Connecting Pipes - Mitsubishi Electric City Multi PUHY-P-YKB-A1 series Installationshandbuch

9-5-1. Removing the pinched connecting pipes
The unit is shipped with the pinched connecting pipes attached to the liquid- and gas-side service valves to prevent
gas leakage.
Take the following steps ① through ③ to remove the pinched connecting pipes before connecting refrigerant pipes to
the outdoor unit.
① Check that the service valves are fully closed (turned clockwise all the way).
② Remove the gas in the pinched connecting pipes, and drain out all the refrigerant oil. (See Ⓔ below.)
③ Remove the pinched connecting pipes. (See Ⓕ below.)
<A> <B>
Ⓒ
Ⓐ
Ⓓ
O S
Ⓕ
Ⓔ

9-5-2. Connecting pipes

・The refrigerant pipe from the outdoor unit is branched at the pipe end, and each branch is then connected to an
indoor unit.
Indoor unit
Gas pipe
Outdoor unit
Liquid pipe
Branched section
・Refer to section 5 "Package contents" for details about the supplied connecting pipes.
・When connecting pipes, make sure the service valves are completely closed.
・Commercially available pipes often contain dust or debris. Always blow them clean with a dry inert gas.
・Take care to prevent dust, water or other contaminants from entering the pipes during installation.
・Reduce the number of bending portions as much as possible, and make the bending radius as big as possible.
・Do not use any commercially available anti-oxidizing agents since they may cause pipe corrosion and degrading of
the refrigerant oil. Please contact Mitsubishi Electric for more details.
・Make sure that the pipes are not in contact with each other, unit panels, or base plates.
(1) When routing the pipes through the front of the unit
<A> <B>
<A> Liquid side
<B> Gas side
Refrigerant service valve piping
Ⓐ
KD79S703H01
<A> Refrigerant service valve (liquid/brazed)
<B> Refrigerant service valve (gas/brazed)
Valve shaft
Ⓐ
The unit is shipped with the valve closed. Keep the valve closed while connecting pipes or
evacuating the system. Open the valve upon completion of this work.
Turn the shaft counterclockwise as far as it will go (90˚) to open the valve, and clockwise to close
it.
Stopper pin
Ⓑ
Ⓑ Prevents the shaft from turning 90˚ or more.
Ⓒ
Service port
Ⓒ
Through the service ports, you can charge refrigerant, remove the gas in the pinched connecting
pipes, or evacuate the system.
Cap
Ⓓ
Remove the cap before turning the shaft. Put the cap back on upon completion of all work.
Severed section of the pinched connecting pipe
Ⓔ
Brazed section of the pinched connecting pipe
Ⓕ
Connecting method
Brazed or flared
Brazed
Brazed
Brazed
Ⓐ
(2) When routing the pipes through the bottom of the unit
<A> <B>
GB-24
Ⓐ