User`s manual

6-5
(3) Safeguard from lightning
Below are countermeasures in case when the factory facilities are located far from residential
areas and that effects from induced lightning (induced voltage by lightning strikes) are expected.
Note, however, that they are not the measures for direct strikes of lightning. In some cases, the
voltage of the induced lightning may go beyond 4000 KV. Therefore, the purpose of these
countermeasure is just to minimize the damage on the device.
Countermeasure 1: Install a surge absorber on the receiver panel of commercial electric power as
protection from induced lightning.
Different models should be chosen according to the facilities load and power
supply voltage. For your reference, below is a wiring diagram of the outdoor
type cubicle for 1.7 KVA.
Note: Note the following when wiring.
- The ground of the surge absorber is the special class-D ground (less than 10-ohm ground
resistance) and should be separated from the ground of the JW300 (Class-D grounding.)
- Install the main breaker before the surge absorber.
- The followings are known surge absorbers in the market. Different types for different power
supply voltages.
- Use the ground wire of over 3.5mm
2
sectional area for the surge absorber.
Factory
AC input
Class-D grounding
AC100V
250 VAC input
PLC
Breaker
Surge absorber
Main breaker
30A
Transformer
(for voltage reduction)
Ground
For other
device
U
V
E
Special class-D grounding (less than 10 ohm)
Specifications
Varister voltage: 250V –10%
Surge resistant volume:
5,000A (8/20 ms)
Energy resistant volume: 90 Joule
Varister voltage: 500V –10%
Surge resistant volume:
5,000A (8/20 ms)
Energy resistant volume: 150
Joule
Commercial
power voltage
100 VAC
200 VAC
Manufacturer
Matsushita
Electric Co.,Ltd.
Model name
ERZ-A20PK251
ERZ-A20PK501