York YMC2 A, Operation And Maintenance

JOHNSON CONTROLS

23

Section 3 - Maintenance

Form 160.78-O1 

Issue date: 05/19/2021

3

of leakage, the corks may blow from the end of a 

tube, indicating the location of the leakage. If not, 

if will be necessary to make a very thorough test 

with the leak detector.

4.  After the tubes have been corked for 12 to 24 

hours, have two people carefully test each tube at 

both ends of the evaporator. One person can re-

move corks at one end of the evaporator and the 

second person can remove corks at the opposite 

end and handle the leak detector. Start with the top 

row of tubes in the section being investigated. Re-

move the corks at the ends of one tube simultane-

ously and insert the exploring tube for 5 seconds. 

This should be long enough to draw into the de-

tector any refrigerant gas that might have leaked 

through the tube walls. Place a fan at the end of 

the evaporator opposite the detector. This ensures 

that any leakage wi travel through the tube to the 

detector.

5. 

Mark any leaking tubes for later identification.

6.  If any of the tube sheet joints are leaking, the leak 

should be indicated by the detector. If a tube sheet 

leak is suspected, its exact location may be found 

by using a soap solution. A continuous buildup of 

bubbles around a tube indicates a tube sheet leak.

Compressor

Maintenance for the compressor assembly consists of 

observing the operation of the compressor.
If the control panel warns of excessive landings of the 

magnetic bearing motor, notify the nearest Johnson 

Controls office to request the presence of a Johnson 

controls Service Technician. The technician can assess 

the condition of the touchdown bearings using elec-

tronic tools.

Electrical controls

For information covering the OptiView™ Control 

Center operation, refer to the 

YMC

2

 OptiView

TM

 Con-

trol Center Operations Manual (Form 160.78-O2)

.