Surge arrester for a small padmount transfromer

[FaradayFF]

Hi All,
Are surge arresters generally only provided on the high voltage side of a transformer? Are there any scenarios where surge arrestors should also be provided on the low voltage side of transformer? This would be for 3 MVA unit with underground feed into the can with no above ground exposed cabling.
Thanks,
EE

 

[electrofelon]

3MVA is small?

 

[MD Automation]

3MVA is small?

Ha ha! It all depends on your yardstick

fwiw - in all the years of working at my small company, my transformer yardstick topped out around 75kVA.

 

[electrofelon]

Ha ha! It all depends on your yardstick

fwiw - in all the years of working at my small company, my transformer yardstick topped out around 75kVA.

Yeah, if i saw like a 10kva padmount id be like awww thats the cutest little thing ive ever seen. I guess some people would say the same thing about a 3 MVA....fisher price -my first transformer.

 

[JoeStillman]

Sounds like a padmount instead of a substation transformer. What is the secondary voltage?

For padmounts with LV side under 600V, I would not have LA's on the secondary. But I would call for a surge suppressor wherever the secondary enters a building or goes up a pole.

 

[D. Castor]

Hi All,
Are surge arresters generally only provided on the high voltage side of a transformer? Are there any scenarios where surge arrestors should also be provided on the low voltage side of transformer? This would be for 3 MVA unit with underground feed into the can with no above ground exposed cabling.
Thanks,
EE

I'd put put the low side surge protection at the incoming switchboard. And the high voltage arresters at the transformer if possible.