Static Time-Delay Undervoltage - GE AKR-30 Series Maintenance Manual

OPEN GAP
ADJUSTM ENT
FIG. 328 - OPEN GAP CHECK
ADJUSTMENT
FIG. 32C - CLOSED GAP CHECK
7.9 STATIC TIM E-DELAY U N DERVOLTAGE
The static time-delay undervoltage system consists of a
time-delay unit which controls an i nstantaneous under­
voltage device. The time-delay unit is separately mounted
in the switchgear and the undervoltage device is mounted
on the breaker. Table 5 1ists the catalog n umbers available.
If the a-c control voltage is any voltage other than
208/240V ac, a control power transformer (also remotely
mounted with respect to the breaker) m ust be used. This
must have a minimum rating of 100 volt-amperes.
CAT. NO.
TAKYUVT-1
TAKYUVT-2
TAKYUVT-3
INSERT WIR E
G A GE
across term inals No. 1 and No. 2 of the static delay box.
The coil of the tripping unit is connected across terminals
No. 4 and No. 5 of the static box through the secondary
disconnects of the breaker. The secondary disconnects to
be used will be shown on the breaker wiring diagram.
be used i n conjunction with one static time-delay unit.
with a thermotector control unit. Overheating of motor win­
dings causes the thermotector, imbedded in the motor win­
d ings, to open. This de-energizes the undervoltage device
on the breaker and drops the motor load.
7.9.1 ADJUSTM ENTS
recom mended to determi ne whether the undervoltage
device on the breaker of the static time delay unit is the
faulty component.
static box. See Table 5 for these values.
undervoltage device connected. See Table 5 for values.
TAB L E 5 TIM E-DELAY U N ITS
CONTROL APPROXIMATE STEADY STATE
VOLTAGE DC OPERATING VOLTAGE
TERMINALS
1 & 2
1 25 VDC
250VDC
208/240 VAC
-
FIG. 320 POSITIVE TRIP CHECK
When installed, the voltage to be monitored is connected
No more than one undervoltage tripping device should
The static time-delay undervoltage can also be furnished
In the event the system fails, the following checks are
1. Check input voltages across terminals 1 and 2 on the
2. Check output voltages on terminals 4 and 5 with the
TERMINALS
4 & 5
50
1 00
1 1 0/ 1 25
NOMINAL DC COIL
RESISTANCE
(OHMS)
@ 25°C
440
1 600
1 600
25