Viking Designer DDFB304, Service Notebook

10

WARNING

To avoid electrical shock which can cause severe personal injury or death, disconnect 
power to refrigerator using power switch before servicing.  Wires removed during 
disassembly must be replaced on proper terminals to insure correct earth ground and       

  polarization.  After servicing, reconnect power using power switch. 

 
Evacuation and Charging 
 

CAUTION:  To avoid risk of fire, sealed 
refrigeration system must be air free.  To 
reduce risk of air contamination, follow 

evacuation procedures exactly.

 
NOTE: 

Before  opening  any  refrigeration         

system, EPA regulations require refrigerant in 
system to be captured for safe disposal. 
Proper evacuation of sealed refrigeration system 
is an important service procedure.  Usable life 
and operational efficiency greatly depends upon 
low completely air, moisture and other non-
condensables are evacuated from sealed system. 
 
Air in sealed system causes high condensing 
temperature and pressure, resulting in increased 
power requirements and reduced performance. 
 
Moisture in sealed system chemically reacts 
with refrigerant and oil to form corrosive 
hydrofluoric and hydrochloric acids.  These 
acids attack motor windings and parts, causing 
premature breakdown. 
 
Before opening system, evaporator coil must be 
at ambient temperature to minimize moisture  
infiltration into system. 
 

Evacuation:  

To evacuate sealed refrigeration 

system: 

1.

Connect vacuum pump, vacuum tight 
manifold set with high vacuum hoses, 
thermocouple vacuum gauge and 
charging cylinder as shown in 
illustration.  Evacuation should be done  
through I.D. opening of tubes not 
through line piercing valve. 

2.

Connect low side line to compressor 
process tube. 

3.

Connect high side line to drier/process 
tube. 

4.

Evacuate both simultaneously.  With 
valve “C” and “F” closed, open all other 
valves and start vacuum pump. 

    Equipment Setup For Evacuation and Charging 

5.

After compound gauge (low side) drops 
to approximately 29 inches gauge, open 
valve “C” to vacuum thermocouple 
gauge and take micron reading. 

NOTE: 

A high vacuum pump can only produce 

a good vacuum if oil in pump is not 
contaminated. 

6.

Continue evacuating system until 
vacuum gauge registers 200 microns. 

7.

At 200 microns, close valve “A” to 
vacuum pump and allow micron reading 
in system to balance.  Micron lever will 
rise. 

•

If in 2 minutes, micron level stabilizes at 
400 microns or below, system is ready 
to be charges. 

•

If micron level rises above 400 microns 
and stabilizes, open valve “A” and 
continue evacuating. 

•

If micron reading rises rapidly and does 
not stabilize, a leak still exists in system. 
Close valve “A” to vacuum pump an 
valve “C” to vacuum gauge. Invert 
charging cylinder and open charging 
cylinder valve “F” to add partial charge 
for leak checking.  With leak detector, 
check manifold connections and system 
for leaks.  after locating leak, capture 
refrigerant, repair leak, and begin at step 1.