Viking DDBF036LSS, Service Manual

Page: 34 / 50

Service Procedure
34 ©2007 Viking Preferred Service
Charging
NOTE
: Do not use captured or recycled refrigerant in
units. Captured or recycled refrigerant voids any
warranty.
NOTE
: Charge system with exact amount of refrigerant.
Refer to unit serial plate for correct refrigerant
charge. Inaccurately charged system will cause
future problems.
To charge system:
Close valves “A” to vacuum pump and “C” to vacuum
gauge and “E” to low side manifold gauge.
9. Set scale on dial-a-charge cylinder for
corresponding HFC134a pressure reading.
10. Open valve “F” to charging cylinder and let exact
amount of refrigerant flow from cylinder into system.
Close valve.
Low side gauge pressure should rise shortly after
opening charging cylinder valve as system pressure
equalizes through capillary tube.
If pressure does not equalize, a restriction typically
exists at capillary/drier braze joint.
11. If pressure equalizes, open valve “E” to low side
manifold gauge and pinch off high side drier process
tube.
12. Start compressor and draw remaining refrigerant
from charging hoses and manifold into compressor
through compressor process tube.
13. To check high side pinch-off drier process tube.
Close valve “D” to high side gauge. If high side
pressure rises, repeat high side pinch-off and open
valve “D”. Repeat until high side pinch-off does not
leak.
14. Pinch-off compressor process tube and remove
charging hose. Braze stub closed while compressor
is operating.
15. Disconnect power. Remove charging hose and
braze high side drier process tube closed.
16. Recheck for refrigerant leaks.
Refrigerant Charge
Refrigerant charge in all capillary tube systems is critical
and exact amount is required for proper performance.
Factory charges are shown on serial plate.
NOTE:
Do not use refrigerant other than shown on
serial plate.
HFC134a Service Information
HFC134a is alternative refrigerant for CFC12.
HFC134a has an ozone depletion potential (ODP) factor
of 0.0 and a global warming potential (GWP) factor of
0.27. HFC134a is not flammable and has acceptable
toxicity levels. HFC134a is not interchangeable with
CFC12. There are significant differences between
HFC134a and CFC12 which must be considered when
handling and processing refrigeration system.
Health, Safety, and Handling
Health, safety and handling considerations for HFC134A
are virtually no different than those for CFC12.
Health, Safety, and
Handling CFC12 HFC134a
Allowable overall
exposure limit 1,000 ppm Same
Vapor exposure to skin No effect Same
Liquid exposure to skin Can cause frostbite Same
Vapor exposure to eye Very slight eye irritant Same
Liquid exposure to eye Can cause frostbite Same
Above minimum
exposure limit Can cause Asphyxiation,
Tachycardia, and Cardia
Arrhythmias
Same
Safety and handling Wear appropriate skin
and eye protection. Use
with adequate
ventilation.
Same
Spill management Remove or extinguish
ignition or combustion
sources. Evacuate or
ventilate area.
Same
Fire explosion hazards May decompose if
contact with flames and
heating elements.
Container may explode
if heated due to resulting
pressure rise.
Combustion products
are toxic.
Same
Disposal procedures Recycle or reclaim. Same