustrate an electric reset device.
8.7.3
High
Load
Switch
(available
with
Amptector
1-A
only)
This is a self-resetting solid-state device which picks up
on an overload condition
at
a lower pick-up value than
the breaker overload trip setting
of
the Amptector trip
unit. Its function is to give advance notice
of
an overload
condition before the breaker trips. See Figure 71.
The pick-up point
is
adjustable from 60% to 100%
of
the
Amptector trip long delay pick-up setting. The non-adjust-
able time delay
of
60 seconds requires that the pick-up cur-
rent be maintained for that interval to cause the relay
contact to operate.
If
the load current falls below the
pick-up point, the timing resets
in
about a second. The
relay has one normally open and one normally closed con-
tact with a common connection. Its built-in power supply
1.8. 33-790-11
requires a reliable sinusoidal source
of
either 120
or
240
volts AC.
ACTUATOR
CAM
OVERCURRENT
TRIP
INDICATION
POSITION
--==\
Fig.
70
Overcurrent Trip Switch Operation
Fig.
71
High Load Switch (391087)
Effective October 1998
Courtesy of NationalSwitchgear.com
To Next Page
Loading...
