Carrier 19FA Betriebsanleitung PDF herunterladen (Seite 24)

HVAC Training

Page : 24 of 42

Title:

Chiller Maintenance

Lesson Plan

NMH30C000105

CRDR 2850439

Thread sealer on Chiller 1MECBE01 Guide Vane Shaft Failure Description

HVAC Maintenance found one of the set screws loose on the guide vane shaft crank arm during

the

performance of normal chiller maintenance on essential chiller 1MECBE01 during U1R11. The

crank arm

was loose, but was not slipping on the shaft. One of three (3) set screws was found loose. The

technicians recalled a recent INPO Operating Experience report (OE) that identified a similar

problem at

the Hope Creek station.

OE 21321 identified an incident at the Hope Creek station where the control linkage set screw can

loosen

and allowed the crank arm to slip on the guide vane shaft. Hope Creek applied Loctite thread

sealer 242

(medium strength thread sealer) to the set screw threads to help hold the set screws in place and

help to

prevent the set screws from backing out.

HVAC Maintenance and Maintenance Engineering viewed the use of the medium strength thread

sealer

as a good maintenance practice. HVAC Maintenance generated CMWO 2845865 to apply Loctite

thread

sealer to the crank arm set screws on chiller 1MECBE01. CMWO 2846522 was generated to apply

Loctite thread sealer to the crank arm set screws on chiller 1MEC AE01.

Essential chiller 1MECBE01 was returned to service following maintenance. About 36 hours after

start up

the chiller tripped on low refrigerant temperature. Troubleshooting performed under CMWO

2850424

found that the guide vane actuator was not responding to the chiller demand. The guide vane

linkage was

disconnected from the actuator and found to be extremely difficult to move by hand. The guide

vane

linkage should be able to operate smoothly over the full range of the guide vane. The decision was

made

to pump down the chiller and go in and look at the guide vane for a possible problem with the

internal

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Carrier 19FA Betriebsanleitung Seite 24