OT........110VAC 3 Phase......??

Hello all,
To start with I did not do this.....I am the lucky one to figure it out..... With that being said we have an Ozone generation machine that was built in South America. It was orderd to run on 110 VAC 3 Phase. Is their such a thing? Right now it is wired to three different 110 panel breakers with a panel neutral (it is an awful hack job). It works but I do not think that it the way is should be wired......any suggestion.... as always feel free to ask anything so I can help find a solution.
Micheal

Are there any 3 phase motors on the unit? If so what voltage are the motors rated at. Also are there any other 3 phase loads on the generator?

You should be able to get a 3 phase transformer assuming you have 3 phase service. Just get the correct step-down ratio and size to suit. I believe Jefferson makes one.

are you sure it isn't 3 pole 208-120 ?

stasis said:

are you sure it isn't 3 pole 208-120 ?

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That's why I asked about the motors.

If the three different breakers are all immediately adjacent to each other then the phase to phase voltage will be 208 or 240VAC, depending on the service - despite the fact that single pole breakers were used.

I put in a 400A 240V3PH service for a machine shop. I was just tapping the old service that was there. I remember I had 240V phase to phase, and 120V on at least 2 legs. I'm not sure what was on the third leg. I'm not that familiar with transformers, but be careful you don't tap a 'high' leg for 120V equipment. I believe the transformer supplying the buildings might have been called an 'Open Delta'. Not positive though.

well, transformers work on a ratio basis, and you could get 3phase at 120V (nominal), but it isn't common.

to the OP...can you give more specfifics?

if you are using three separate panels to feed this machine's service, then there are several codes being broken...if you are feeding the machine's service with separate breakers within the same panel, this is also against code.

Alaric said:

If the three different breakers are all immediately adjacent to each other then the phase to phase voltage will be 208 or 240VAC, depending on the service - despite the fact that single pole breakers were used.

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Right, and if this is a single phase panel he wired it too and the breakers are all adjacent there will be 0V across two of the legs.

Both of these circumstances would be quite bad, as in let the smoke out of or start a fire bad.

What we really need to know is if there are any actual 3 phase loads on the ozone generator. A power schematic of the machine would be nice if available.

yam785 said:

I put in a 400A 240V3PH service for a machine shop. I was just tapping the old service that was there. I remember I had 240V phase to phase, and 120V on at least 2 legs. I'm not sure what was on the third leg. I'm not that familiar with transformers, but be careful you don't tap a 'high' leg for 120V equipment. I believe the transformer supplying the buildings might have been called an 'Open Delta'. Not positive though.

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120V in the US is supplied by two methods. The first is 208/120 where the transformer has a WYE secondary with the center tap of the WYE making the neutral. This gives you 208V between each phase and 120V from phase to neutral. You most often find this in commercial settings.

The second is a transformer with a 240V delta secondary where just one winding of the delta has a center tap. This tap is grounded to form the neutral. Each leg on either side of the tap delivers 120V with respect to the neutral, but all three legs are 240V with respect to each other. Nothing should ever be connected between the third leg and the neutral. Most residential power is of this type and the thrid leg is almost never connected to the customer unless the customer is an industraial user.

There is a 3 phase 120 VAC system. It is NOT a common utility supply. The two low voltage descriptions of which Alaric gave are correct on these except there is also 120/240 single phase. This is what is supplied to residential services. I have only seen a 3 phase 120 volt motor one time in 25 years and it was offshore related. The system reads just like any other multi-phase system. Between any two phases you get 120 which is the rated voltage. Just like on a three phase 208 you read 208 between phases, on a 240 you read 240 and on a 480 you read 480 between phases.There is no neutral so you don't get a line to common reading on the 120 three phase sytem.

What you are doing is wrong, a code violation and unsafe. I am not even sure how it is working properly. Have you amped out each phase to insure you are within the rated FLA? What you need is the proper transformer to step down from 480 or 240 three phase to 120 three phase. This is a very unique transformer and will take some looking to find but you should be able to do it. Good luck.

g.robert said:

There is a 3 phase 120 VAC system. It is NOT a common utility supply. The two low voltage descriptions of which Alaric gave are correct on these except there is also 120/240 single phase. This is what is supplied to residential services. I have only seen a 3 phase 120 volt motor one time in 25 years and it was offshore related. The system reads just like any other multi-phase system. Between any two phases you get 120 which is the rated voltage. Just like on a three phase 208 you read 208 between phases, on a 240 you read 240 and on a 480 you read 480 between phases.There is no neutral so you don't get a line to common reading on the 120 three phase sytem.

What you are doing is wrong, a code violation and unsafe. I am not even sure how it is working properly. Have you amped out each phase to insure you are within the rated FLA? What you need is the proper transformer to step down from 480 or 240 three phase to 120 three phase. This is a very unique transformer and will take some looking to find but you should be able to do it. Good luck.

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I have never seen a 110V three phase motor but that certainly isn't to say that they don't exist. I have no idea what the electrical distribution is in South Africa.

I am suspecting that something got lost in the translation and that 110V 3 phase actually means a 208V L-L wye supply with a neutral. The fact that it is "working" and nothing has burnt up makes me suspect that it is being supplied from a three phase 208V panel and that three single pole breakers are being used instead of a three pole breaker. That is against code but can be easily rectified by installing a properly sized 3 pole breaker.

However, those are big assumptions and might be totally wrong! Until you have this straightened out you need to shut it off. Some motor nameplate data and a power schematic would help alot.

XtremeIN, BTW there are manufacturers in NA that will sell you an ozone system and save you some headache. But I think you already knew that, you are not the first to get stuck with someone eleses mess.

Per NEC a breaker (or breakers) feeding a multiwire circuit shall interrupt all current carrying conductors simultaneously (EXCEPT the neutral). The neutral CAN be broken by the breaker and is done where you have a GFCI single phase breaker but that is another issue irrelevant to this I think.

In a 3 phase panel such as those we have at work a multiwire circuit is derived from any breaker the guy found that would give him what he wanted ie 208 single phase or 208 three phase. I fight this daily. EXTREMELY DANGEROUS circuit
not only that it is quite frustrating in unlabled panels to do hunt and peck just to get all 3 wires in a box (IF the boob put em in a box) dead.
ANYWAY
Have all 3 breakers adjacent. Now it can be argued that they should be a single unit ie 3 pole. What is commonly done especially in the past is to tie them together with a tie bar. Supposedly this works and is supposedly legal, but I really prefer the single 3 pole breaker.

The only place I have seen 120 VAC 3 phase was in the Navy where it was derived via transformers from 450 3 phase. At least on that boat all electrical was ungrounded and we did not have a neutral in the distribution system. I do not remember ever seeing a 3 phase 120 V motor either in the Navy or in the civilian world.

Is this possibly a marine application? Now I do not know if commercial marine uses 120 3 phase but if a ship were ex Navy it may very well be the case.

Basically all three phase transformers consist of 3 single phase transformers connected together. It is therefore possible to get 3 single phase transformers with 120 V secondary and whatever your primary voltage is and connect them. Let me caution you that unless you really know what you are doing with this it is very easy to make a mistake and burn out one of your transformers or your load or burn you.

I think you should disconnect this before it burns up.
I think you need to read the manual on this equipment.
IF all else fails call the factory.

The other thing I would do is check the nameplate if there is one
AND see if the input power connections are labeled. Common markings in USA are:
IF L1 L2 and L3 AND each is fused in unit (or a breaker) it is more than likely 3 phase.
IF it is only L1 and L2 and only two fuses (or 2 pole breaker) it is more than likely single phase. There may be a third connection and that will more than likely be for the neutral in this case.

Check phase to phase voltage A to B A to C and B to C
AND check phase A and B and C to neutral voltage. Once we know these readings we can help further.

Dan Bentler

Thanks for all the information so far. Alot of it is over my head, but atleast I am learning something.... I will get a few pictures and see if they help. There is no wiring diagram. I know it is not being run off 208 3 phase because it was wired to 208 3 phase when it was first brought it in and it burned up several components that were rated 110. The only Transformer within the control box ia a 110v to 24v step down. From what I can tell the motors are 3 phase, they are a common Grundfos pump/motor combo and rated for 3 x 200-230/346-400. The three 110 lines running to the machine are from three different breakers within the same panel; this same panel is used to control outlets and lighting with in the office part of the building. I know it is not up to code that is why I am trying to correct it. To figure out if it is 110 3 phase or 208-120 or whatever where should I read voltage and what should I bee looking for......?
Thanks,
Micheal

It will say right on the panel either 120/208V or 120V/240V. Either one of these is acceptable for office lights plugs etc..

If it says 120/208 it is a 3 phase panel, if 120/240 it is single phase. If you pull the cover off of the panel you will either see either 2 or 3 conductors feeding it (along with a neutral).

Take a picture of the main disconnect or main breaker or whatever it has and post it along with the info Dan asked for.