Midea MFEP26VA-N User Manual page 32

Flare nut
valve body
valve stem
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
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. For the R290 refrigerant models, no refrigerant can be
added. The additional refrigerant to be charged can be calculated using the following formula:
ADDITIONAL REFRIGERANT PER PIPE LENGTH
Connective Pipe Air Purging
Length (m)
< Standard pipe length Vacuum Pump
> Standard pipe
length
Vacuum Pump
DO NOT MIX REFRIGERANT TYPES.
Step 2：
●
●
●
Cap
●
●
●
Method
Liquid Side: Ø 6.35 (1/4")
(Pipe length – standard length) x 15g/m
(Pipe length – standard length) x 0.16oZ/ft (Pipe length – standard length) x 0.32oZ/ft
(Pipe length – standard length) x 12g/m
(Pipe length – standard length) x 0.13oZ/ft (Pipe length – standard length) x 0.26oZ/ft
(Pipe length – standard length) x 20g/m
(Pipe length – standard length) x 0.21oZ/ft (Pipe length – standard length) x 0.42oZ/ft
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).
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.
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.
Remove the charge hose from the service port.
Using hexagonal wrench, fully open both the high
pressure and low pressure valves.
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.
Additional Refrigerant
N/A
R410A:
R32:
R22:
30
Liquid Side: Ø 9.52 (3/8")
R410A:
(Pipe length – standard length) x 30g/m
R32:
(Pipe length – standard length) x 24g/m
R22:
(Pipe length – standard length) x 40g/m