Fan Cooled Transformer's

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necnotevenclose

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I found out a while ago that GE is producing and maybe replacing some of its transformers with fan cooled transformers. Has anyone installed these on a project? And what is everyone's comfort level on using these?

Your replies are greatly appreciated.
 
It just so happens....

WHOITRANS1.jpg


this arrived on the job just last week. If I recall it is a 500 KVA 480 - 208Y/120. It is about 5'H x 5'W x 4'D

What you see is how it ships, I am not happy at all.

There is very little space for what I have to bring in and out.

The primaries will be two sets of 600s in 3" FMC. They terminate on the bottom of the modeled case shunt trip switches.

The secondaries will be four sets of 600s in 4" FMC. The locations for XO are on the extreme left and right more or less behind a A or C phase.

Once you try to add lugs to XO the lugs get close to the other phases.

If the fans must run 24/7 to keep the transformer cool I give those pancake fans no more than a five years.

There is also an an alarm and if over temp happens...... I mean when over temp happens the shunt switches shut down the primary.

It is very nice of them to use up all the space below with fans.:rolleyes:

WHOITRANS2.jpg


I would have been a bit upset if I had conduits coming up through the slab.

Notice the classy job of running the fan wiring through unbushed holes in the frame work. :rolleyes:

This is an improvement?
 
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hardworkingstiff said:
Bob,

What brand it that?
Click to expand...

GE

Is that particle board on the sides?
Click to expand...

LMAO....no offense to you.

I was laughing because it would not surprise me if that will be the next improvement.


No it is not wood, it is sound insulation it feels like dense fiberglass.

Not sure the insulation will make up for the noise of the fans especially down the road when they get worn bushings and start to vibrate.
 
...and I bet you just love the grounding provisions :D

We just so happen to have a 400 KVA model on our project. The enclosure is little smaller than yours. Six fans?3 front, 3 rear?and only one molded-case switch?on the primary. The X0 terminal buss is a lot better situated than your model... X3 and X2 to the left of the switch while X1 and X0 are to the right.

The primary feeder is two sets of 500's in 3-1/2" EMT/FMC, entry on left side. The secondary is six sets of 400's in 3-1/2" FMC, entry on the right. We got it wired but definitely not without quite a few cuss words involved :D
 
Do the fans increase the transformer rating? The utility substations
are rated with fans. Eg a transformer rated at 20000 kva would be 22400 kva
with fans.
Was there some reason you requested the fans or did GE just "give" them to you?
 
bob said:
Do the fans increase the transformer rating?
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There is only one rating on the tag, what I think we are getting is a K rated 500 KVA transformer with a smaller footprint than one with out fans.

Was there some reason you requested the fans or did GE just "give" them to you?
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I did not see anything in the job specs that called out for a fan cooled transformer.

I am under the impression it was a 'gift' from GE.
 
iwire said:
It just so happens....

WHOITRANS1.jpg


There is also an an alarm and if over temp happens...... I mean when over temp happens the shunt switches shut down the primary.

I would have been a bit upset if I had conduits coming up through the slab.

This is an improvement?
Click to expand...

So the transformer has an alarm that shuts down the transfomer when it overheats. Does this mean you have to bring in an additional 120V or 24V connection for the alarm? Also is this an audible alarm?

Also you mention you would be a bit upset if I had conduits coming up through the slab. Does this mean there is no way to bottom feed this? Or are you saying you have conduit size limitaions?
 
First let me say I have not looked at a manual for this transformer yet and it has not been fired up.


necnotevenclose said:
So the transformer has an alarm that shuts down the transfomer when it overheats.
Click to expand...

There is an audible alarm, fans, shunt trip switches etc.

How they are set up to operate I have yet to find out.

It looks like the control power for all this is taped from the primary feeder.


Also you mention you would be a bit upset if I had conduits coming up through the slab. Does this mean there is no way to bottom feed this? Or are you saying you have conduit size limitaions?
Click to expand...


You can come into the bottom through the slab if GE provided good cut sheets or the unit was on site to measure before the slab was being poured (not likely) The only clear spot in the bottom is small so you would have to locate the conduits perfectly. Not a problem at all with good info, which GE has not been forth coming with.
 
If the transformer was not specified properly, a savvy (or sneaky) transformer supplier will take advantage of the situation by providing a lower KVA transformer, sticking fans on it, and getting anywhere from 115%, 125%, and on real large units 133% increase in power output. It is cheaper to buy less KVA, and put on fans, then to buy full KVA without fans. The way metal prices have skyrocketed that maybe what occured. If there were space limitations in the spec, this may be how they were able to shrink it down in size, but still get the needed KVA.

At 480V HV side, most likely the fan power is tapped from there as mentioned. Since you can continue to operate without the fans, especially at a lower KVA, I doubt the initial alarm will cause a shutdown. It may also have a high/high alarm setting that will need to be wired to trip the primary breaker. Check the warranty to see what happens when the fans crap out.
 
The smaller ones are a little more user freindly for field wiring. GE does publish cable entrance specs. I found it buried in their site. Do the XFMR's come with anything?? Of course by then it's a little late as you say Bob.

I haven't run into one this big. The smaller ones are great for bottom entry if you know where to lay out the conduits.

Most guys I've talked to say they take longer to set.

I did some digging on XFMR's regarding cable entry. The standard ones all have recomendations not to block ventilating openings. Strict adherence to that would prohibit entrance from the bottom. Not that I'm trying to change the world or anything. We've been doing that forever and I've never heard of a failure because of it.
 
iwire-Thanks for the pics for some reason my computer did not bring up those images. I can see how GE decided that ease of installation need not be a part of Transformore.

Sceepe-Thanks for the link. It's too bad that they did not provide close up photos like iwire sent.

Another question I have is that if you are building based off of engineered documents and the engineer does not mention these types of transformers is the engineer than RFI'd to see if these will be acceptable to use?

I don't see how GE can just provide surprises like this to a project. Don't they understand that getting these approved from the engineer and then figuring out how to properly install these will take more time and increase labor! Is GE providing any funding to take care of this?
 
necnotevenclose said:
Another question I have is that if you are building based off of engineered documents and the engineer does not mention these types of transformers is the engineer than RFI'd to see if these will be acceptable to use?
Click to expand...

I will be back at the job tomorrow and will look over the paper work more carefully.

That said...yes it is an engineered job with a large set of specifications.

Our vendor submitted a proposal based on the job specs, we in turn provided submittals to both the engineer and the customer, the submittals where approved and we released the equipment.

I do not believe the specs say if fan cooled units where or where not acceptable. I do not believe the submittals mentioned these would be fan cooled and overtemp protected.

I think GEs positions is "You asked for a 500 KVA transformer of a certain class and that is what you got"

We will be wiring it up this week and continuing with the job.
 
I've already added a "no-fan cooled transfromers" clause in my specs after seeing someone else mention them about 2 months ago (or was it you that mentioned them a while back, Bob?)

Steve
 
steve66 said:
I've already added a "no-fan cooled transformers" clause in my specs after seeing someone else mention them about 2 months ago (or was it you that mentioned them a while back, Bob?)

Steve
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No but I recall someone bringing them up I just can not remember who.

As far as adding the no fan cooled clause good for you and hopefully other engineers will do so as well.

Right now transformers in this size range where essentially maintenance free, sized properly they run forever.

Now we add a bunch of parts that are likely to break and shutdown the power.

I don't see that as moving in a forward direction.
 
Here are a couple 1500 KVA units with 12 fans each that our company installed recently.

One was 12470 / 480 and the other was 4160 / 480
1500kva.JPG








1500kvaopen.JPG



Sorry about the picture quality.

I must say I don't have any experience with smaller ones so I can't give an opinion there, but looking at Iwires pictures I can see I would not be happy either.

Roger
 
iwire said:
It just so happens....


The primaries will be two sets of 600s in 3" FMC. They terminate on the bottom of the modeled case shunt trip switches.

This is an improvement?
Click to expand...

Bob
I just noticed something.
Are the primary conductors coming off one C/B at the source??
If so somethings wrong here!! Parallel conductors cannot terminate to two different places on the load end.
Or so I thought??? what's up with that?

I've seen a few HV dry types and fans were all standard for the most part.
 
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