In Need Of 3 Phase Step Down Transformer
 

We are looking for a 3 Phase Step Down Transformer. We have a 3 Phase 100kw generator and need the step down transformer to bring the power down to single phase for use in a church camp facility.

If anyone knows of any good deals out there please let me know. (preferably in the Texas area... I don't know how big or heavy these things are and how hard they would be to ship)

Thanks,...

Re: In Need Of 3 Phase Step Down Transformer
 

Veeerrrrrryyyy Heeeeaaaaaaavvvvvyyy for thier size!
We had one for our Church in Burnaby for a AC Unit that we bought.
They tend to be noisy too!

I pray you locate one local at a good price!

Re: In Need Of 3 Phase Step Down Transformer
 

Much appreciated brother...

Re: In Need Of 3 Phase Step Down Transformer
 

Thought you were talking about a new 3 step salvation plan...LOL

Re: In Need Of 3 Phase Step Down Transformer
 

:spit

Re: In Need Of 3 Phase Step Down Transformer
 

Here ya go:

http://www.avtron.com/images/jpgs/k922.jpg

Re: In Need Of 3 Phase Step Down Transformer
 

HA... Nope... :)

Re: In Need Of 3 Phase Step Down Transformer
 

We were looking for something just a leeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeetle smaller. :)

Re: In Need Of 3 Phase Step Down Transformer
 

OH BOY! an electrical issue!

A couple of things:
Austin International
http://www.electricalconnector.com/
nice folks --easy to deal with, tell them what you want
primary side 480V primary (delta or wye) to 208/120 (wye) secondary.
primary will have either 3 wire connection or 4 (nuetral) but secondary MUST BE 4 wire.
You will be looking for a transformer rating that is at least your generator rating x 1.25 (if generator is in Kw), this is because you will want to match the KVA capability of the transformer with the KVA capability of the GENERATOR.

A slightly larger xfmr will not hurt you at all.
A dry type transformer WILL GET HOT and must be under a shed as a minimum. In the smaller KVA sizes (200 and below) most transformers will be dry type.

This is a VERY COMMON size transformer (480V (3wire) to 208/120V (4 wire secondary), since almost every commerical building has the need for the same thing.

REMEMBER!!!! GENERATORS ARE LIMITED BY THEIR HIGHEST PHASE LOADING...in otherwords...their rating is SET by the SUM of three things (PHASES) being utilized, THE TOTAL CAPACITY is only there when each of the three phases are fully utilized.

SO TELL YOUR CAMPING BUDDIES....be very careful in how they load the branch circuits on the distribution panel that will be on the secondary of the transformer

----IS THIS FUN or WHAT!!!! I haven't enjoyed myself this much on AFF since talking with Adino about water baptism's equivalence in destroying a taskmaster with the Red Sea's destruction of a former taskmaster!

Example:
Your Generator is 60KW 3p, 4w with a 480V output.
Make sure your transformer is at least 75 KVA and has a secondary that is
4 wire 208/120 (once you have the 'double' secondary voltage you have a four wire connection because it is the LINE to NUETRAL voltages that provide the 120V.

Re: In Need Of 3 Phase Step Down Transformer
 

Re: In Need Of 3 Phase Step Down Transformer
 

Finally... I'm on it... I am going to pick it up in my mini van as soon as I get off work.


By the way.... HILARIOUS....:ursofunny:ursofunny:ursofunny:ursofu nny

Re: In Need Of 3 Phase Step Down Transformer
 

:thumbsup

Re: In Need Of 3 Phase Step Down Transformer
 

D4T,
Since your power center will be a distribution panel on the SECONDARY of a transformer, I strongly suggest that you and your CAMPER TECH STAFF, construct a driven grounding electrode system to provide the 'earthing' of your transformer's secondary NUETRAL.

Your electrical distribution system NEEDS to tied to ground to stablize the phase voltages and to insure a real return path to source exists at the time of ANY (including the FIRST) phase to ground fault.

Re: In Need Of 3 Phase Step Down Transformer
 

TB, who taught you English? Commander Scot of the USS Enterprise? :lol

Re: In Need Of 3 Phase Step Down Transformer
 

D4T, glad it all is working out for you!

Re: In Need Of 3 Phase Step Down Transformer
 

So long as he doesn't mention matter & antimatter streams!:thumbsup

Re: In Need Of 3 Phase Step Down Transformer
 

One final thing (like I can really ever just have one last electrical thought!)....

You can meet your need by deploying three single phase transformers. Your world (temporary electrical distribution system) is going to be limited by the single phase capacity of the generator so three (3) single phase transformers would be used to match (or exceed) the rating of the generator.

It turns out that you can ADD KVA ratings to get to the total.

Example
3-20 Kva single phase transformer would provide 60 KVA when connected as a three phase connected as an assembly in a delta or in a wye (3w or 4w) configuration.

The only advantage MIGHT BE the weight and volume of each part involved in the transport and temporary installation. THE CAUTION would be in making sure that you follow POLARITY indications. IF YOU END up with three single phase units PLEASE CALL ME or send me pictures and I will go over how to make the connections if you do not have an electrical resource that is familiar with polyphase installations.

Re: In Need Of 3 Phase Step Down Transformer
 

Will do bro. We want this to be a long term system and a driven ground is a small price to pay to ensure a stable voltage.

Re: In Need Of 3 Phase Step Down Transformer
 

I certainly will. Thanks a million...

Re: In Need Of 3 Phase Step Down Transformer
 

I would suggest 2 or even 3 (rods)....and if it may be there for years....3/4" copper clad rather than 5/8 galvanized (supply houses almost always carry both).

You will need the basic clamps and grounding electrode CONDUCTOR...to interconnect the grounding system (without splicing).

Depending on the size of your secondary service conductors.....will set your grounding electrode conductor....

See table 250-66 in NEC (2008) --table no. may be different if you are referencing an earlier NEC version.

The softer the soil, the poorer the ground. A rod that takes a bit of a work-out to drive is best (soil is tight but has moisture).

The reasons I suggest multiple rods is because for your PRIMARY grounding system we want to achieve the lowest grounding resistance within a reasonable effort. Rods should always be installed with a MINIMUM SPACING of six feet.

......

ON THE OUTSIDE chance this installation involves the pouring of a concrete pad, a UFER Ground system can be used in lieu of the driven electrodes. This is an excellent approach if the soil is rocky or very dry (moisture is key to ground conductivity)

Re: In Need Of 3 Phase Step Down Transformer
 

All this electrical talk makes my head spin.

Now setting up an IP network.... now THAT is something I can handle.

Re: In Need Of 3 Phase Step Down Transformer
 

:ursofunny

I catch on to some but some of it is above my head too. I have forwarded all of tbpew's info to the electrical gurus that be.

Hopefully they will be up to the task of full understanding. :)

Thanks again tbp.... much appreciated.

Re: In Need Of 3 Phase Step Down Transformer
 

D4T, that kind of electrical equipment will easily fry you if you make a mistake, do you have someone qualified to do it?

Re: In Need Of 3 Phase Step Down Transformer
 

Yes sir... one of the brethren is a licensed electrician who does this kind of thing for a living.

he is the one I forwarded all of the info to.

I am just trying to find a step down transformer (we found a used one for $1700 but still looking in case we can find a better deal). Don't let me level of understanding scare you. :)

They will be keeping me far from it when the installation goes on.

Re: In Need Of 3 Phase Step Down Transformer
 

that price sounds more like what a new one would cost.
If you tell me:

KVA (or Kw) of generator
Output voltage of Generator
Will this installation be out of the weather

I can get you a quote from Austin International (used equipment but has some initial warranty).

If you are not opposed to used units, I may be able to locate one up here that could only cost you $250.00 plus shipping (another $250.00??).

Let me know if this seems worthwhile...but until Austin has quoted you...DO NOT BUY from somebody else!

Re: In Need Of 3 Phase Step Down Transformer
 

Good grief....I thought this was another 1 Step vs 3 Step discussion

Re: In Need Of 3 Phase Step Down Transformer
 

I am attempting to find out that information now.

I do know that it is a 100kw generator and that the installation will be out of the weather. We feel that we need to enclose it to help deter theft if for no other reason.

Re: In Need Of 3 Phase Step Down Transformer
 

Actually portions of the thread have been... didn't you read tbpews posts on using multiple 1 phase transformers?

:)

Re: In Need Of 3 Phase Step Down Transformer
 

Good to hear!
I think tbpew is an Electrician!

Re: In Need Of 3 Phase Step Down Transformer
 

Okay... I have the info.

It is a 100kw generator
480v max (150v per leg)
It can be inside or outside. The plan is for inside because of theft issues with the facility being empty most months.

Re: In Need Of 3 Phase Step Down Transformer
 

Got it.

I will make contact with my rep at Austin and see how their quote matches whatever other options you come up with.

The phase current rating you provided would match a 125KVA generator rating which would be fully consistent with a 100kw rating.

I will go ahead and do some basic sizing stuff for your guys to reflect upon, consider or discard.

regards,
tbpew

Re: In Need Of 3 Phase Step Down Transformer
 

Sounds great