Hitachi N342555809, Установка, эксплуатация и обслуживание

Страница: 17 / 46

PV-250 Track Relay
Copyright 2019 SM 4574F, Rev. 4, March 2019 3-1
3. MAINTENANCE
This section provides the necessary periodic preventive maintenance procedures that
must be performed to ensure continuous, proper, and efficient operation of the PV-250
style relays covered in this manual. This maintenance section covers periodic
inspections and performance tests.
3.1. Periodic Performance Test
3.1.1. Cleaning
Before inspecting and testing the relay, use a soft cloth to clean the exterior to remove
any dirt or dust that may have collected. A safe cleaning solution of alcohol and water
or common laundry detergent may be used for removal of accumulated dirt, grease,
etc.
3.1.2. Service Requirements
3.1.2.1. General
Track relays must be inspected and tested at least every two (2) years. The tests and
inspections are to include: pick-up current, drop-away current, timing of slow operating
and timing relays; and visual inspection of contacts for damage or misalignment,
corrosion or other contamination of parts, loose parts inside of the cover, broken seal,
and cracked or broken cover.
Relays not passing the above stated tests and inspections must be replaced and not
returned to service until the operating characteristics and conditions are in accordance
with STS USA specifications.
3.1.2.2. Testing
Calibration Table 3-1 should be used for factory/shop environment only.
Calibration Table 3-3 should be used for field testing relays. This includes initial in-
service testing prior to going into service.
Relays that do not meet test and/or calibration specifications must be removed from
service for shop repair.
3.2. Calibration
3.2.1. Recommended Test Equipment
Two Variable Autotransformers (Variac) - 115 VAC @ 1.0 amp.
AC Ammeter (True RMS)