3 Phase 208 to Single Phase 208

[GTUnit]

We have panels in the shop that need to be powered by single phase 220V for testing purposes before they go out the door.
Panels include AC electronics such as 24VDC Sola DIN power supplies and 12V Meanwell high current Switching power supplies.

Is it safe to use 2 phases of the shop 3PH 208V power to supply this single phase panel with 208V ?

Thank You

 

[rupej]

Yeah, I do it all the time. Voltage is voltage.

 

[dogleg43]

We have panels in the shop that need to be powered by single phase 220V for testing purposes before they go out the door.
Panels include AC electronics such as 24VDC Sola DIN power supplies and 12V Meanwell high current Switching power supplies.

Is it safe to use 2 phases of the shop 3PH 208V power to supply this single phase panel with 208V ?

Thank You

As Michael Keaton's charactor said in Mr. Mom: 220 221, whatever it takes.

Sir, with all due respect, if you are asking this question please hire a qualified electrical contractor to do the work.

This seems to be another example of a system integrator or controls engineer stepping outside their comfort zone.

 

[GTUnit]

Voltage is not voltage when it comes to switching electronics and many "qualified electricians" dont know anything.

 

[dogleg43]

Voltage is not voltage when it comes to switching electronics and many "qualified electricians" dont know anything.

Then they aren't really qualifed then are they?

 

[Cow]

We have panels in the shop that need to be powered by single phase 220V for testing purposes before they go out the door.
Panels include AC electronics such as 24VDC Sola DIN power supplies and 12V Meanwell high current Switching power supplies.

Is it safe to use 2 phases of the shop 3PH 208V power to supply this single phase panel with 208V ?

Thank You

220V is not a standard voltage.

208v and 240v are however.

I would not feed a 240v power supply with single phase 208v unless the directions or the manufacturer gave their blessing first.

 

[rupej]

Voltage is not voltage when it comes to switching electronics and many "qualified electricians" dont know anything.

GT, I hope you didn't take my post as insulting as that was not intended. I just wanted to assure you that you will have no problems. Typically, voltages are grouped in "ranges" that are pretty much all compatible. In your case, ~200 - 240VAC is all interchangable.

 

[g.mccormick]

Make sure that the acceptable range for your devices will allow down to 208VAC. Some devices may want closer to 240V.

 

[GTUnit]

I did not. Thank you for the courteous response. I appreciate it.

My concern is with the fact that with a typical Single phase feed the neutral is bonded to ground at the transformer so the neutral potential, for practical purposes, is at Zero.

When using 2 phases of 208, when we connect one phase to a single phase load hot, and another phase to single phase neutral, the neutral is at a 120V potential.

The switching electronics are rated at a Voltage range of 100V-240V input but Im worried about the neutral being "hot".
Makes no difference for transformers and motors but switching electronics are a different animal.

Ive hooked power supplies this way before and they worked.
I dont remember if i hooked the ground up or not.

GT, I hope you didn't take my post as insulting as that was not intended. I just wanted to assure you that you will have no problems. Typically, voltages are grouped in "ranges" that are pretty much all compatible. In your case, ~200 - 240VAC is all interchangable.

 

[GTUnit]

No but I'm sure you know what I mean because you have experienced it too.

Then they aren't really qualifed then are they?

 

[jraef]

I don't know of a single modern Switch Mode Power Supply on the market that is going to give a rat's patootie about being fed 208V instead of 220, 230, 240 etc. Most of them are now able to accept anything from around 180V to 270VAC input and still give you 24VDC output. Others are available that will even go 85-270VAC input by flipping a switch to get the lower range, for example so you can give it 120V nominal. most of the Sola PSUs are this type, I can't imagine Meanwell* can survive in the market if theirs didn't as well.

RTFM...

* Meanwell...one of the great name blunders ever by the way.
"It failed early, but they did mean well..."

 

[rupej]

Should be fine, just make 100% sure that no point in the panel is tying one of the phases to ground as if it were a neutral.


Switch mode power supplies won't mind one phase not being grounded.

 

[keithkyll]

i don't know of a single modern switch mode power supply on the market that is going to give a rat's patootie about being fed 208v instead of 220, 230, 240 etc. Most of them are now able to accept anything from around 180v to 270vac input and still give you 24vdc output. Others are available that will even go 85-270vac input by flipping a switch to get the lower range, for example so you can give it 120v nominal. Most of the sola psus are this type, i can't imagine meanwell* can survive in the market if theirs didn't as well.

Rtfm...

* meanwell...one of the great name blunders ever by the way.
"it failed early, but they did mean well..."

+1

 

[BryanG]

If you want to play it safe then just get a double wound transformer and create your own proper Neutral by bonding one output leg to earth. A 208/208 would do but they often have tappings on the inputs or outputs so that you can get another voltage. Just pick one with a power rating you need, I would guess that it would be about $150-$200 for a 1000VA transformer. 1000VA would give you a comfortable 3.5Amps on the secondary. Something like this can be wired for a 208 Volt input and a 230V output, or you can use the tapping to get 208 out.

 

[AustralIan]

European standardised voltage, including UK, is 230V + or - 10%. so 208 is the low end of acceptable voltages in the EU. ((230-208)/230 = 9.6%)