Service Manual | VMH Series | Heat Controller, Inc. |
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2. Deep Vacuum Method
The deep vacuum method requires a vacuum pump capable of pulling a vacuum of 500 microns and a vacuum of 500 microns and vacuum gage capable of accurately measuring the vacuum depth. The deep vacuum method is the most positive way of assuring a system is free of air and liquid water.
1.Vacuum pressure should pull down below 500 microns in 2 minutes.
2.Evacuate system for 30 minutes.
3.Shut valve to vacuum pump off.
4.After 10 minutes read pressure.
If pressure remains below 1000 microns, system is ready.
If pressure is between 1000 and 2000 microns continue evacuation for additional 30 minutes. If pressure is above 2000 microns, there is a leak in the system.
3.Triple Evacuation Method
The triple evacuation method should only be used when vacuum pump is only capable of pumping down to a 28” Hg. vacuum and system does not contain any liquid water.
1.Pump system down to 28”Hg. and allow pump to continue operating for an additional 15 minutes.
2.Close high and low side valves on gauge manifold and shut off vacuum pump.
3.Connect a nitrogen cylinder and regulator to system and open until system pressure is 2 psig.
4.Close service valve and allow system to stand for 1 hour. This will allow dry nitrogen to diffuse throughout the system absorbing moisture.
5.Complete this procedure until system until it is able to hold a deep vacuum then release charge into system.
4.Final Tubing Check
IMPORTANT: Check to be certain factory tubing on both indoor and outdoor unit has not shifted during shipment. Ensure tubes are not rubbing against each other or any sheet metal. Pay close attention to feeder tubes, making sure wire ties on feeder tubes are secure and tight.
7. Operation characteristics
CAUTION:
1.Operation of air conditioner beyond the above conditions may cause certain protections to occur.
2.Room relative humidity should be less than 80%. If the air conditioner operates in excess of this value, the surface of the air conditioner may cause condensation. If condensation does occur, place the vertical air louver to it’s maximum angle (vertically to the floor) and set the fan to high speed.
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