Friedrich H)A09K34L 用户手册

 

Proper refrigerant charge is essential to proper unit opera-

tion. Operating a unit with an improper refrigerant charge will 

result in reduced performance (capacity) and/or efficiency. 

Accordingly, the use of proper charging methods during ser-

vicing 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  flow  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  specific  type  of 

failure will be influenced 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 sufficient 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. 

Unplug and/or disconnect all electrical power 

to the unit before performing inspections, 

maintenances or service.  

 

Failure to do so could result in electric shock, 

serious injury or death.

Sealed Refrigeration System contains refrigerant 

and oil under high pressure.

Proper safety procedures must be followed, 

and proper protective clothing must be worn 

when working with refrigerants.

Failure to follow these procedures could 

result in serious injury or death. 

ANY SEALED SYSTEM REPAIRS TO COOL-ONLY MODELS REQUIRE THE INSTALLATION OF A LIQUID LINE DRIER. 

ALSO, ANY SEALED SYSTEM REPAIRS TO HEAT PUMP MODELS REQUIRE THE INSTALLATION OF A SUCTION LINE DRIER.

EQUIPMENT REQUIRED:
  1.  Voltmeter
  2.  Ammeter
  3.  Ohmmeter
  4.   E.P.A. Approved Refrigerant Recovery System
  5.  Vacuum  Pump  (capable  of  200  microns  or  less 

vacuum.)

  6.  Acetylene Welder
  7.  Electronic Halogen Leak Detector capable of detect-

ing HFC (Hydrofluorocarbon) refrigerants.

  8.  Accurate refrigerant charge measuring device such 

as:

    a.  Balance Scales - 1/2 oz. accuracy
    b.  Charging Board - 1/2 oz. accuracy

9.      High Pressure Gauge - (0 - 750 lbs.)
10.  Low Pressure Gauge - (30 - 200 lbs.)
 11.  Vacuum Gauge - (0 - 1000 microns)

 12.  Facilities for flowing nitrogen through refrigeration tubing 

during all brazing processes.

EQUIPMENT MUST BE CAPABLE OF:
  1.  Recovering refrigerant to EPA required levels.
  2.   Evacuation from both the high side and low side of the 

system simultaneously.

  3.  Introducing  refrigerant  charge  into  high  side  of  the 

system.

  4.  Accurately  weighing  the  refrigerant  charge  actually 

introduced into the system. 

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