Selecting An Operating Mode; Shutdown For A Long Time; Starting Up After Seasonal Shutdown - Daikin EWYD-BZ Series Installation, Maintenance & Operation Manual

If the machine is not supplied with a built-in pump, do not shut down the external pump before 3 minutes have elapsed
after the last compressor has shut down. Early shutdown of the pump triggers a water-flow failure alarm.

Selecting an operating mode

The chiller operating mode (water cooling) is selected by setting the Q8 switch in 0 (or off) position, while the heat pump
operating mode (water heating) is selected by setting the Q8 switch in 1 (or on) position.
The switch can be made either with the compressors in motion or turned off with the unit on or off (Q0 switch on 0 or off).
In the first two instances, the unit will be turned off by the controller and kept turned off for an amount of time that can be
set, to be checked (factory-setting 5 minutes) and then restarted in the desired operating mode.

Shutdown for a long time

1. Turn switches Q1 and Q2 to the Off (or 0) position to shut down the compressors, using the normal pump-down
procedure.
2. After the compressors have been shut down, turn switch Q0 to Off (or 0) and wait for the built-in water pump to shut
down. If the water pump is managed externally, wait for 3 minutes after the compressors have shut down before
turning off the pump.
3. Open the Q12 (Off position) thermal magnetic switch inside the control section of the electrical board then open the
general disconnector switch Q10 to cut off the machine's power supply entirely.
4. Close the compressor intake valves (if any) and delivery valves and also the valves located on the liquid and liquid
injection line.
5. Place a warning sign on every switch that has been opened, advising to open all the valves before starting the
compressors.
6. If no water and glycol mixture has been introduced into the system, discharge all the water from the evaporator and
from the connected piping if the machine is to remain inactive during the winter season. One must remember that
once the machine's power supply has been cut off, the antifreeze electrical resistance cannot function. Do not leave
the evaporator and piping exposed to the atmosphere during the entire period of inactivity.

Starting up after seasonal shutdown

1. With the general disconnector switch open, make sure that all the electrical connections, cables, terminals and
screws are well tightened to ensure good electrical contact.
Verify that the power supply voltage applied to the machine is within  10% of the nominal nameplate voltage and
2.
that the voltage unbalance between phases is within  3% range.
3. Verify that all control devices are in good condition and functioning and that there is a suitable thermal load for start­
up.
4. Verify that all the connection valves are well tightened and that there are no refrigerant leaks. Always reposition the
valve covers.
5. Verify that switches Q0, Q1, Q2 and Q12 are in the open position (Off). Turn the general disconnector switch Q10 to
the On position. Doing this will allow to turn on the electrical resistances of the compressors. Wait at least 12 hours
for them to warm up the oil.
6. Open all suction, delivery, liquid and liquid injection valves. Always reposition valve covers.
7. Open the water valves to fill the system and vent the air from the evaporator through the vent valve installed on its
shell. Verify that there are no water leaks from the piping.
IMPORTANT
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