208 power?

[no704]

Guy I work with asked me if we had 208 power available. As I have wired most of our shop tools I was only aware of 220 1ph. Or 220 3ph. So I told him no 208. He is looking for a UPS for our server.
Later he tells me he thinks 208 is using the two 110 legs, like you would find on a 220 line but to each other instead of the neutral.
Does this seem correct? I’m not seeing it.
Thx.

 

[Bert_]

240 3 phase is delta. 208 3 phase is wye

 

[no704]

240 3 phase is delta. 208 3 phase is wye

That’s what i told him when he asked.

 

[The Cobbler]

a building I was involved in many years ago each leg was 120 volt & combined was 208 .

 

[wyliesdiesels]

Guy I work with asked me if we had 208 power available. As I have wired most of our shop tools I was only aware of 220 1ph. Or 220 3ph. So I told him no 208. He is looking for a UPS for our server.

there is no 220v in the US. its either 208v, 240v or 480v.... when spec'ing equipment its important to use the correct voltage rating...

Later he tells me he thinks 208 is using the two 110 legs, like you would find on a 220 line but to each other instead of the neutral.
Does this seem correct? I’m not seeing it.
Thx.

not quite

208v is derived from a 208Y/120 3 phase service. you can have 208v single phase, where you only have 2 ungrounded conductors and a neutral from a 208Y/120 3 phase connected transformer....

 

[walta]

I would not be surprised if your building had 208 volt service if is large was built after 1980.

Post a photo of the panel with the 120 volt breaks.

If the panel has a mix of single phase and 3 phase breakers the service will be 208 or 240 high leg.

A high leg panel will have 1 unusable slot for every 2 120 breaker.

High-leg delta - Wikipedia

en.wikipedia.org

Walta

 

[wyliesdiesels]

a building I was involved in many years ago each leg was 120 volt & combined was 208 .

thats a 208Y/120v service. 120v ungrounded leg to grounded leg(neutral), 208v ungrounded leg to ungrounded leg.

 

[sparky 1971]

Take the cover off the panel and check the voltage phase to phase using a digital multi meter. It will either be 208ish or 240ish.

 

[dave*99]

We had 208Y/120v service in our building at work. Sometimes specialized equipment requiring 240 single phase was ordered (by some uninformed folks.) The company electricians would have a fit. They would end up installing a step up transformer to go from 208 to 240.

 

[no704]

Hmm, now I question myself. It’s been a couple years since I wired any thing here. Panels can take a single, double or triple breaker. For 120, 240 or 240 3 ph as I recall. I’ll get a pic tomorrow.

 

[Bert_]

Do you have 1 pole breakers that skip every 3rd space? A separate panel that only has 1 phase in it? These are good signs that you have a 240v delta service.

If you can get 120v from any of the 3 phases then you have 208Y

 

[sparky 1971]

Hmm, now I question myself. It’s been a couple years since I wired any thing here. Panels can take a single, double or triple breaker. For 120, 240 or 240 3 ph as I recall. I’ll get a pic tomorrow.

A picture might verify that you have three phase power, but that's it. Unless there is a picture of a meter testing line to line, nobody will be able to tell you what the voltage is. It's either 240 or 208.

 

[no704]

 

[Bert_]

It's definitely 208v. You have 3 phases in the panel and single pole breakers (120v loads) on all 3 phases.

 

[no704]

Thanks everyone!

 

[walta]

I agree 208 Volts

You may want to check the tags on the equipment connected to the 2 and 3 pole breakers and make sure they are rated to operate on 208.





Walta

 

[no704]

I agree 208 Volts

You may want to check the tags on the equipment connected to the 2 and 3 pole breakers and make sure they are rated to operate on 208.



Been running a couple years. I’m sure I checked when I wired them.

Just made more work for me! Thanks.

Most of it is 3 ph.

Walta

 

[walta]

Yes, it has been working for some time but it seems the person installing the equipment was confused about what voltage was being supplied to the equipment and without that knowledge he might not have noticed a tag that says 240 volts as apposed that says 208\240.

Yes, the 3 phase equipment needs to be checked also because it can be labeled 240 volt only.

Sorry about the extra work.

Walta

 

[Norcal]

I agree 208 Volts

You may want to check the tags on the equipment connected to the 2 and 3 pole breakers and make sure they are rated to operate on 208.





Walta

That is a non issue, the 1 & 2 pole breakers normally are rated 120/240V, and any phase is 120V to N, so it does not exceed the lower voltage. It is only a issue with 120/240V 3Ø when the high leg & another phase is used for 240V single phase loads, a 240V rated breaker is required, they are uncommon & expensive,

 

[fitter30]

Need either higher or lower voltage a buck boost transformer can give you what you want.

 

[no704]

Thanks all. I will double check voltages got the equipment.