Multizone Outdoor Unit Installation Manual
Revised 5/14/2020
8. Test Vacuum Let lineset sit in vacuum and
watch for rise in the gauge over 15 - 30 min-
utes. A slow rise is normal. If the gauge stays
below 500, proceed to next step. If a leak is
suspected, repeat Step 8. If moisture is sus-
pected, breaking vacuum with dry nitrogen
to 5 psi may help remove the moisture. Once
vacuum test is complete, follow the next step
to release refrigerant into Zone A.
9. Release refrigerant (See Fig. 9.3) Release re-
frigerant into the lineset by opening the larger
(gas side, or suction) lineset valve fully. Then
open the smaller (liquid side) lineset valve
fully. NOTE: do not force valves open past
the point it stops turning under normal hand
pressure.
10. Repeat for each zone Disconnect your gaug-
es and attach to lineset valve B. Repeat steps
2 - 10 for each remaining zone in sequence.
11. Test Run Once you complete the vacuum test
on the last zone, leave the gauges in place.
Follow the remaining steps to test run the
system, and add refrigerant if needed.
12. Record Pressure Start the unit in cooling-
mode. Run for 10 minutes and monitor oper-
ating pressure reading. Power down the unit
and wait 5 minutes. Remove the low pressure
gauge and attach the high pressure gauge to
the service port. Change to Heat mode and
restart. Run for 10 minutes and monitor the
operating pressure. Normal pressure will vary
based on outside temperature and cooling
vs. heating mode. Enter both results in the
adjacent chart. Completing this step on rst
startup will provide information in case trou-
bleshooting is required.
13. Add refrigerant (if needed) Depending on
lineset length and the conguration of your
system, you may need to add refrigerant. Use
Table 9.1 on the next page to calculate the
amount, if any, to add to your system.
Note: The system must be running in cooling
mode as you add refrigerant.
Air Evacuation
Page 21
Flare nut
Cap
Valve body
Valve stem
Fig 9.3
Cooling Mode Pressure Reading
psi
Heat Mode Pressure Reading
psi
Record Pressure Readings here