Replacement Of Compressors - Toshiba MMY-MUP0721HT9P-UL Service Manual

11-2. Replacement of Compressors

<Checking color of oil in troubled compressor>
• Lay the troubled compressor down, draw a small amount of oil via the
oil equalization pipe, and check its color against color samples.
• Determine the number of compressors to be replaced according to the
color checking result.
ASTM grade: Below 4
ASTM grade: 4 or above
the normal compressor(s).
WARNING
When detaching a pipe by heating with a burner at brazed joint, take care as any oil left in the piping may burn
in a momentary flash of fire when the brazing filler metal melts.
Model: MMY-MUP0721*,0961*,072H1*
For Standard 6,8 ton, High heat 6 ton
[When replacing troubled compressor only]
<Measuring amount of oil in troubled compressor>
Put the troubled compressor above the scale to measure the amount of oil.
Amount of oil in troubled compressor: A [gal] = (Weight of compressor as it was dismantled (lbs) - 57.3Ibs) x 0.1249
(Specific volume of oil: 0.1249 [gal/Ibs])
* The weight of the compressor without oil inside is 57.3Ibs
<Adjusting amount of oil in new compressor> (0.502 gal at shipment)
• Perform the adjustment on the basis of how much oil the troubled compressor contained, A [gal], by
following the steps below.
1
Amount of oil in troubled compressor A [gal]: 0
(1) Adjust the amount of oil in the new compressor to 0.264 gal
(Lay the new compressor down and draw 0.211 [gal] of oil via the oil-equalization pipe.)
Notes:
• Do not draw more than 0.211 [gal] of oil as it may cause damage to the compressor.
• If the troubled compressor contained 0.132gal or less, there may have been a problem with the oil
equalization circuit, etc. Perform checks in accordance with "11-3. Check Procedure to Search Cause of
Compressor Oil Shortage".
2
Amount of oil in troubled compressor A [gal]: 0.264
(1) Adjust the amount of oil in the new compressor to A gal.
(Lay the new compressor down and draw (0.502 - A) [gal] of oil
via the oil equalization pipe.)
3
Amount of oil in troubled compressor A [gal]: 0.502
(1) Adjust the amount of oil in the new compressor to A gal.
(Insert a hose into the discharge pipe or oil equalization pipe of the
new compressor and inject (A-0.502) [gal] of oil using a funnel, etc.)
Replace the troubled compressor only.
Replace both the troubled compressor and
A < 0.264
A < 0.502
A
- 261 -
Compressor
Oil equalization
pipe
Compressor