3-5
(7) If water hammer may occur, attach a pressure damper (e.g.
accumulator).
(8) Observe the following points when installing the suction pipe
for the model VKN-e.
Do not allow the suction pipe to exceed 0.7 m in length
including its horizontal piping section. If you need to install a
longer suction pipe for a compelling reason, provide a
check valve with small head loss at the end of the suction
pipe.
Provide a sufficient distance from the end of the suction pipe
to the liquid level (La in the figure) and to the wall of the
tank (oil tank) (B in the figure). If the end position is too shallow or too close to the wall, vortex
may be formed, thus leading to the suction of air, making it impossible to pump the liquid, or
causing vibrations and noise.
Provide a sufficient distance from the end of the suction pipe to the bottom surface of the tank (oil
tank) (Lb in the figure). If the end position is too close to the bottom surface, it may lead to suction
failure or the suction of foreign matter such as cutting powder.
To prevent the formation of air pockets inside the pipe, provide a rising slope leading up to the
pump.
(9) If there is an upward curve on the discharge pipe, ensure that air can be vented from the section.
(10) If you provide a relief pipe on the discharge side of the pump, also provide a sluice valve in the
middle of the relief pipe to adjust the relief volume.
Note
If the amount of liquid released from the relief pipe is too much, the liquid
temperature easily rises in the tank (oil tank).
(11) On completion of the piping work, be sure to clean the tank (oil tank). Pay attention not to
contaminate the system with foreign matter.
3.5 Precautions for wiring work
Danger
Use high-quality wiring equipment and devices, 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 electrical wiring work. Unqualified persons are prohibited by
law to carry out wiring work, and it is very dangerous.
Danger
Securely connect the terminals of the power cable. Loose terminals may
cause the motor to run in open-phase condition, thus leading to motor
burnout.
(1) For the size of the power cable, refer to the following:
Model
Minimum size of the cable
(200-volt class)
VKN115A-e, VKP115A-e
1.6 mm
(2) Be sure to install a ground fault interrupter and an overload protection device on the primary
power side of the pump.
* The starting current of Top Runner Energy Efficiency Standards (equivalent to IE3)
motor-equipped products tends to become higher than that of standard efficiency (IE1)
motor-equipped products. Therefore, when you switch from an IE1 motor-equipped product, it is
necessary to verify the applicability of its ground fault interrupter and overload protection device.
最大吸込配管長さ0.7m以下
Max. suction pipe length: 0.7 m
(As short as possible with
minimal upward curve)
Horizontal piping
Pump
Pipe support
