Pioneer WYT Inverter Series Installation & User Manual page 37

Outdoor Unit Installation Instructions
Air Evacuation and Bleeding the Circuit
The air and/or humidity left inside the refrigeration circuit can contaminate the refrigerant
and cause abnormal spikes in pressure, leading to eventual compressor malfunction.
Therefore, after having connected the indoor and outdoor units to create a closed system, it is
necessary to bleed the air and humidity out of the circuit by using a vacuum pump.
Evacuation should be performed upon initial installation or when the unit is relocated.
BEFORE PERFORMING EVACUATION
 Check to make sure that both high-pressure
and low-pressure pipes between the indoor
and outdoor units are connected properly
in accordance with the "Refrigerant Piping
Connection" section of this manual.
 Check to make sure all wiring is connected
properly.
Evacuation Instructions
Before using a vacuum pump and manifold gauge,
read their operation manuals to become familiarized
with using them properly.
1) Unscrew and remove the caps from the
2-way and 3-way valves.
2) Unscrew and remove the cap from the
service port.
3) Connect the blue (low) hose of the
manifold gauge to service port on the
outdoor unit's 3-way valve (use an
adapter if needed). Ensure that the pin
fully engages the Schrader valve.
4) Connect the yellow (middle) hose from the
manifold gauge to the vacuum pump.
5) Open the low-pressure valve of the manifold
gauge. Keep the high-pressure valve closed.
Service Port
Refrigerant Flow Direction
3-way Valve
Valve Cap
[1] Turn
Manifold Gauge
Low-Pressure Gauge High-Pressure Gauge
Low-Pressure
High-Pressure
Valve
Blue (Low) Hose
3-Way Valve
7
Vacuum Pump
Step 1
Indoor Unit
2-way
Valve
Valve Cap
[1] Turn
Service
Port Nut
[2] Turn
Step 3-5
Valve
Yellow (Middle) Hose
Vacuum Pump
Page 37

3-Way
Valve
