Richards 137NP, Инструкция по эксплуатации, Страница: 17 / 53

9
7. Yearly
Fully inspect and test protectors including relays and perform the following preventive
maintenance.
a. Remove breaker from the enclosure and inspect and clean the contacts.
b. Check wiring terminals for tightness.
c. Remove trip mechanism and inspect and clean mechanism if necessary. The
protector mechanism is thoroughly lubricated at the factory and this lubrication
should last for some time. However, if it appears that the mechanism requires
lubrication, use SAE-30 machine oil on bearings. Wipe off all excess as the
excess will collect dirt and nullify the effect of the lubricant.
d. The bearings of the secondary latch shaft, Figure 15, should have just a drop of
SAE-30 machine oil added if necessary and the latch surface should be coated
very thinly with high grade petroleum jelly, to prevent rust.
e. Check the level of the lubricant in the gearbox, Figure 17. If necessary add
sufficient #4 hydraulic oil
f. Remove one brush holder and brush from motor and inspect commutator surface
with flashlight. If necessary, remove and disassemble motor and clean
commutator.
g. Lubrication of the motor bearings should not be necessary during the life of the
motor. However, if lubrication is found necessary after a number of years,
remove the motor, dismantle it, wash the bearings out thoroughly and repack them
with a small quantity of grease.
h. Clean torque brake when motor is removed.
i. Check auxiliary switch contacts and clean if necessary.
j. Check motor control device contacts and clean if necessary.
k. Check mechanical indicator.
8. After Heavy Primary Short Circuits
Inspect protectors which have interrupted short circuits, cleaning the devices and
resurfacing the breaker contacts.
9. De-energize Primary Feeders
Each feeder should clear completely, as indicated by the feeder voltmeter, if all the
protectors are set to trip on transformer exciting current. On re-energizing the feeder,
each protector should reclose as the load increases.