Refrigerant Connection - DeDietrich UME 20 Installation And Service Manual

Tapered nut
Indoor unit
Wrenches
Connection
External diameter of the pipe
(mm/inch)
Ø 6.35 – 1/4
Ø 9.52 – 3/8
Ø 12.7 – 1/2
Ø 15.88 – 5/8

Leak test
- Check that the valve on the outdoor unit closes.
- Connect the pressure gauge and the nitrogen canister to the Schrader type valve, then gradually pressurise
the refrigerant connection pipes and the indoor module to 35 bar, in 5 bar increments.
- Check the leak-tightness of all the connections using a leak detector aerosol. If leaks occur, repeat the steps
in order and check the leak-tightness again.
- Release the pressure and discharge the nitrogen.

Creating a vacuum
- Check that the stop valve is closed.
- Connect the vacuum gauge and the vacuum pump to the valve's service connector.
- Create the vacuum in the indoor module and the refrigerant connection pipes.
- Check the pressure against the recommendation table below:
Outdoor temperature
Absolute pressure target
Vacuum creation time once the
target pressure has been
reached
- Close the valve between the vacuum gauge/vacuum pump and the stop valve.
- Open the valves immediately after switching off the vacuum pump.
20180803 CR v3

Refrigerant connection

Pipe
Torque wrenches
Torque load
External diameter of the cone
fitting (mm)
17
22
26
29
°C >20 10
Pa 1000 600
bar 0.01 0.006
h 1 1
Outdoor unit
Torque wrenches
0 -10
250 200
0.0025 0.002
2 3
Liquid pipe
Gas pipe
Torque load (N.m)
14 - 18
34 - 42
49 - 61
69 - 82
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