Figure 6.
Tandem and Trio
Oil equalizer rotolock
connection fitting
Oil equalizer lines
TANDEM
TRIO
General Information
COM-SVN01D-EN
11
Repair Recommendations
WARNING
Explosion Hazard and Deadly Gases!
Failure to follow all proper safe refrigerant handling
practices could result in death or serious injury.
Never solder, braze or weld on refrigerant lines or any
unit components that are above atmospheric pressure
or where refrigerant may be present. Always remove
refrigerant by following the guidelines established by
the EPA Federal Clean Air Act or other state or local
codes as appropriate. After refrigerant removal, use dry
nitrogen to bring system back to atmospheric pressure
before opening system for repairs. Mixtures of
refrigerants and air under pressure may become
combustible in the presence of an ignition source
leading to an explosion. Excessive heat from soldering,
brazing or welding with refrigerant vapors present can
form highly toxic gases and extremely corrosive acids.
Mechanical Failure
Replace only the failed compressor in a tandem or trio set.
Important:
On tandem or trio assemblies, the suction
and discharge lines must NOT be modified,
except for the use of slip joint couplings.
Other modification may cause oil return
issues and lead to compressor failure. Cut
the lines in a convenient place, remove the
compressor, and then unbraze the lines
from the compressor. On reinstallation,
reinstall lines to compressor and
reassemble the cut lines utilizing a slip
coupling. See
for suggested
area to cut the discharge and suction line.
Figure 7.
Suggested areas to cut refrigerant lines
Suggested area to cut the
refrigerant lines so that
they can be reinstalled
Minimize system and compressor open times to avoid
excessive moisture absorption by the POE oil. Maximum
suggested open time is 15 minutes.
Drain and replace oil in all the non-failed compressors.
Note:
For CSHD compressors, this requires removing oil
using a suction device through the oil equalizer
rotolock fitting (see
). Use a
dedicated device for removing oil. It is good
practice to flush the suction device with clean oil
prior to use.
The CSHN compressor has an oil drain with a Schrader
®
valve that can be used to remove the oil (see
).
Replace unit liquid line filter-drier. This is a very important
part of controlling moisture in R-410A POE oil systems.
