78
Instruction Booklet
IB 33-790-1J
Effective November 2010
Instructions for Low Voltage Power
Circuit Breakers Types DS and DSL
EaToN CorPoraTIoN www.eaton.com
Fig. 88 Open Position Stop and Anti-rebound Latch.
To replace the stationary contacts, the disconnect fingers
on the rear are removed and then the two bolts holding
the upper contact assembly to the molded base. With-
draw the contact assembly from the front. This should be
replaced with a new contact assembly. Make sure that all
bolts are securely tightened. Close the circuit breaker
and check all contact dimensions as described in Section
12.1.2.
12.1.2.2 DS-632 and DS-840
In addition to the requirements for the DS-206, DS-206S,
DS-416, DS-416S and DS-420 above:
The lower main fixed contacts should be inspected to
ensure that they have adequate contact pressure. This is
determined by pin “X” being free to slide in the contact
cage (See Figures 86 and 87). Unlike DS-206/DS-416/
DS-420 breakers, the top row of fixed main contacts are
compressed beyond parallel position to assure adequate
contact pressure for lower row of fixed main contacts.
12.1.3 Replacement of Contacts
12.1.3.1 DS-206
Both moving main and arcing contacts are held between
the two moving arms by two bolts with self-locking nuts.
Removal of the two bolts permits the replacement of the
moving contacts. These bolts must be securely tightened
after replacement.
The fixed arcing contacts are held by a single bolt pass-
ing through the contacts and their pressure springs. On
reassembly the self-locking nut is tightened so that a
dimension of 3.12 inches is obtained between the inside
surfaces of the flat washers on the spring ends.
12.1.3.2 DS-416, DS-416S, DS-420, DS-632 and
DS-840
The moving arcing and main contacts are secured to the
moving contact assembly by two bolts. Removal of these
bolts permits the replacement of the moving contacts.
To change the fixed arcing and main contacts, the fixed
contact assembly must first be removed from the pole
unit. Remove the disconnect fingers, remove the screws
holding the contact assembly to the pole unit base and
withdraw the contact assembly.
Obtain a new or reconditioned assembly and reassemble
in the pole unit, with the holding screws finger tight. Close
circuit breaker and check the dimensions A (Figures 85,
86, and 87); they should be approximately equal. If not,
trip breaker and adjust fixed contact system until align-
ment is obtained. Tighten screws and contacts as
described in 12.2.3.
12.1.4 Arc Chutes
The V-shaped slots in the arc chutes will undergo slow
erosion with arc interruptions. Switching operations will
give them a pitted, mottled and sooty appearance. This is
normal. Heavy fault interruptions will cause greater arc
erosion.
If the steel splitter plates have more than 1/4 inch of
material eroded away at the top of the V-shaped slots,
arc chutes should be replaced. This can be determined
by comparing a plate near the center with a plate near
the end.
12.1.5 General Inspection
Look over all visible parts possible for missing pin retain-
ers, loose nuts, bolts or screws, bent, worn or damaged
parts. Make appropriate corrections to anything found out
of order.
After any inspection make sure all parts are properly
installed on the breaker, especially arc chutes and all four
barriers.
12.1.5.1 Power Operated Mechanisms
Examine the driving face of the oscillator pawl. Refer to
Figures 15 and 16. Normal operation of the spring charg-
ing mechanism will result in the removal of plating from
the face of the pawl.
However, if the face is chipped, distorted or broken, it
should be replaced. Use Kit 694C525G01.
