GE AKR-30 Series Maintenance Manual page 25

When adjusting the pick up level on instantaneous de
undervoltage devices, set the gap between the armature
.030
and magnet to inches using the adjustment screw
shown in Fig. 32C. After setting the pick up level, use this
same adjustment screw to obtain the drop out setting.
Cover the adjustment screw locknut with
4. When this device is installed or replaced, i
ability to trip the breaker must be demonstrated.
ADJUSTMENT
FIG. 32C - CLOSED GAP C H ECK
Undervoltage devices trip the breaker when the armature
opens. This causes an extension on the armature to strike
the paddle on the trip shaft. An extension of the other end
of the armature. When the armature is released, this exten­
sion stops against a stop which is factory set. To check
positive trip, the armature should be held down, the end of a
1 132-inch diameter wire should be inserted against the stop,
and the armature released. If this trips the breaker, the set­
ting is correct. The place to insert the wire is shown in Fig.
320.
Note that only the tip of the wire is to be against the
stop.
If the undervoltage device does not have positive tripping
ability, the adjustment screw of the trip paddle assembly on
the trip shaft may turned in increments of half turns until
be
the check is successful.
When the undervoltage device is closed and the breaker
mechanism is reset, there must be clearance between the
trip paddle and the device armature.
7.9
STATIC TIME·DELAY UNDERVOLTAGE
The time-delay undervoltage system consists of a
static
controls an
time-delay unit which
The time-delay unit is
voltage device.
s i e the undervoltage
in the w tchg ar and
on Table S lists the catalog numbers available.
the breaker.
CAT. NO.
G- & '
TAKYUVT- 1
TAKYUVT-2
G-
TAKYUVT- 3
RTV.
tS
positive
instantaneous under­
separately mounted
mounted
device is
TABLE 5
CONTROL
VOLTAGE
TERMINALS
1 & 2
voc
125
r=;c\ 250VDC
208/240 VAC
INSERT
WIRE
as
GAGE
320
FIG.
a-c
If the control voltage is any voltage other than
2081240V
ac, a control power transformer (also remotely
mounted with respect to the breake" must be used. This
must have a minimum rating of
When installed, the voltage to be monitored is connected
across terminals No. 1 and No.
The coil of the tripping unit is connected across terminals
4 and No. 5 of the static
No.
disconnects of the breaker. The secondary disconnects to
be used will be shown on the breaker wiring diagram.
No more than one undervoltage tripping device should
be used in conjunction with one static time-delay unit.
The static time-delay undervoltage can also be furnished
with a thermotector control unit. Overheating of motor win­
dings causes the thermotector, imbedded in the motor win­
dings, to open. This de-energizes the undervoltage device
on the breaker and drops the motor load.
7.9.1 ADJUSTMENTS
In the event the system fails, the following checks
recommended to determine whether the undervoltage
device on the breaker of the static time delay unit is the
faulty component.
1 . Check input voltages across terminals 1 and
static Table
box. See
2.
Check output voltages on terminals
undervoltage device connected.
TI M E-DELAY U NITS
APPROXIMATE STEADY STATE
OPERATING VOLTAGE
DC
TERMINALS
4 & 5
50
100
1 10/125
- POSITIVE TRIP CHECK
100
volt-amperes.
2 of the static delay
box through the secondary
5 for these values.
4 and
Table 5 for values.
See
NOMINAL DC COIL
RESISTANCE
(OHMS)
@ 25°C
440
1600
1600
box.
are
2 on
the
5 with the
25