GSZH5 Service Manual
103
SERVICING
Suction Line Drier Clean-Up Method
The POE oils used with R410A refrigerant is an excellent
solvent. In the case of a burnout, the POE oils will remove
any burnout residue left in the system. If not captured by
or other system components, causing a failure of the
replacement compressor and/or spread contaminants
throughout the system, damaging additional components.
for pressure drop after the system has operated for a
time. It may be necessary to use new tubing and form as
required.
immediately out of the compressor stub must be
discarded due to burned residue and contaminates.
1. Remove compressor discharge line strainer.
2. Remove the liquid line drier and expansion valve.
3. Purge all remaining components with dry nitrogen or
carbon dioxide until clean.
4. Install new components including liquid line drier.
5. Braze all joints, leak test, evacuate, and recharge
system.
6. Start up the unit and record the pressure drop across
the drier.
7. Continue to run the system for a minimum of twelve
(12) hours and recheck the pressure drop across the
drier. Pressure drop should not exceed 6 PSIG.
8. Continue to run the system for several days, repeatedly
checking pressure drop across the suction line drier. If
the pressure drop never exceeds the 6 PSIG, the drier
has trapped the contaminants. Remove the suction line
drier from the system.
9. If the pressure drop becomes greater, then it must be
replaced and steps 5 through 9 repeated until it does
not exceed 6 PSIG.
determined and corrected before the new compressor
is started.
Refrigerant Piping
The piping of a refrigeration system is very important in
relation to system capacity, proper oil return to compressor,
pumping rate of compressor and cooling performance of
the evaporator.
POE oils maintain a consistent viscosity over a large
temperature range which aids in the oil return to the
compressor; however, there will be some installations
which require oil return traps. These installations should
be avoided whenever possible, as adding oil traps to the
refrigerant lines also increases the opportunity for debris
and moisture to be introduced into the system. Avoid long
running traps in horizontal suction line.
Duct Static Pressures
This minimum and maximum allowable duct static pressure
section.
Tables are also provided for each coil, listing quantity of air
(CFM) versus static pressure drop across the coil.
Too great an external static pressure will result in
air can cause poor humidity control and condensate to be
Too much air can also cause motor overloading and in
many cases this constitutes a poorly designed system.
Single Piece Air Handler External Static
1. Using a Inclined Manometer or Magnehelic gauge,
measure the static pressure of the return duct at the
inlet of the air handler, this will be a negative pressure
(For Example: .30” wc).
2. Measure the static pressure of the supply duct at
the outlet of the air handler, this should be a positive
pressure (For Example: .20” wc).
3. Add the two readings together (For Example: .30” wc +
.20” wc = .50” wc total external static pressure).
read directly on the manometer if so desired.
4.
air (CFM) at the measured external static pressure.