Caution:
Before instaffing in a nuclear application, determine
that the product is intended tor such use.
Warning:
Disconnect power before installing or seNicing.
Description
ABB 300-Une full-voltage magnetic motor starters include a magnetic
contactor and a three-leg block overload relay, providing motor
protection against running and stalled motor overloads. The
overload relay may be provided with a yellow trip indicator which is
located to the right of the reset arm, and is visible when the overload
relay is tripped.
OVERLOAD RELAY
HEATER SLOTS
Figure 1. Typical 300-Une magnetic starter.
Ratings
CR305 contactors are suitable for use on a circuit capable of deliver
ing not more than 10,000 RMS symmetrical amperes, 600 volts max
imum when protected by H, J, K1, KS, RKi, and RK5 class fuses or
a circuit breaker having an interrupting rating not less than 10,000
RMS symmetrical amperes, 600 volts maximum.
Installation
Before connecting starter to power supply:
1. Remove a!! packing.
2. Clean magnet mating surfaces of any dirt or foreign matter.
3. Select and install heaters in accordance with heater table which
accompanies each starter unit.
Caution: Do not energize starter before heaters are instalfed.
4. Operate movable magnet by pressing on the nameplate to assure
free movement.
5. Mount starter on a sturdy vertical support.
6. Make the electrical connections.
7. The overload relay can be reset manually by depressing and
releasing the reset arm.
8. The ultimate tripping current of the installed relay heater can be
adjusted ± i0% by using the adjustment dial, shown in Figure 1.
Coil Replacement
1. Remove power from the device.
2. Unscrew one end of the retainer (B-Figure 1) and slide it out of
the slot.
3. Remove movable magnet assembly.
4. Loosen four coil retainer screws (C-Figure 1}. Press against coil
and pull up and out on coil retainers (A-Figure 1).
5. Remove coil from magnet.
6. Replace coll.
7. Reassemble device by reversing procedure.
Contact Replacement
1 . Perform steps 1 through 5 under
Coil Replacement.
2. Remove complete magnet assembly by pulling entire assembly
from the contactor assembly,
3. With the magnet assembly resting on its side, remove the
movable arm by sliding it out the back of the assembly.
4. Depress movable contact and spring and slide movable contact
from movable arm.
5. Remove screws holding stationary contact in place and remove
stationary contact.
6. Reassemble by reversing the above procedure. When reassem
bling, note that the cover will fit only one way. Magnet and
movable arm will fit either way but will be quleter if reassembled
the same way they were taken apart.
NOTE: Do not attempt to remove or replace arc traps in molded
cover.
Figure 2.
Overload Relay Check
Remove power from the device, disconnect the control wiring from
the relay terminals, and place a bell set or resistance measuring in
strument across the relay terminals. Depress and release the reset
arm to insure the relay is reset. In this condition there should be
continuity between the terminals. Depress the white manual check
operator to trip the relay. !n the tripped condition the circuit between
GEH-4839 INSTALLATION INSTRUCTIONS
300-Line CR305/CR306/CR309 Magnetic
Contactors,
Starters, & Reversers
For
NEMA Size 5
Supersedes GEH-4839 and GEH-4869
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