# phase converter?



## telsa (May 22, 2015)

papaotis said:


> ok guys, been really busy lately and havent been here but i need your help. doing a small restuarant that the owner bought all new equipment over the internet. i was told that everything was 120v. so now that im looking over all the stuff i find that some of it is 208. single phase only to this building. im thinking a phase converter is going to be the answer but im not real practiced on these. the ones ive been looking at are mostly rated by hp such as for bigger motors. if i get all the numbers together can i come up with one that power three things? one is a warming table, one is the make-up air for the hood, and one is the refrigeration unit for walk-in cooler. pretty sure the owner just didnt order right, like 'click on the voltage want'


Your thinking is insane.

Phase converters are totally obsolete.

Put a cheesy VFD on every 3-phase load -- load by load.

BTW, I can't believe that an electric restaurant can operate off of a 208Y120 single-phase Service.

That's not enough for a coffee shop.


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## frenchelectrican (Mar 15, 2007)

papaotis said:


> ok guys, been really busy lately and havent been here but i need your help. doing a small restuarant that the owner bought all new equipment over the internet. i was told that everything was 120v. so now that im looking over all the stuff i find that some of it is 208. single phase only to this building. im thinking a phase converter is going to be the answer but im not real practiced on these. the ones ive been looking at are mostly rated by hp such as for bigger motors. if i get all the numbers together can i come up with one that power three things? one is a warming table, one is the make-up air for the hood, and one is the refrigeration unit for walk-in cooler. pretty sure the owner just didnt order right, like 'click on the voltage want'


Did any equmients do run on three phase or not ? 

the warming table typically wired on single phase useally 208 or 240 volts depending on the nameplate. the only time you will see it wired on three phase if that warming table is monstor sized. 

The airmake up motor ? that is kinda pretty wide scope due the motor can be order as single phase or three phase and size will varies a bit. 

See if you can try to talk to that owner of that place to see if can swap to single phase motor. most small resturants useally use single phase motor it kinda common but med to larger places will just go with three phase motor. 

The refridge commpressor that is tossed up but if got a three phase a small VSD will do the trick but you will have to make some modifcation to the program to the VSD somehow. 
I done that twice so far. but keep in your mind about sizing the vsd you will need it be larger due you have single phase input so keep aware of that. 

try to talk to the owner to give you the specs if possible so you can able figure out some change along the way.


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## Southeast Power (Jan 18, 2009)

papaotis said:


> ok guys, been really busy lately and havent been here but i need your help. doing a small restuarant that the owner bought all new equipment over the internet. i was told that everything was 120v. so now that im looking over all the stuff i find that some of it is 208. single phase only to this building. im thinking a phase converter is going to be the answer but im not real practiced on these. the ones ive been looking at are mostly rated by hp such as for bigger motors. if i get all the numbers together can i come up with one that power three things? one is a warming table, one is the make-up air for the hood, and one is the refrigeration unit for walk-in cooler. pretty sure the owner just didnt order right, like 'click on the voltage want'


Uh, you didn't mention three phase at all and, I'm thinking like Marc, we usually see single phase 208 exhaust and warming tables. The 3 phase is usually much more money than single phase.


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## sparkiez (Aug 1, 2015)

First things first, get the owner to exchange the equipment. This is going to be your cheapest option. A phase converter isn't necessarily a good choice here.

A VFD will work for the MAU, but it may be easier just to change the motor out for a single phase motor.

The steam table, fryers, coolers, etc will not be able to be powered by a VFD.

http://www.northamericaphaseconverters.com/how-to-size-a-rotary-phase-converter/

There is a good link on sizing rotary phase converters if you insist on going down that path. I'm sure the company will offer some great support as well.


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## Big John (May 23, 2010)

I agree that explaining to the owner how this is gonna cost many thousands of dollars in specialized equipment may be enough to get them to exchange the appliances.

If for some dumb reason they refuse, then I also agree with using 200% sized VFDs wherever you can. The caveat is gonna be they can only power direct motor loads, with no downstream contractors, switches, or large non-motor components.

If you have a bunch of resistive or switched stuff that needs powering, you can still look into phase conveters. IMO, a switching solid-state unit would be your best bet, but it's gonna be expensive.


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## sparkiez (Aug 1, 2015)

Big John said:


> I agree that explaining to the owner how this is gonna cost many thousands of dollars in specialized equipment may be enough to get them to exchange the appliances.
> 
> If for some dumb reason they refuse, then I also agree with using 200% sized VFDs wherever you can. The caveat is gonna be they can only power direct motor loads, with no downstream contractors, switches, or large non-motor components.
> 
> If you have a bunch of resistive or switched stuff that needs powering, you can still look into phase conveters. IMO, a switching solid-state unit would be your best bet, but it's gonna be expensive.


I have not seen a capacitor type phase converter that can handle highly inductive loads (like a set of steam table elements) or a compressor for a steel (aka food cooler unit). That doesn't mean they don't exist though. For loads like that a rotary converter should be used.


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## A Little Short (Nov 11, 2010)

papaotis said:


> ok guys, been really busy lately and havent been here but i need your help. doing a small restuarant that the owner bought all new equipment over the internet. i was told that everything was 120v. so now that im looking over all the stuff i find that some of it is 208. single phase only to this building. im thinking a phase converter is going to be the answer but im not real practiced on these. the ones ive been looking at are mostly rated by hp such as for bigger motors. if i get all the numbers together can i come up with one that power three things? one is a warming table, one is the make-up air for the hood, and one is the refrigeration unit for walk-in cooler. pretty sure the owner just didnt order right, like 'click on the voltage want'


208V in-and-of-itself doesn't necessarily mean 3 ph. Lots of things (motors, heaters, etc.) run on single phase 208V. 
You need to look and make sure the equipment requires 3 ph, not just 208V as 208V could be single or 3 ph.

If it is indeed 3 ph, I would suggest (as has been mentioned) the owner replace the equipment with single ph.


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## Big John (May 23, 2010)

sparkiez said:


> I have not seen a capacitor type phase converter that can handle highly inductive loads (like a set of steam table elements) or a compressor for a steel (aka food cooler unit). That doesn't mean they don't exist though. For loads like that a rotary converter should be used.


 Different animal. Capacitor phase converters are sold as "static phase converters" and they're simple and cheap and have a lot of imbalance problems. 

Switching phase converters work similarly to a VFD: They electronically manufacture the missing phase by PWM from a DC bus. It can handle any manner of unbalanced or sensitive loads because they're electronically generating three equal phases 120* out. The only difference in quality is how clean a sine wave you get.

These folks manufacture one style.


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## papaotis (Jun 8, 2013)

thank all you guys for your input. im having the poco look at the possibility of getting 208 from a major trans about 100' away. also havent heard back from the rest; owner. project im regretting! so far


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## sparkiez (Aug 1, 2015)

Heh, I was sitting there wondering why they didn't make IGBT phase converters a while back when I was looking into them.


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## papaotis (Jun 8, 2013)

today i was told the make-up air unit is run by the controls on the hood, which is 240v, not the 120 i wastold. guess that solves that one. the condensing unit on the walk-in is 208/230. that will work on 240 right? he's still screwed on steam table though the way i see it. details are coming VERY slowly in this place!


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## frenchelectrican (Mar 15, 2007)

papaotis said:


> today i was told the make-up air unit is run by the controls on the hood, which is 240v, not the 120 i wastold. guess that solves that one. the condensing unit on the walk-in is 208/230. that will work on 240 right? he's still screwed on steam table though the way i see it. details are coming VERY slowly in this place!


The air make up unit on single phase ? the motor wired on 240 volts ? 

That part you will need to look little closer to hood contol panel in case with ansal system.
( if you are using 240 tri phase becarefull with which phase you need to run for 120 v control. )

the condensing unit yuh .,, the 240 volt work just fine with 208/230 rating. single or tri phase ? 

Get couple coconuts rolling to that guy to speed up some info you are looking on steam table that will change the game plans.


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## telsa (May 22, 2015)

papaotis said:


> today i was told the make-up air unit is run by the controls on the hood, which is 240v, not the 120 i wastold. guess that solves that one. the condensing unit on the walk-in is 208/230. that will work on 240 right? he's still screwed on steam table though the way i see it. details are coming VERY slowly in this place!


Papa, is this the first restaurant you've messed with ?

S L O W information is the NORM. :laughing:


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## telsa (May 22, 2015)

This job has EXTRAS written all over it.

It's a Design & Redesign & Rebuild job.


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## papaotis (Jun 8, 2013)

first restuarant , no. first one this fudged up! and iv'e never had to deal with 208 except 3 phase. we dont have 3 phase and would be VERY expensive to get it there even thiugh there is a pad mount 100' away. it might run run the whole downtown, havent checked into that yet. there is a transformer not 40' away that only runs an a/c but theres so much chit around it i cant see all of the rating plate! i did see 208/120. but it is on anothers meter.:whistling2:


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## frenchelectrican (Mar 15, 2007)

papaotis said:


> first restuarant , no. first one this fudged up! and iv'e never had to deal with 208 except 3 phase. we dont have 3 phase and would be VERY expensive to get it there even thiugh there is a pad mount 100' away. it might run run the whole downtown, havent checked into that yet. there is a transformer not 40' away that only runs an a/c but theres so much chit around it i cant see all of the rating plate! i did see 208/120. but it is on anothers meter.:whistling2:



Ahh gotcha what ya saying .,,

that will be one heckva a challange on that.

I hope ya can find a way around this mess..


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## telsa (May 22, 2015)

Document the H out of this job.

You KNOW that the GC will deny how fouled up the flow of info was// is.


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## sbrn33 (Mar 15, 2007)

You should be able to convert the steam table to single phase pretty easily. Sounds like you got the rest taken care of. If not replace the motor on the MAU.


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