Filter
Top Products
10
NOTE: In order to access the sealed system it will be necessary to install Schrader type fi ttings to the process tubes
on the discharge and suction of the compressor. Proper refrigerant recovery procedures need to be adhered to as
outlined in EPA Regulations. THIS SHOULD ONLY BE ATTEMPTED BY QUALIFIED SERVICE PERSONNEL.
Refrigerant Charging
NOTE: BECAUSE THE RAC SYSTEM IS A SEALED SYSTEM,
SERVICE PROCESS TUBES WILL HAVE TO BE INSTALLED.
FIRST INSTALL A LINE TAP AND REMOVE REFRIGERANT
FROM SYSTEM. MAKE NECESSARY SEALED SYSTEM
REPAIRS AND VACUUM SYSTEM. CRIMP PROCESS TUBE
LINE AND SOLDER END SHUT. DO NOT LEAVE A SERVICE
VALVE IN THE SEALED SYSTEM.
Proper refrigerant charge is essential to proper unit operation.
Operating a unit with an improper refrigerant charge will result in
reduced performance (capacity) and/or effi ciency. Accordingly,
the use of proper charging methods during servicing will insure
that the unit is functioning as designed and that its compressor
will not be damaged.
Too much refrigerant (overcharge) in the system is just as bad (if
not worse) than not enough refrigerant (undercharge). They both
can be the source of certain compressor failures if they remain
uncorrected for any period of time. Quite often, other problems
(such as low air fl ow across evaporator, etc.) are misdiagnosed as
refrigerant charge problems. The refrigerant circuit diagnosis chart
will assist you in properly diagnosing these systems.
An overcharged unit will at times return liquid refrigerant (slugging)
back to the suction side of the compressor eventually causing a
mechanical failure within the compressor. This mechanical failure
can manifest itself as valve failure, bearing failure, and/or other
mechanical failure. The specifi c type of failure will be infl uenced
by the amount of liquid being returned, and the length of time the
slugging continues.
Not enough refrigerant (Undercharge) on the other hand, will cause
the temperature of the suction gas to increase to the point where it
does not provide suffi cient cooling for the compressor motor. When
this occurs, the motor winding temperature will increase causing
the motor to overheat and possibly cycle open the compressor
overload protector. Continued overheating of the motor windings
and/or cycling of the overload will eventually lead to compressor
motor or overload failure.
METHOD OF CHARGING
The acceptable method for charging the RAC system is the
Weighed in Charge Method. The weighed in charge method is
applicable to all units. It is the preferred method to use, as it is the
most accurate.
The weighed in method should always be used whenever a charge
is removed from a unit such as for a leak repair, compressor
replacement, or when there is no refrigerant charge left in the unit.
To charge by this method, requires the following steps:
1. Install a piercing valve to remove refrigerant from the
sealed system. (Piercing valve must be removed from
the system before recharging.)
2. Recover Refrigerant in accordance with EPA
regulations.
3. Install a process tube to sealed system.
4. Make necessary repairs to system.
5. Evacuate system to 250 - 300 microns or less.
6. Weigh in refrigerant with the property quantity of R-22
refrigerant.
7. Start unit, and verify performance.
8. Crimp the process tube and solder the end shut.