![background image](http://html1.mh-extra.com/html/carrier/38gjq-series/38gjq-series_installation-instructions-manual_2560624044.webp)
44
Deep Vacuum Method
The deep vacuum method requires a vacuum pump capable of
pulling a vacuum of 500 microns and a vacuum gage capable of
accurately measuring this vacuum depth. The deep vacuum method
is the most positive way of assuring a system is free of air and
liquid water (see Fig. 89).
500
MINUTES
0
1
2
3
4
5
6
7
1000
1500
LEAK IN
SYSTEM
VACUUM TIGHT
TOO WET
TIGHT
DRY SYSTEM
2000
MICRONS
2500
3000
3500
4000
4500
5000
A95424
Fig. 89 – Deep Vacuum Graph
Triple Evacuation Method
The triple evacuation method should only be used when the
vacuum pump is only capable of pumping down to 28in. of
mercury vacuum and the system does not contain any liquid water.
Refer to Fig. 90 and proceed as follows:
1 Pump the system down to 28in. of mercury and allow the
pump to continue operating for an additional 15 minutes.
2 Close the service valves and shut off vacuum pump.
3 Connect a nitrogen cylinder and regulator to the system and
open until the system pressure is 2 psig.
4 Close the service valve and allow the system to stand for 1
hr. During this time, dry nitrogen will be able to diffuse
throughout the system absorbing moisture.
5 Repeat this procedure as indicated in Fig. 90. The system
will then be free of any contaminants and water vapor.
CHECK FOR TIGHT, DRY SYSTEM
(IF IT HOLDS DEEP VACUUM)
EVACUATE
BREAK VACUUM WITH DRY NITROGEN
WAIT
EVACUATE
RELEASE CHARGE INTO SYSTEM
BREAK VACUUM WITH DRY NITROGEN
EVACUATE
WAIT
A95425
Fig. 90 – Triple Evacuation Method
Final Tubing Check
IMPORTANT:
Check to ensure the factory tubing on both the
indoor and outdoor unit has not shifted during shipment.
Ensure the tubes are not rubbing against each other or any
sheet metal. Pay close attention to the feeder tubes, ensuring
the wire ties on the feeder tubes are secure and tight.
START−UP
Test Operation
Perform the test operation after completing the gas leak and
electrical safety check.
1 Push ON/OFF on the remote control to begin testing.
NOTE: A protection feature prevents the air conditioner from
being activated for approximately 3 minutes.
2 Push MODE , select COOLING, HEATING, FAN mode
to check if all functions work correctly.
System Checks
1 Conceal the tubing where possible.
2 Ensure the drain tube slopes downward along its entire
length.
3 Ensure all tubing and connections are properly insulated.
4 Fasten the tubes to the outside wall, when possible.
5 Seal the hole through which the cables and tubing pass.
Indoor Unit
1 Do all the remote control buttons function properly?
2 Do the display panel lights work properly?
3 Does the air deflection louver function properly?
4 Does the drain work?
Outdoor Unit
1 Are there unusual noises or vibrations during operation?
Explain the Following Items to Customer with the Aid of the
Owner’s Manual:
1 How to turn air conditioner on and off; selecting
COOLING, HEATING and other operating modes;
setting a desired temperature; setting the timer to
automatically start and stop air conditioner operation; and
all other features of the remote control and display panel.
2 How to remove and clean the air filter.
3 How to set the air deflection louver.
4 Explain care and maintenance.
5 Present the Owner’s Manual and installation instructions to
customer.