# 208V three-phase motor on a 220V three-phase feed.



## aaronmen (Apr 2, 2013)

I'll start by saying I'm not an electrician or an electrical engineer. I mostly deal in low voltage circuitry having to do with integration of security electronic systems. This is also my first post.

Anyway, I'm working on a project in Mexico, and my system is controlling some large vehicle gates that require 208V three-phase feed for the motor.
The facility ran what they say is 220V three-phase and they tell me the transformer is in a wye config.

The gates are not operating (they're is hooked up, but only the low-voltage controls circuit board of the gate is working, not the motor itself). So obviously the 220 is connected and feeding a power supply (part of the gate assembly) that has no problem with the 220V, but the gate motor itself is really that sensitive to 12V extra? My controls system is only providing dry contacts and the gate controller passes low-voltage signals through my contacts thereby operating the gate when my contacts change position (controlled by a PLC).

We measure between 219-222VAC between phases for the feeder circuit. Would that really be enough to not start a 208 3-phase gate, or am I missing something?
The electricians on site seem to think the gate should work just fine with the voltage levels they provide. I'm not sure if if 220 3-phase is standard though. Perhaps the gate is meant for U.S. installations and won't work with the extra voltage?

Some insight would be appreciated. Thanks.


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## HawkShock (Nov 27, 2012)

Shake some of the volts out of the wire, it should look like a few sparks. Then it should work fine. 

But seriously, what does the motor plate say?

If there are electricians on site, it doesn't seem to be your problem.


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## aaronmen (Apr 2, 2013)

HawkShock said:


> Shake some of the volts out of the wire, it should look like a few sparks. Then it should work fine.
> 
> But seriously, what does the motor plate say?
> 
> If there are electricians on site, it doesn't seem to be your problem.


Well, it was our sub that supplied the gate. The motor plate says 208V 3-phase.
The electricians (from Mexico, in Mexico) say that their 220VAC should work fine, but I don't know that I trust their judgment - they've had a lot of power problems on this project.
I guess what I would like to know is if three phase motors care if its 208 vs 220 vs 240, or if the feeder transformer is Wye vs Delta.


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## HawkShock (Nov 27, 2012)

aaronmen said:


> Well, it was our sub that supplied the gate. The motor plate says 208V 3-phase.
> The electricians (from Mexico, in Mexico) say that their 220VAC should work fine, but I don't know that I trust their judgment - they've had a lot of power problems on this project.
> I guess what I would like to know is if three phase motors care if its 208 vs 220 vs 240, or if the feeder transformer is Wye vs Delta.


Well, to answer your question, yes, they care. How much they care depends on what motor it is. Look up the part number or call the manufacturer. I can't help without more info, and even if you gave me the info, I wouldn't look it up for you, I'm not getting paid to do it.:thumbsup:
Did you read the agreement when you signed up for an account? This forum is for Electricians.
Prepare for lockdown.


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## Wirenuting (Sep 12, 2010)

aaronmen said:


> Well, it was our sub that supplied the gate. The motor plate says 208V 3-phase.
> The electricians (from Mexico, in Mexico) say that their 220VAC should work fine, but I don't know that I trust their judgment - they've had a lot of power problems on this project.
> I guess what I would like to know is if three phase motors care if its 208 vs 220 vs 240, or if the feeder transformer is Wye vs Delta.


In a good world a 200 volt motor is used in a 208 system. A 200 volt motor would run, but not as long on a 240 system. 
They need to tell you what the motor is... It's a rare motor that says 208/3ph... 
After that, did they wire it correctly and what are the o/l's set at?

Have them send a picture of the data plate.


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## aaronmen (Apr 2, 2013)

Wirenuting said:


> In a good world a 200 volt motor is used in a 208 system. A 200 volt motor would run, but not as long on a 240 system.
> They need to tell you what the motor is... It's a rare motor that says 208/3ph...
> After that, did they wire it correctly and what are the o/l's set at?
> 
> Have them send a picture of the data plate.


Thanks Wirenuting. I'll have them get me a photo of the actual plate. When they told me 208 3 Phase, that was what the model was listed as in the manual. I plan to get on the phone with the manufacturer tomorrow.
I appreciate your insight.

HawkShock, I'm not expecting or even hoping that anyone will review anything beyond what's already in their knowledge bank. Though I'm not an electrician, I've studied electronics and have certificates in low voltage electronics from my local college. I simply had a question regarding 3 phase motors which I'm not as familiar with. Regardless, if I'm bounced, I'm bounced. It was fun while it lasted.


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## Wirenuting (Sep 12, 2010)

aaronmen said:


> Thanks Wirenuting. I'll have them get me a photo of the actual plate. When they told me 208 3 Phase, that was what the model was listed as in the manual. I plan to get on the phone with the manufacturer tomorrow.
> I appreciate your insight.
> 
> HawkShock, I'm not expecting or even hoping that anyone will review anything beyond what's already in their knowledge bank. Though I'm not an electrician, I've studied electronics and have certificates in low voltage electronics from my local college. I simply had a question regarding 3 phase motors which I'm not as familiar with. Regardless, if I'm bounced, I'm bounced. It was fun while it lasted.


We sometimes beat up on members that aren't electricians... It's in the sites TOS... But to be fair it's mostly home owners and DIY'ers that get chased the most.... It's a liability thing. A mod will point them, to the do it yourself side and lock them out. 

IMO, you can stay if you make a coffee and donut run. 


Swing to the intro thread and say hi to everyone.


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## ponyboy (Nov 18, 2012)

not sure what they got down there in mehico but a true 220 volt system probably isn't what you'll find. many motors have a 10% allowable variance between supply and utilization voltages. if the motor is calling for 208 then 220 should work if thats what you have. if you truly have 240 volts then there is definitely an issue. either way i would think you'd have some sort of mechanical reaction from the motor assuming everything is wired correctly, and you said nothing at all happens??


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## Wirenuting (Sep 12, 2010)

ponyboy said:


> not sure what they got down there in mehico but a true 220 volt system probably isn't what you'll find. many motors have a 10% allowable variance between supply and utilization voltages. if the motor is calling for 208 then 220 should work if thats what you have. if you truly have 240 volts then there is definitely an issue. either way i would think you'd have some sort of mechanical reaction from the motor assuming everything is wired correctly, and you said nothing at all happens??


He does prison stuff so they need to empty the place before the gates can work. 
You know how it can be.


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## ponyboy (Nov 18, 2012)

Wirenuting said:


> He does prison stuff so they need to empty the place before the gates can work.
> You know how it can be.


i've been known to locate certain things from time to time


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## HawkShock (Nov 27, 2012)

ponyboy said:


> i've been known to locate certain things from time to time


Thanks, Red.


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## ponyboy (Nov 18, 2012)

HawkShock said:


> Thanks, Red.


get busy livin or get busy dyin brotha!


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## micromind (Aug 11, 2007)

If the motor is actually 208 volts, and not 208-230/460 volts, then if it is supplied by a 220 volt system, the current will be fairly high. Maybe high enough to trip the overloads when in fact, it is not actually overloaded. 

Also, do the controls work? By that I mean do the controls try to start the motor but the motor won't run? 

Finally, if the motor rotation was wrong when first installed, it's usually important to change it at the incoming lines, not at the motor. the reason being that the limit switches are designed to operate in one direction only. If the motor turns wrong, they will have no effect, and the motor will jam. Possibly bending or breaking the gate mechanism.

P.S. If the actual voltage is indeed 220, and it is a wye connection, the voltage to neutral/ground will be 127 instead of 120. Not horrible, but not good either.


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## aaronmen (Apr 2, 2013)

micromind said:


> If the motor is actually 208 volts, and not 208-230/460 volts, then if it is supplied by a 220 volt system, the current will be fairly high. Maybe high enough to trip the overloads when in fact, it is not actually overloaded.
> 
> Also, do the controls work? By that I mean do the controls try to start the motor but the motor won't run?
> 
> ...


Yes, I know the site's single phase circuits measure at 127V rather than 120 , except of course on the UPS backed circuits which are regulated to 120.

I need to find out if the motor is even trying to start. I was told they aren't getting anything, but that could mean several things.
I'll update this post when it's resolved.
I appreciate everyone's input.

Fortunately this is a brand new facility, so no inmates yet.


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## Southeast Power (Jan 18, 2009)

aaronmen said:


> I'll start by saying I'm not an electrician or an electrical engineer. I mostly deal in low voltage circuitry having to do with integration of security electronic systems. This is also my first post.
> 
> Anyway, I'm working on a project in Mexico, and my system is controlling some large vehicle gates that require 208V three-phase feed for the motor.
> The facility ran what they say is 220V three-phase and they tell me the transformer is in a wye config.
> ...


You must have some control circuit rejecting the voltage, the motor would not know and just turn if its good. Can you force a contractor closed to test the motor? If it works its your fancy control board rejecting the power. Can you prove that 220 is a wye voltage?


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## micromind (Aug 11, 2007)

aaronmen said:


> Yes, I know the site's single phase circuits measure at 127V rather than 120 , except of course on the UPS backed circuits which are regulated to 120.
> 
> I need to find out if the motor is even trying to start. I was told they aren't getting anything, but that could mean several things.
> I'll update this post when it's resolved.
> ...


It's also possible that there's a control transformer involved, most controls are either 120 or 24. If so, it's possible that the higher voltage saturates the core, thus driving the current into the stratosphere, and very likely blowing the primary fuses. Or one of them anyway. 

Inrush current at high voltage can sometimes blow a transformer fuse too.

Yet another possibility is that if a phase failure relay is installed and the phase rotation is backward, the controls will be locked out. swap two of the incoming lines and see if that solves the problem.


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## runruh (Sep 19, 2012)

I've connected a few circuits in the Latin countries. More in Central and South America than Mexico. One thing I noticed is that many times when you expect to get three phase you get what is called an open delta. If you have two transformers on the pole instead of three that is what you have. Regardless of your setup the motor should try to run if the supply voltage is applied to the motor leads. Maybe your "electricians" don't understand motor controls. Espero tu encuentra la solucion pronto.


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## wireman64 (Feb 2, 2012)

aaronmen said:


> I'll start by saying I'm not an electrician or an electrical engineer. I mostly deal in low voltage circuitry having to do with integration of security electronic systems. This is also my first post.
> 
> Anyway, I'm working on a project in Mexico, and my system is controlling some large vehicle gates that require 208V three-phase feed for the motor.
> The facility ran what they say is 220V three-phase and they tell me the transformer is in a wye config.
> ...


Ive been to mexico and seen the electrical work there, if i where you i would first check to see if the motor was even hooked up right in the first place !


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## 220/221 (Sep 25, 2007)




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