Page 30
CAUTION
DO NOT
mix refrigerant types.
6.
Close the Low Pressure side of the manifold
gauge, and turn off the vacuum pump.
7.
Wait for 5 minutes, then check that there
has been no change in system pressure.
8.
If there is a change in system pressure, refer
to Gas Leak Check section for information
on how to check for leaks. If there is no
change in system pressure, unscrew the cap
from the packed valve (high pressure valve).
9.
Insert hexagonal wrench into the packed valve
(high pressure valve) and open the valve by
turning the wrench in a 1/4 counterclockwise
turn. Listen for gas to exit the system, then
close the valve after 5 seconds.
10.
Watch the Pressure Gauge for one minute
to make sure that there is no change in
pressure. The Pressure Gauge should read
slightly higher than atmospheric pressure.
For R290 refrigerant unit, the total amount of refrigerant to be charged is no more than:
387g(<=9000Btu/h), 447g(>9000Btu/h and <=12000Btu/h), 547g(>12000Btu/h and <=18000Btu/h),
632g(>18000Btu/h and <=24000Btu/h)
.
Flare nut
Cap
V
alve body
V
alve stem
11.
Remove the charge hose from the service port.
12.
Using hexagonal wrench, fully open both the
high pressure and low pressure valves.
13.
Tighten valve caps on all three valves (service
port, high pressure, low pressure) by hand.
You may tighten it further using a torque
wrench if needed.
OPEN VALVE STEMS GENTLY
When opening valve stems, turn the hexagonal
wrench until it hits against the stopper. Do not
try to force the valve to open further.
Note on Adding Refrigerant
ADDITIONAL REFRIGERANT PER PIPE LENGTH
Connective Pipe
Length (m)
Air Purging
Method
Additional Refrigerant
< Standard pipe length Vacuum Pump
N/A
> Standard pipe
length
Vacuum Pump
Liquid Side: Ø 6.35 (ø 0.25”)
R32:
(Pipe length – standard length) x 12g/m
(Pipe length – standard length) x 0.13oZ/ft
R290:
R290:
(Pipe length – standard length) x 10g/m
(Pipe length – standard length) x 0.10oZ/ft
Liquid Side: Ø 9.52 (ø 0.375”)
R32:
(Pipe length – standard length) x 24g/m
(Pipe length – standard length) x 0.26oZ/ft
(Pipe length – standard length) x 18g/m
(Pipe length – standard length) x 0.19oZ/ft
Fig. 6.2
Some systems require additional charging depending on pipe lengths. The standard pipe length varies
according to local regulations. For example, in North America, the standard pipe length is 7.5m (25’).
In other areas, the standard pipe length is 5m (16‘). The refrigerant should be charged from the
service port on the outdoor unit’s low pressure valve. The additional refrigerant to be charged can be
calculated using the following formula:
R410A:
R410A:
(Pipe length – standard length) x 15g/m
(Pipe length – standard length) x 0.16oZ/ft
(Pipe length – standard length) x 30g/m
(Pipe length – standard length) x 0.32oZ/ft
Page 31
Electrical and Gas Leak Checks
8
Electrical Safety Checks
After installation, confirm that all electrical wiring
is installed in accordance with local and national
regulations, and according to the Installation
Manual.
BEFORE TEST RUN
Check Grounding Work
Measure grounding resistance by visual detection
and with grounding resistance tester. Grounding
resistance must be less than 0.1
Ω
.
Note:
This may not be required for some
locations in the US.
DURING TEST RUN
Check for Electrical Leakage
During the
Test Run,
use an electroprobe and
multimeter to perform a comprehensive electrical
leakage test.
If electrical leakage is detected, turn off the unit
immediately and call a licensed electrician to find
and resolve the cause of the leakage.
Note:
This may not be required for some
locations in the US.
Gas Leak Checks
There are two different methods to check for gas
leaks.
Soap and Water Method
Using a soft brush, apply soapy water or liquid
detergent to all pipe connection points on the
indoor unit and outdoor unit. The presence of
bubbles indicates a leak.
Leak Detector Method
If using leak detector, refer to the device’s
operation manual for proper usage instructions.
AFTER PERFORMING GAS LEAK CHECKS
After confirming that the all pipe connection
points DO NOT leak, replace the valve cover on
the outside unit.
WARNING – RISK OF
ELECTRIC SHOCK
ALL WIRING MUST COMPLY WITH LOCAL
AND NATIONAL ELECTRICAL CODES,
AND MUST BE INSTALLED BY A LICENSED
ELECTRICIAN.
