Honeywell R4795A Manual page 14

R4795A
SERVICE
IMPORTANT:
1. Do not clean contacts unless absolutely necessary.
2. Use only Honeywell Contact Cleaner part no. 132569.
Do not use any other type of contact cleaner.
3. Use extreme care to avoid bending the contacts or
changing the specifications or configuration in any
way.
4. Do not use an abrasive or a burnishing tool to clean
contacts.
5. Do not use hard paper such as a business card to clean
contacts.
If relay contacts must be cleaned, use only Honeywell
Pressurized Contact Cleaner, part no. 132569. Honeywell's
chemical analysis laboratory has found this cleaner to be
acceptable for this task. Directions for using this cleaner are
printed on the can.
Do not risk using any other types of contact cleaners.
Honeywell's chemical analysis laboratory tested other pres-
surized type contact cleaners but did not approve them for
these reasons:
1. Some had solvents that could deteriorate plastic parts
and wire insulation.
60-2285—7
2. Some leave an oily residue that will collect dust and
dirt. The residue will also break down to form various
carbonaceous products. Either result will cause early contact
failure.
Do not use an abrasive (sand paper stock, file, etc.) or a
burnishing tool to clean contacts. Its use can cause early
contact failure for these reasons:
1. Some relay contacts are plated with gold for increased
reliability. Burnishing can quickly remove the plating.
2. The radii or points of the contacts are designed with
specific shapes to best serve the intended functions of the
contacts. Burnishing can rapidly alter these contact configu-
rations.
3. Use of an abrasive loosens fine particles of the contact
material that adhere to the surface of the contract, thus in-
creasing its resistance.
4. Contact specifications (contact pressures, press-back,
and gaps) are carefully controlled during manufacturing to
assure maximum contact life. Burnishing can easily change
these specifications.
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