Recommended Maintenance
CVHH-SVX001A-EN 95
1. With the purge unit operating, check the purge tank
condensing activity by observing the liquid refrigerant
flow in the moisture-indicating sight glass located in
the liquid drain line immediately after the filter drier
canister. A lack of visible refrigerant flow in the sight
glass indicates one of the following:
• A pump-out cycle is necessary
• A problem exists with the purge heat transfer circuit
(such as the condensing unit, expansion device, or
purge evaporator coil)
• A problem exists in the purge control subsystem
• Refrigerant vapor from the chiller condenser is
blocked or restricted
2. Check the moisture-indicator sight glass. Replace the
filter-drier core if moisture is indicated.
Note: The need for frequent changes of the filter drier
could be an indication of significant chiller air or
tube leaks.
Semi-Annual Maintenance
Perform the following maintenance procedure on a semi-
annual basis:
1. Inspect the air-cooled condenser coil and clean as
needed. Clean the coil from the fan side using
compressed air or coil cleaner. A dirty coil will reduce
purge efficiency and capacity.
2. Inspect the purge tank and carbon tank insulation for
any damage or degradation. Make any needed repairs
to the insulation.
Annual Maintenance
Perform the following maintenance procedure on an
annual basis:
1. Perform the semi-annual maintenance procedures.
2. Open the purge control panel and check all internal
components for such problems as corrosion, terminal
tightness, or signs of overheating.
3. Change the filter-drier assembly.
Inspecting the Moisture Indicator
Monitor the quality of the liquid refrigerant in the chiller by
periodically inspecting the moisture indicator. The
indicator will show “ wet” whenever the chiller moisture
exceeds the levels shown in
Tab l e 22. Notice that the
indicator becomes more sensitive as the temperature
decreases. (The moisture indicator normally operates at
equipment room ambient temperatures.)
A “ wet” indication for more than 72 hours typically
indicates that the filter-drier is saturated and should be
replaced. In some cases in which a substantial amount of
moisture has accumulated, such as when the chiller has
been serviced, several filter-drier assembly changes may
be required before a satisfactory moisture level is
achieved. A reoccurring or persistent “ wet” indication is a
sign of possible chiller air or water infiltration.
Inspect the moisture indicator only under the following
conditions:
• The chiller is operating.
• The purge unit is operating and has been allowed
sufficient time to properly remove system moisture
(allow a minimum of 72 hours after replacing filter-
drier).
Maintaining the Moisture-Indicating Sight
Glass
In normal operating conditions, the moisture-indicating
sight glass should not require maintenance beyond
keeping the sight glass clean. However, the sight glass
should be replaced after any major repair to the unit has
taken place, or if it is on a unit in which severe moisture
contamination is known to have occurred.
Be aware that it is normal for the sight glass to indicate the
presence of moisture for a period of least 72 hours after it
is installed and after it has been exposed to atmosphere.
Allow a minimum of 72 hours after sight glass installation
or filter-drier service before using the sight glass to
determine the system moisture content.
Removing Air After Servicing the Chiller
Air that leaks into a chiller during servicing needs to be
removed so that the chiller can operate normally. The
purge pump-out system, which performs this function,
may operate for a long time to remove the air before
cycling off for the first time. This is due to the large amount
of non-condensables and the relatively small amount of
refrigerant being drawn into the purge tank.
Important: Do not bypass or remove the pump-out
restrictor of the EarthWise Purge system.
Doing so could reduce the efficiency of the
purge system. The purge system has a
faster air exhaust rate than previous purge
systems, which makes bypassing or
removing the restrictor unnecessary.
The Daily Pumpout Limit determines how long the purge
pump-out compressor can operate continuously without
generating a Purge Daily Pumpout Exceeded diagnostic,
which will shut off the purge system. You can disable the
Table 22. Refrigerant moisture content as determined by
moisture indicator
Refrigerant
moisture level
R-1233
zd
( E)
23 .9°C
( 75°F)
37 .8°C
( 100°F)
51 .7°C
( 125 °F)
Dry Below 20 Below 30 Below 35
Caution 20–50 30–80 35–100
Wet Above 50 Above 80 Above 100
Note: Refrigerant moisture content given in parts per million (ppm).
To Next Page
Loading...
