GE AKR-30 Series Maintenance Manual page 184

SECTIO N 1 5-EC Trip Device (Cont . )
1 5.4.1 ADJ USTM ENTS
The only adjustment to be made on the reverse current de­
vice is to make sure that the trip rod has a minimum overtravel
of 1 /32 in. beyond the point of tripping the breaker. This adjust­
ment should have to be made only when an old device is being
replaced by a new one.
The new device will be factory adjusted so that the top end of
the trip rod (3) will extend 1 /2 in. above the top of the device
case, and no additional adjustments of the trip rod should be re­
quired. To obtain the proper 1 /32 in. overtravel, close the
breaker and proceed as follows:
1 . Loosen the locking nut. (28).
2. Manually lift the trip rod and vary the position of the ad­
justing nut (2A), this establishing the position of the adjusting
nut where the breaker is just tripped.
Be sure to keep clear of moving breaker parts when
NOTE:
tripping the breakers.
3. With this position of the adjusting nut established, advance
the adjusting nut upward one and one-half turns.
4. Tighten the locking nut and the minimum 1 /32-in. over­
travel of the trip rod should be obtained .
1 5.4.2 REPLACEMENT
After removing the wiring for the potential coil the reverse cur­
rent device can be removed and replaced by following the pro­
cedure outlined for replacing the series overcurrent device. See
Section 1 5 .6. For wiring, see Fig . 1 25 .
1 5.5 SWITCHETTE FEATU RE
The switchette is operated by the long-time delay function. Its
purpose is to provide a set of contacts that will close before an
overload occurs. This device will not trip the breaker on over­
load it will trip on instantaneous only.
The switchette feature is available only in type EC-1 devices.
The switchette is used in one pole and EC-1 trips in the other
poles. For the alarm to be effective in indicating the overload
before the other poles trip the breaker, the device must have
less time delay than the other two poles; this is accomplished
by using a lower characteristic on the alarm device than the
other poles or setting the alarm devices long time setting at
80%.
90
1 5.6 TRIP DEVICE REPLACEMENT
Overcurrent devices on AKR30
dismounted by removing the fastening hardware at the rear of
the breaker and withdrawing the device. EC devices, after being
unfastened as shown in Figures 1 26 and 1 27, and having the
clamps on the case in the front removed, may be lowered clear
of the breaker. You do not have to separate frames on these
breakers.
FIG. 1 26 DISCONNECTING EC COIL
FIG. 1 27 DISCONNECTING EC FRAME
&
AKR50 breakers may be