utility transformers

[mickeyrench]

I have little expierance in this area but on utility trans where is the protection for the transformer located ? We have 6 transformers for one service and I don't see any protection anywhere , above or below. Thanks for any help here.

 

[iwire]

I have little experience in this area but on utility trans where is the protection for the transformer located ? We have 6 transformers for one service and I don't see any protection anywhere , above or below. Thanks for any help here.

The short answer is there is none.

There will be fused cutouts or a breaker somewhere but they are not sized to protect the transformers they will be sized to protect the rest of the grid if the transformer faults.

 

[mivey]

The short answer is there is none.

There will be fused cutouts or a breaker somewhere but they are not sized to protect the transformers they will be sized to protect the rest of the grid if the transformer faults.

They may be completely self protected (CSP) units. see here:
http://www.cooperpower.com/Library/pdf/20110.pdf

Also, some utilities do size the fuse to protect the transformer. Not sure about N.J.

 

[iwire]

I have not seen an indicator light on any new tank for a long time, once in a while I will see an old unit with the light. But I should never speak about power companies in absolutes, they are all different.

 

[Power Tech]

I have little expierance in this area but on utility trans where is the protection for the transformer located ? We have 6 transformers for one service and I don't see any protection anywhere , above or below. Thanks for any help here.

Is this overhead or underground?

Underground transformers (not all) have internal fusing.

 

[mickeyrench]

These trans are on the ground and lockup behind a fence. Thanks again.

 

[ohmhead]

These trans are on the ground and lockup behind a fence. Thanks again.

Well do they look like this http://i611.photobucket.com/albums/tt195/stringking/IMG_0636.jpg


If they do look the same the HV fuses are inside the left side or the primary HV side they are snap in oil type pulled out with a hot stick.

There for the power companys protection primary side one for A PHASE one for B PHASE one for C PHASE .

They pull them out but some times you got to be carefull after a outage the oil gets real hot due to the pressure inside this can be a issue like hot oil shooting out on you but that said they have protection inside .

What part of Edison ?

 

[mickeyrench]

No not like them at all, they are a round oil filled type.

 

[ohmhead]

No not like them at all, they are a round oil filled type.

Well then if there like the tank looking ones in the other post the fuse and jack is one fuse above it attached to the pole or mounted remote from the transformer.

We call them pig poles

 

[mickeyrench]

I missed the no# 3 post . they are close to the ones there except the others have fins going verticly , close enough. Thanks

 

[ohmhead]

I missed the no# 3 post . they are close to the ones there except the others have fins going verticly , close enough. Thanks

Well ya they all are oiled filled types the fins are for cooling of the oil .

I was born in Edison NJ many years ago glad to help .

 

[iwire]

Again, don't assume anything, there is no requirement that forces the power company to 'protect' the transformer in the traditional sense like we have to under the NEC.

As Mivey point out some power companies do, but not all.

 

[mickeyrench]

small world , thanks again for your help.

 

[ohmhead]

Again, don't assume anything, there is no requirement that forces the power company to 'protect' the transformer in the traditional sense like we have to under the NEC.

As Mivey point out some power companies do, but not all.

Well its funny you said that iwire the transformer thats feeding my house which is in my yard on a pole the fuse jack is 2 miles down the road .

The bad part is iam the only one on this line & transformer so guess what happens when power gos out . Iam running a 17.5 genset

 

[mivey]

We call them pig poles

The pole-mounted transformers are called pole pigs.

the fuse jack is 2 miles down the road .

Then that is less about the transformer and more about keeping your line from interfering with the main line. That would be a tap line fuse.

The bad part is iam the only one on this line & transformer so guess what happens when power gos out . Iam running a 17.5 genset

And I'm sure you are one of the first ones they try to get back on when the power goes out. :grin:

 

[zog]

I have little expierance in this area but on utility trans where is the protection for the transformer located ? We have 6 transformers for one service and I don't see any protection anywhere , above or below. Thanks for any help here.

Without a one line of your system the only thing we can do is guess. Good chance some of the protection is part of your main breaker scheme, the differential relays. Can you post a picture of your yard?

 

[mickeyrench]

they are locked up behind closed walls and doors . i got in there once and seen the six transformers and then got a blue print and found out they were 500kva's. Imshould be able to get the one line blue print but it is old.

 

[ohmhead]

Well Mivey during heavy tropical storms down here my power is out for 14 days but during a hurricane its when they get a chance to stop by.


I have a home made solar array and generator back up but i still like to have my florida power companys line hot you feel better when fuel gets hard to get during a strorm .

Take care

 

[zog]

they are locked up behind closed walls and doors . i got in there once and seen the six transformers and then got a blue print and found out they were 500kva's. Imshould be able to get the one line blue print but it is old.

If they are inside your facility there is a very good chance they are protected by a fused load break switch. But, again, all speculation until we see one line.