Startup Procedure; Turning On The Machine; Table 3 - Typical Working Conditions With Compressors At 100 - Daikin EWYD-BZ Series Installation, Maintenance & Operation Manual

Startup procedure

Turning on the machine

1. With the general switch Q10 closed, check that switches Q0, Q1, Q2 and Q12 are in the Off (or 0) position and the
Q8 switch is in the requested position.
2. Close the thermal-magnetic switch Q12 and wait for the microprocessor and the control to start. Check that the oil
temperature is warm enough. The oil temperature must be at least 5 °C above the saturation temperature of the
refrigerant in the compressor.
If the oil is not warm enough, it will not be possible to start the compressors and the phrase "Oil Heating" will appear
3.
on the microprocessor display.
4. Start the water pump should the machine not be supplied with one.
Put the Q0 switch on the On position and wait for "Unit-On/ Compressor Stand-By" to appear on the display.
5.
6. If the water pump is supplied with the machine, the microprocessor should start it at this point.
7. Check that the water heat exchanger pressure drop is the same as the design pressure drop and correct if
necessary. The pressure drop must be measured at the factory-supplied charge connections placed on the
evaporator nozzles. Do not measure the pressure drops at points where any valves and/or filters are interposed.
8. Only at the first start-up, put the Q0 switch in Off position to check that the water pump stays on for three minutes
before it stops (this applies to the built-in pump and any external pump).
9. Put the Q0 switch in On position once again.
10. Check that the local temperature setpoint is set to the required value by pressing the Set button.
11. Turn the Q1 switch to On (or 1) to start compressor #1.
12. Once the compressor has started, wait for at least 1 minute for the system to stabilise. During this time the controller
will perform a series of operations to empty the evaporator (Pre-Purge) to ensure a safe start-up.
13. At the end of the Pre-Purge, the microprocessor will start loading the compressor, now running, in order to reduce
the outlet water temperature. The correct functioning can be verified by checking the supply frequency and the
current supplied by the VFD.
14. Check refrigerant evaporation and condensation pressure.
15. Check that the cooling fans have started, as a response to an increase in condensation pressure (chiller mode).
16. Check the circuit operating parameters by verifying:
Superheating of refrigerant at compressor suction
Superheating of refrigerant at compressor discharge
Subcooling of liquid coming out of the condenser banks
Evaporation pressure
Condensation pressure
Except for liquid temperature, which requires the use of an external thermometer, all other measurements can be
carried out by reading the relevant values directly on the on-board microprocessor display.
17. Turn the Q2 switch to On (or 1) to start compressor #2.
18. Repeat steps 10 through 15 for the second circuit.

Table 3 - Typical working conditions with compressors at 100%

Mode
Chiller
Heat pump
The symptoms of a low refrigerant charge are:

low evaporation pressure

high suction and discharge superheating (outside the aforesaid limits)

Low super-cooling value
In this case, add R134a refrigerant to the relevant circuit. The system has been provided with a charge connection
between the expansion valve and the evaporator. Charge refrigerant until working conditions return to normal.
Remember to reposition the valve cover when finished.
19. To turn off the machine temporarily (daily or weekend shutdown) turn the Q0 switch to Off (or 0) or open the remote
contact between terminals 58 and 59 on terminal board M3 (Installation of remote switch to be carried out by the
customer). The microprocessor will activate the shutdown procedure, which requires several seconds. Three
minutes after the compressors have been shut down, the microprocessor will shut down the pump. Do not switch off
the main power supply so as not to de-activate the electrical resistances of the compressors and the evaporator.
D-EIMHP00508-16EN - 46/64
Suction superheating
4  6 °C
6  9 °C
IMPORTANT
Discharge superheating
20  25 °C
25  30 °C
Liquid subcooling
3  6 °C
2  5 °C