Semi-Annual M Aintenance; Annual M Aintenance; Inspecting The M Oisture Indicator; M Aintaining The M Oisture-Indicating Sight Glass - Trane CVHH Installation, Operation And Maintenance Manual

1. With the purge unit operating, check the purge tank
condensing activity by observing the liquid refrigerant
flow in the m oisture-indicating sight glass located in
the liquid drain line im m ediately after the filter drier
canister. A lack of visible refrigerant flow in the sight
glass indicates one of the follow ing:
• A pum p-out cycle is necessary
• A problem exists w ith 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 m oisture-indicator sight glass. Replace the
filter-drier core if m oisture is indicated.
N ot e: The need for frequent changes of the filter drier
could be an indication of significant chiller air or
tube leaks.

Semi-Annual M aintenance

Perform the follow ing m aintenance procedure on a sem i-
annual basis:
1. Inspect the air-cooled condenser coil and clean as
needed. Clean the coil from the fan side using
com pressed air or coil cleaner. A dirty coil w ill reduce
purge efficiency and capacity.
2. Inspect the purge tank and carbon tank insulation for
any dam age or degradation. M ake any needed repairs
to the insulation.

Annual M aintenance

Perform the follow ing m aintenance procedure on an
annual basis:
1. Perform the sem i-annual m aintenance procedures.
2. Open the purge control panel and check all internal
com ponents for such problem s as corrosion, term inal
tightness, or signs of overheating.
3. Change the filter-drier assem bly.

Inspecting the M oisture Indicator

M onitor the quality of the liquid refrigerant in the chiller by
periodically inspecting the m oisture indicator. The
indicator w ill show " w et" w henever the chiller m oisture
exceeds the levels show n in
indicator becom es m ore sensitive as the tem perature
decreases. (The m oisture indicator norm ally operates at
equipm ent room am bient tem peratures.)
A " w et" indication for m ore than 72 hours typically
indicates that the filter-drier is saturated and should be
replaced. In som e cases in w hich a substantial am ount of
m oisture has accum ulated, such as w hen the chiller has
been serviced, several filter-drier assem bly changes m ay
be required before a satisfactory m oisture level is
CVHH-SVX001A-EN
Table 22. Notice that the
Recommended M aintenance
achieved. A reoccurring or persistent " w et" indication is a
sign of possible chiller air or water infiltration.
Inspect the m oisture indicator only under the follow ing
conditions:
• The chiller is operating.
• The purge unit is operating and has been allow ed
sufficient tim e to properly rem ove system m oisture
(allow a m inim um of 72 hours after replacing filter-
drier).
Table 22. Refrigerant moisture content as determined by
moisture indicator
Re fr ige r a n t 2 3 .9 °C
m oist ur e le ve l ( 7 5 °F)
Dry Below 20
Caut ion 20–50
Wet Above 50
Note: Refrigerant m oist ure cont ent given in part s per m illion ( ppm ) .
M aintaining the M oisture-Indicating Sight
Glass
In norm al operating conditions, the m oisture-indicating
sight glass should not require m aintenance beyond
keeping the sight glass clean. How ever, the sight glass
should be replaced after any m ajor repair to the unit has
taken place, or if it is on a unit in w hich severe m oisture
contam ination is known to have occurred.
Be aware that it is norm al for the sight glass to indicate the
presence of m oisture for a period of least 72 hours after it
is installed and after it has been exposed to atm osphere.
Allow a m inim um of 72 hours after sight glass installation
or filter-drier service before using the sight glass to
determ ine the system m oisture content.

Removing Air After Servicing the Chiller

Air that leaks into a chiller during servicing needs to be
rem oved so that the chiller can operate norm ally. The
purge pum p-out system , w hich perform s this function,
m ay operate for a long tim e to rem ove the air before
cycling off for the first tim e. This is due to the large am ount
of non-condensables and the relatively sm all am ount of
refrigerant being draw n into the purge tank.
Im port ant : Do not bypass or rem ove the pum p-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
system s, w hich m akes bypassing or
rem oving the restrictor unnecessary.
The Daily Pum pout Lim it determ ines how long the purge
pum p-out com pressor can operate continuously w ithout
generating a Purge Daily Pum pout Exceeded diagnostic,
w hich w ill shut off the purge system . You can disable the
R- 1 2 3 3 ( E)
z d
3 7 .8 °C 5 1 .7 °C
( 1 0 0 °F) ( 1 2 5 °F)
Below 30 Below 35
30–80 35–100
Above 80 Above 100
95