Opening The Shut-Off Valves; Hot Water Piping Work Of The Ghp Outdoor Unit - Panasonic U-20GES3E5 Manual Del Usuario

4. OPENING THE SHUT-OFF VALVES

Ball valves are used for the shut-off valves on the outdoor units. Each can be opened and closed by rotating
the tab 90 degrees.
Follow the procedure below to securely open the valves.
1. Remove the cap.
2. Slowly and securely turn the tab to the left
(counterclockwise) 90 degrees.
The valve is fully open when the tab has
been rotated 90 degrees (when it contacts
the stopper). Do not forcefully attempt to
turn the tab past this point.
The gas tube shut-off valve of the
U-10MES2E8 outdoor unit is fully opened
by turning it fully to the left, using a
hexagonal wrench (8 mm across faces).
The liquid tube shut-off valve is fully
opened by turning it fully to the left, using a
hexagonal wrench (4 mm across faces).
Be sure to open the shut-off valve all the way.
3. Reattach and tighten the cap.
Table 9
Unit type Tube
Gas
U-20GES3E5 Liquid
Balance
Gas
U-10MES2E8 Liquid
Balance

5. HOT WATER PIPING WORK OF THE GHP OUTDOOR UNIT

Precautions on Hot Water Piping Work
CAUTION
• The allowable pressure for the hot water piping in the outdoor unit is 0.7 MPa.
• Attach water release valves and air release valves to the hot water piping at the appropriate locations. If air
becomes mixed with the fluid in the pipe, this could result in noise, corrosion, or reduced performance.
• Use a hot water circulation rate in the range from 35ℓ/min to 51ℓ/min.
If a circulation rate outside this range is used, this could result in a breakdown or air blockage in the pipe
due to corrosion or freezing of the heat exchanger.
• Be sure to fully perform the heat-retention work for DHW piping.
Failure to provide adequate heat retention will result in heat loss. This could also result in damage due to
freezing during periods of extreme cold.
• Attach the pump for DHW to the inlet piping side for DHW.
• For the DHW piping, select pipes with a connection port diameter of 27.2 mm or larger, and pay careful
attention to the flow rate. Route the piping by minimizing bends and pipe resistance, and use union joints
and similar parts near the outdoor unit so that the outdoor unit can be easily separated.
• Attach a strainer (80 mesh or higher) to the outdoor unit inlet pipe for protecting the DHW heat exchanger
in the outdoor unit. Also attach valves before and after the strainer and at the outlet pipe for maintenance
and servicing.
• Attach a temperature gauge and pressure gauge to the piping. These are needed for conducting checks of
the operation status and for maintenance.
Cap tightening torque [N · m]
30±3
30±3
22.5±2.5
50±3
24.5±3.9
22.5±2.5
EN - 25
Rotate the tab 90 degrees.
Fully closed Fully open
Gas tube, Liquid tube
Fully closed Fully open
Balance tube
Fig. 22 Rotating the Tab