50
PIPING AND WIRING FOR INDOOR UNIT
ENGLISH
Water Charging
For water charging, please follow below procedures.
Step 1. Open all valves of whole water circuit. Supplied water should be charged not only inside
the indoor unit, but also in the under floor water circuit, sanitary water tank circuit, FCU
water circuit, and any other water circuits controlled by the product.
Step 2. Connect supply water into drain valve and fill valve located at the side of the shut-off
valve.
Step 3. Start to supply water. While supplying water, following should be kept.
- Pressure of supplying water should be 2.0 bar approximately.
- For supplying water pressure, time to be taken from 0 bar to 2.0 bar should be more
than 1 minute. Sudden water supply can yield water drain through safety valve.
- Fully open the cap of air vent to assure air purging. If air is exist inside the water circuit,
then performance degrade, noise at the water pipe, mechanical damage at the surface
of electric heater coil.
Step 4. Stop water supplying when the pressure gauge located in front of the control panel
indicates 2.0 bar.
Step 5. Close drain valve and fill valve. Then wait for 20~30 seconds to observe water pressure
being stabilized.
Step 6. If following conditions are satisfactory, then go to step 7(pipe insulation). Otherwise, go
to step 3.
- Pressure gauge indicates 2.0 bar. Note that sometimes pressure in decreased after step
5 due to water charging inside expansion vessel.
- No air purging sound is heard or no water drop are popping out from air vent.
Pipe Insulation
Purpose of water pipe insulation is :
- To prevent heat loss to external environment
- To prevent dew generation on the surface of the pipe in cooling operation
Water cycle
* For the water pipe system, use the closed loop type.
1. For the parts of the water pipe system, use the parts above the design water pressure.
2. For the water pipe, do not use steel pipe.
3. To replace the connected device easily, install the union joint (2).
4. Install the service port (3) to clean the heat exchanger at each inlet and outlet of the water
pipe.
5. Always install a strainer (4) at the inlet of the water pipe.
- For the strainer, use one with 28 mesh or above with measurement diameter of 0.4mm or
less. (Exclude other net)
- Always install the strainer on the horizontal pipe.
(When dirt, trash, rusted pieces get into the water pipe system, it can cause problems to the
product by corroding the metallic material.)
No water-leakage permitted at the drain and fill valve. Leakage-proof treatment which is
described in previous section should be applied.
CAUTION
!