A Little Confusion on Surge Arresters

You can please explain from this diagram. Are those cables separate items for purchase?

You have to procure earthing conductor (ECC) and fabricate earth pit, surge arrester supplier will not arrange these for you.

Your picture #1 is a pole mounted transformer and I am seriously doubtful that this would be the case in a T&D substation.

Picture #2 is barely symbolic, instead of fuse you will encounter CB and Isolator, as a standard practice you cannot common transformer and arrestor ground conductors and I expect that in a T&D substation the arrester will be separately mounted on a post / structure instead of transformer frame.

You can check the websites of prominent manufacturers like ABB, SIEMENS, Alsthom GE etc. to see the immages. Just go to www.google.com and make a search for the surge arrester.

Thanks for the info on the earthing conductor, maybe that's what the clients mean by "surge arrester earthing". " You can check the websites of prominent manufacturers like ABB, SIEMENS, Alsthom GE etc. to see the immages. Just go to www.google.com and make a search for the surge arrester." ...I have seen different images from the various sites, but they dont seem to show the wiring connections.

Hire a subcontractor.

Just a minor job like an earth wire run from the motor frame, in the present case you will have to connect the ECC to a terminal at the bottom of surge arrester and will go up to earth pit.

I have seen separate earths for lightning arrestor,transformer neutral and transformer frame. Verify from your utility.

Phone the Surge Arrester manufactuer

Dear Toba,

Viewing your previous posts including thing one I think our Job Descriptions are alike. .

For Surge Arresters Earthing you would require the following:-

Earth Electrode

Earth Test Clamp

How do we know that the lifespan of a surge diverter has expired or damaged?.

I agree with mountk2 that the surge arrester should not be earthed via the transformer tank as this could create serious problems in the transformer in the case of a lightning strike. After all we are trying to protect the transformer.

The earth connection may be made to the substation earthmat as opposed to building a new earth pit.

The cabling will not , normally, be supplied with the surge arrester.

In order to assess the life remaining in the arrester an event recorder can be interposed in the line from the arrester to the earth these units are readily available.

I agree with#8 and also I would like to say :

1-You can check also the web site for companies spechialized in earthing systems.

2-In case of considering the number of events as an indication for the arrester life , please note that the surge arresters are usually provided with surge counter and which can help for the number of surges instead of using event recorder with cost pluse to the system price.

Thanks everyone! I'm really grateful, I understand better now.