2
5. Remove coil from magnet.
6. Replace coil.
7. Reassemble device by reversing
procedure.
Contact removal
Movable contacts can be inspected
and replaced in seconds —without
tools (Figure 3).
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 reassembling, note
that the cover will fit only one way.
Magnet and movable arm will fit either
way but will be quieter if reassembled
the same way they were taken apart.
NOTE: Do not attempt to remove or
replace arc traps in arc chute cover.
When reassembling, note that the arc
chute cover will only fit one way and is
marked “TOP” in upper right-hand corner.
Check for welded contacts
in overload relay
This feature permits maintenance
personnel to check for welded relay
contacts by simply depressing the white
operator located at the top of the overload
relay contact housing. When the relay is in
the reset condition, an audible “click” will
be heard when the operator is depressed,
indicating that the contacts are operating
normally. A continuity check can also be
made by disconnecting the control wiring
from the terminals of the relay and placing
a bell set or a resistance measuring
instrument in the circuit. Connecting
either of these across the relay terminals
will indicate the relay contact is closed
until the contact-check operator is
depressed, opening the circuit. The
exclusive manual contact operation check
gives positive assurance that contacts
have not welded due to short circuits in
the control wiring.
Simple maintenance
300/400-line starters and contactors
require virtually no corrective
maintenance. Preventive maintenance
will assure many years of dependable
on-line service.
1. Always remove power from device
before performing any maintenance.
2. Keep magnet mating surfaces free
of accumulated dirt or dust.
3. DO NOT OIL OR GREASE the magnet
mating surfaces.
4. Contacts are carefully designed for
maximum life. They need only be
replaced when nearly all the silver tip
is gone and the contact tip support is
exposed. DO NOT FILE the contacts.
Filing or otherwise dressing the
contacts only results in lost tip material
and reduces contactor or starter life.
5. The ultimate tripping current of the
installed relay heater can be adjusted
±10% by using adjustment dial.
—
Replacement coils
For two- and three-pole devices, order cat. no. 55-536548G plus number in table below.
Example: 55-536548G002 is rated 115–120 V, 60 Hz/110 V, 50 Hz.
Frequency
115–120 V
200–208 V
230–240 V
–
460–480 V
575–600 V
60 Hz
002
023
003
–
004
005
Frequency
110 V
–
220 V
380 V
440 V
550 V
50 Hz
002
–
003
064
004
005
—
Accessory kits
First NO auxiliary contact for CR305, CR306 (right-side mounting)
CR305X500A
First NC auxiliary contact for CR305, CR306 (right-side mounting)
CR305X500B
First NO-NC auxiliary contact for CR305, CR306 (right-side mounting)
CR305X500C
Additional NO auxiliary contact for all forms
CR305X100D
Additional NC auxiliary contact for all forms
CR305X100E
Surge suppressor
CR305X146C
Lug kit ( 1 lug and hardware)
55-186556G003
—
Figure 3 — reference diagram (representation only)
Stationary
contact
screws
Stationary
contacts
Movable
contacts
Movable arm
return spring
(not shown)
Spring seat
Spring
