480 to 208

[rene13hebert]

I had to replace a 480 to 208 transformer. The original was rated at 120 amp and my temp fix is 75 kva. The line breaker is 60 amp 480 and I need at least 160 amps to replace it. What should I get as far as kva? Thanks.

 

[Pete999]

Think you need to be a bit more specific mate.

 

[rene13hebert]

The problem is I'm working on a boat repair yard. Some vessels have 3p 208 for their power supply. And that usually runs between 90 +100 amps using an 100a fuse on the load side. The dock itself runs at +20 amps.
The power for the dock is 408 and the line breaker is 60a.

 

[Darkwood]

I had to replace a 480 to 208 transformer. The original was rated at 120 amp and my temp fix is 75 kva. The line breaker is 60 amp 480 and I need at least 160 amps to replace it. What should I get as far as kva? Thanks.

Welcome to the forum.

We need to know a lot more detail before we can even consider answering this, your profile is empty so we don't even know your origin which with the forum been based around the UK regulations is info we require so we can ensure the voltage ratings in discussion are correct.

When selecting a TX and its upstream fusing you first need to know the task and duty the TX performs and the expected loading and duration if you can list these and any other relevent info we may be able to help.

Can you also let us know your Electrical level as this would help us ensure our answers are tailored to your knowledge and experience.

 

[rene13hebert]

I found a GE 75kva transformer and am using it to supply power for the dock and had to use a 45kva to supply the boat separately. All this went down Friday evening as a temp patch.
I want to upgrade this system so it doesn't happen again. My lead man got fired and I've been handling the electrical work alone. I just recently became a first class electrian through a marine apprenticeship but I'm sure you can understand that I know there is still a lot to learn expecially on the fly. Thanks again.

 

[rene13hebert]

Ok. I'm a marine electrian in the U.S. completed a 5yr apprenticeship and have been in the field 3yrs focusing on marine. Had little experience on the industrial and residential side. Mostly working wiring up boats.

 

[Darkwood]

Thanks - I have relocated the thread to non UK Electrical so members are aware and can advise accordingly... your experience is fine, no need for us to simplify our posts

 

[rene13hebert]

Thank you so much. I know I'm good at 90-100 amps but wanted to compensate for a max draw without burning up another transformer blowing countless fuses or just having egg on my face. Thanks again. They're driving me nuts here saying "just switch a leg"

 

[Darkwood]

I haven't worked the marine sector before so your own experience may be good their, depending where this Tx is been installed, you may need a Marine Duty TX if its say onboard a vessel. Ill provide a few links as you need to attain whether the existing Tx was actually suitable for the task, we need to know what was the cause of the original failures, it may not be as plain as it seems - do you have loads that create excessive harmonics etc, this will all be crucial to choosing the right kit.

I would IMHO pick a manufacturer of TX's and deal direct with their technical department - often they will ask you questions and source info that was not on the table on a forum.

Here's a link of various Tx and there advantages.

Also I believe the USA has new requirements regarding the efficiency of any new Tx as of Jan 1st 2016 so you need to look into that too.

Eaton's low voltage dry-type distribution transformers

 

[rene13hebert]

Thanks

 

[Pete999]

Thank you so much. I know I'm good at 90-100 amps but wanted to compensate for a max draw without burning up another transformer blowing countless fuses or just having egg on my face. Thanks again. They're driving me nuts here saying "just switch a leg"

Good luck Rene, hope you get your problem solved, I worked in the US for about 4 months,could never get my head around your systems completely, all the best.