surge protectors

[journeymenelctric@msn.com]

Do surge protectors at a service entrance have to have a disconnecting means of their own? For example: Can you put an unfused tvss, with #2 AWG wires on the load side of a 400 amp disconnect without additional fuse protection.

 

[George Stolz]

See 285.21(A)(1).

 

[Jim W in Tampa]

Usually yes,its actually better that way.The #2 sounds bit high.Most isse have #10

 

[journeymenelctric@msn.com]

So according to your code reference the only overcurrent protection required is on the line side not on the load side of the disconnect.

 

[George Stolz]

I'd say it needs a service disconnect unless it's listed otherwise.

 

[Lxnxjxhx]

I couldn't find a surge prot. good for more than 20 A.
Can you post a link to the type you're talking about?

 

[journeymenelctric@msn.com]

Surge Suppressor

Surge Suppressor

www.apttvss.com Using the XGA series

 

[Lxnxjxhx]

XGA series

XGA series

Thanks. They seem to be an MOV controlling a relay.

 

[tom baker]

When you need a disconnect is driven by the mfgs instructions, unless its wired to a service disconnect.
Most do as the TVSS can short and needs OCP at its source. The Levitons I install use a 30 Amp OCP.

 

[brian john]

There are two types, primary and secondary TVSS's one needs protection and one does not. This was explained to me by a factory rep as to why a factory installed suppressor had no OCP this was on the line side of the main.

As for conductors size..I am no engineer but as this was explained to me bigger is better.

http://www.megavolt.co.il/Tips_and_info/surgeprotector2.html

 

[George Stolz]

Bear in mind, if OCPD is required, then it need not worry about the six handle rule. ( related discussion)