4-3
4.3
Precautions for wiring work
Warning
Use the wiring equipment and devices compliant to use conditions, and
carry out wiring work safely and securely according to the technical
standards for electrical facilities, as well as the indoor wiring
regulations.
Only qualified personnel such as licensed electrical engineers are
allowed to carry out electric wiring work.
Incomplete wiring work by unqualified persons is prohibited by law.
4.3.1
Wiring work for power supply
Warning
Be sure to install a ground fault interrupter dedicated to this unit at the
primary power supply. Otherwise, it may lead to an electric shock
and/or fire.
Warning
Ensure to securely install a ground wire to the control panel. Ensure to
perform grounding work.
Warning
Connecting a ground wire to gas or water pipes is not only prohibited
by law but also extremely dangerous.
Caution
Do not install different or other cables or control wires in one pipe or
conduit.
Caution
Do not attach a phase advance capacitor to the secondary wiring of the
control panel.
Otherwise, it may lead to failures in the inverter or the phase advance
capacitor.
(1) On the primary power supply side of the water supply unit, be sure to install a ground fault interrupter
dedicated to this unit.
Check the capacity of the ground fault interrupter fitted inside the control panel, and then select a ground
fault interrupter on the power supply side in consideration of protection coordination.
(2) Be sure to attach a ground wire to prevent an electric shock.
Connect the ground wire to the ground terminal inside the control panel.
(3) Connect the primary power line to the power terminal block inside the control panel.
Pass each wire through a metal tube or a metal conduit for shielding, and ground the covering of the tube.
(4) Control the fluctuation of the voltage within ±10% of the rated voltage, and the frequency within ±5% of the
rated frequency.
Keep in mind that if you use the unit at a voltage or frequency out of the range, the unit may break down.
Also note that if the power voltage is lower than the rated voltage, an overload may occur even if the flow
rate is within the specified range.
(5) Before running the pump, check the following points again:
x
An appropriate ground fault interrupter is installed.
x
Wiring is correct.
x
The unit is securely grounded.
x
None of the three wires (two wires for single-phase power) of the motor has come loose or is
disconnected.
Note that poor or incorrect connection of motor terminals may burn out the motor.
