28
Wiring
Surge voltage
The electronic circuit in the control unit may fail due to a surge voltage. Do not place the
pump close to a high power device of 200V or more which may generate a large surge
voltage. Otherwise, take any of the following measures.
• Install a surge absorption element (such as a varistor with capacity of 2000A or more)
via power cable or,
Recommended varisters. See manufacturer's catalogues for detail.
Panasonic ERZV14D431
KOA
NVD14UCD430
•
A noise cut transformer via the power cable.
Precautions for ON-OFF control by a mechanical relay
The control unit is equipped with a CPU. Always start/stop the pump by the STOP signal
for ON-OFF control. Try not to turn on and off the main power. Otherwise, observe the
following points.
• Do not turn ON/OFF power voltage more than six times per hour.
• When using a mechanical relay for ON-OFF operation, its contact capacity should be
5A or more. Contact point may fail if it is less than 5A.
• If a mechanical relay with the contact capacity of 5A is used, the maximum allowable
ON/OFF operation is about 150,000 times. The contact capacity should be 10A or more
when making ON-OFF operation over 150,000 times or sharing a power source with a
large capacity equipment. Otherwise a contact point may fail by surge voltage.
• Use a solid state relay (SSR) as necessary (such as the OMRON G3F). See manufac-
turer's catalogues for detail.
Signal wire connection
Check that power voltage is turned off. The pump is still charged right after turning off power. Wait for one
minute before wiring.
Applicable cables
Cable outer diameter: 7.6-7.8mm.
Cable type: VCTF-4 0.75mm² four-core cable
VCTF-3 1.25mm² triplex cable
UL/CSA SJT 18AWG/2 duplex cable
* The use of a cable with a smaller O.D. can break a connection point of the cable or impair water-/dust-tightnesse of the pump.
Surge absorption element
Noise cut transformer
Summary of Contents for EHN-B11-NAE
Page 67: ...67 Specifications ...
