Units With An External Water Pump; Units With A Built-In Water Pump; Electrical Power Supply; Unbalance In Power Supply Voltage - Daikin EWYD-BZ Series Installation, Maintenance & Operation Manual

Before putting the machine into operation, clean the water circuit. Dirt, scaling, corrosion residue and other foreign
material can accumulate in the heat exchanger and reduce heat transfer capacity. Pressure drops can also increase,
consequently reducing water flow. Thus, correct water treatment reduces the risk of corrosion, erosion, scaling, etc. The
most appropriate water treatment must be established locally according to the type of installation and local
characteristics of the process water.
The manufacturer is not responsible for damage or bad operation of the apparatus resulting from failure to treat water or
from incorrectly treated water.

Units with an external water pump

Start the water pump and check the water system for any leaks; repair these if necessary. While the water pump is in
operation, adjust the water flow until the design pressure drop for the evaporator is reached. Adjust the flow switch
trigger point (not factory-supplied), to ensure operation of the machine within a  20% flow range.

Units with a built-in water pump

This procedure foresees factory installation of the optional single -or twin- water pump kit.
Check that switches Q0, Q1 and Q2 are in the open position (Off or 0). Also check that the thermal-magnetic switch Q12
in the electrical panel control area, is in the Off position.
Close the general Q10 door-block switch on the main board and move the Q12 switch to the On position.
From this moment onwards, the machine will be under electrical power. Use
operation.
A lack of attention during subsequent operation may cause serious personal injury.
Single pump To start the water pump, turn the Q0 switch to the On (or 1) position and wait for the unit On message
to appear on the display. Adjust the water flow until the evaporator design pressure drop is reached. Adjust the flow
switch (not included) at this point, to ensure that the machine operates within a  20% flow range.
Twin pump The system foresees the use of a twin pump having two motors, each as a backup to the other. The
microprocessor enables one of the two pumps with a view to minimising the number of hours and start-ups. To start one
of the two water pumps, turn the Q0 switch to the On (or 1) position and wait for the unit On message to appear on the
display. Adjust the water flow until the evaporator design pressure drop is reached. Adjust the flow switch (not included)
at this point, to ensure that the machine operates within a  20% flow range. To start the second pump, keep the first one
on for at least 5 minutes, then open the Q0 switch, wait for the first pump to turn off. Close the Q0 switch again to start
the second pump.
Using the microprocessor keypad it is possible, however, to set pump start-up priorities. Please see the
microprocessor manual for the relevant procedure.

Electrical power supply

The machine's power supply voltage must be the same as that specified on the nameplate  10% while the voltage
unbalance between phases must not be in excess of  3%. Measure the voltage between phases and if the value does
not fall within the established limits, correct it before starting the machine.
Provide suitable power supply voltage. Unsuitable power supply voltage could cause malfunction of the control
components and undesired triggering of the thermal protection devices, along with a considerable reduction in the life of
the contactors and electric motors.

Unbalance in power supply voltage

In a three-phase system, excessive unbalance between the phases causes overheating of the motor. The maximum
allowed voltage unbalance is 3%, calculated as follows:

V
MAX
Unbalance %:
V
AVG
AVG = average
Example: the three phases measure respectively 383, 386 and 392 Volts, the average is:
 
383 386 392

V
387
3
D-EIMHP00508-16EN - 44/64
V
AVG
x 100 _____ %
IMPORTANT
CAUTION
ATTENTION
extreme caution during subsequent