New range connected to 240v or 208v panel both 3 phase

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Nhrafan

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Company bought a new convection oven/range for the new break room. In the existing kitchen are the following two panels: panel1= 240V 3wire 3 phase and fed out of that panel, a panel directly next to it, panel 2= 120V/208v 4 wire 3 phase.

Paperwork with oven says:
120/240 volt 3 wire watts =8750/16500
120/208 volt 3wire watts= 7801/12500
40a or 50a power supply cord

My question is can I hook this into either panel (I'm thinking no on the 240 panel because the cover states it is 3 wire) and how is the other panel 4 wire if the main breaker for panel 2 is in panel 1 and panel 1 is 3 wire ??
I have not yet removed the covers to verify anything inside yet.
 
Sounds as if the labels are misleading.
You can feed the range from a 208v or 240 panel provided either (or both) have a neutral.
 
Nhrafan said:
Company bought a new convection oven/range for the new break room. In the existing kitchen are the following two panels: panel1= 240V 3wire 3 phase and fed out of that panel, a panel directly next to it, panel 2= 120V/208v 4 wire 3 phase.
Click to expand...

According to this you need to use the 208Y/120 connection. 3 phase, 3 wire has no neutral and you need 120 volts.
 
Welcome to the forum!


Nhrafan said:
Company bought a new convection oven/range for the new break room. In the existing kitchen are the following two panels: panel1= 240V 3wire 3 phase and fed out of that panel, a panel directly next to it, panel 2= 120V/208v 4 wire 3 phase.

Paperwork with oven says:
120/240 volt 3 wire watts =8750/16500
120/208 volt 3wire watts= 7801/12500
40a or 50a power supply cord

My question is can I hook this into either panel (I'm thinking no on the 240 panel because the cover states it is 3 wire) and how is the other panel 4 wire if the main breaker for panel 2 is in panel 1 and panel 1 is 3 wire ??
I have not yet removed the covers to verify anything inside yet.
Click to expand...

That's the first thing you need to do. If the 120/208V panel is fed directly from the 240V panel, something isnt right as it's impossible w/o 2 separate services or an intervening xfmr to have both 240 and 208. May just be a labeling issue, or panel 1 is serving as a wireway for panel 2's service conductors.

Ranges have required 4 wire cords since the 96 NEC. On a new install make sure if there is an internal bonding jumper in the range that you remove it first. You cannot wire this legally with a 3 prong cord, unless there happens to be an existing 3 prong range receptacle in the "new" break room.
 
JFletcher said:
Welcome to the forum!




That's the first thing you need to do. If the 120/208V panel is fed directly from the 240V panel, something isnt right as it's impossible w/o 2 separate services or an intervening xfmr to have both 240 and 208. May just be a labeling issue, or panel 1 is serving as a wireway for panel 2's service conductors.

Ranges have required 4 wire cords since the 96 NEC. On a new install make sure if there is an internal bonding jumper in the range that you remove it first. You cannot wire this legally with a 3 prong cord, unless there happens to be an existing 3 prong range receptacle in the "new" break room.
Click to expand...

No I have already run new 4 wire from above these boxes to the new location because of this. The wire is just coiled above and not in the panel yet, upon checking to see what new breaker I may need today is when I noticed the "3 wire" designation on the 240V panel. (Small stamped label from square d)
When I go in tomorrow I am going to remove the cover and see if there's a neutral in there and how the other panel is run with it.

Thank you all so far.
 
Nhrafan said:
how is the other panel 4 wire if the main breaker for panel 2 is in panel 1 and panel 1 is 3 wire ??
I have not yet removed the covers to verify anything inside yet.
Click to expand...

Because a neutral is derived for panel 2. This neutral is connected to ground and is the center of the Y 3 phase on panel 2.

Others please check me on this.
 
Nhrafan said:
No I have already run new 4 wire from above these boxes to the new location because of this. The wire is just coiled above and not in the panel yet, upon checking to see what new breaker I may need today is when I noticed the "3 wire" designation on the 240V panel. (Small stamped label from square d)
When I go in tomorrow I am going to remove the cover and see if there's a neutral in there and how the other panel is run with it.

Thank you all so far.
Click to expand...

Take a voltmeter and measure what you really have.
 
Took a closer look this morning and see that panel 1(240v) is feeding 3 wires out into hallway, into a transformer then back to panel 2 (208v)
There are 3 wires (2awg) feeding into transformer and 4 wires feeding from transformer into 208 panel.
So I assume I have to connect to 208 panel?
Will this degrade the range/oven performance though?
 
Nhrafan said:
Paperwork with oven says:
120/240 volt 3 wire watts =8750/16500
120/208 volt 3wire watts= 7801/12500
40a or 50a power supply cord
Click to expand...

Nhrafan said:
So I assume I have to connect to 208 panel?
Will this degrade the range/oven performance though?
Click to expand...

Somewhat less power but unless they are trying cook a turkey I doubt anyone will notice.

You said this was for a break room so I wouldn't think it will be a problem.
 
Nhrafan said:
Took a closer look this morning and see that panel 1(240v) is feeding 3 wires out into hallway, into a transformer then back to panel 2 (208v)
There are 3 wires (2awg) feeding into transformer and 4 wires feeding from transformer into 208 panel.
So I assume I have to connect to 208 panel?
Will this degrade the range/oven performance though?
Click to expand...

Does the transformer have enough capacity to add the range?

At 208 volt, the capacity of the range will be 75% of that at 240.
 
dkidd said:
Does the transformer have enough capacity to add the range?

At 208 volt, the capacity of the range will be 75% of that at 240.
Click to expand...

Most of this panel has things in it that are no longer used. I will be pulling out existing circuits to add this one in. Along with 2 fridges, an exhaust hood and an industrial coffee maker. The other things aren't used anymore and most can be disconnected.
 
growler said:
Somewhat less power but unless they are trying cook a turkey I doubt anyone will notice.

You said this was for a break room so I wouldn't think it will be a problem.
Click to expand...
It would still cook the turkey, it will just take a little longer for the oven to pre-heat.

The range burners will not get as hot, but as said, in a break room, I seriously doubt anyone will notice. If anyone cooks anything on the stove in our office, the smell draws in the scavengers, so you must be prepared to share whatever it is. Ergo, nobody uses it.
 
dkidd said:
Does the transformer have enough capacity to add the range?

At 208 volt, the capacity of the range will be 75% of that at 240.
Click to expand...

This is the transformer plate. The one that is between panel 1 and panel 2.
 

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Nhrafan said:
So I assume I have to connect to 208 panel?
Will this degrade the range/oven performance though?
Click to expand...

That is your only choice given the two panels. As others have stated the 208 volt connection reduces the output to 75% of the 240 volt supply.
 
Nhrafan said:
Took a closer look this morning and see that panel 1(240v) is feeding 3 wires out into hallway, into a transformer then back to panel 2 (208v)
There are 3 wires (2awg) feeding into transformer and 4 wires feeding from transformer into 208 panel.
So I assume I have to connect to 208 panel?
Will this degrade the range/oven performance though?
Click to expand...

I hope you will pardon the nature of my comments but I have to ask, are you thoroughly familiar with the design and nature of the power system in your building and why you have 240 3 phase and 208 3 phase in the same building?
I will say that I note that you are in PA and that means to me that you could be in an area that has some not so "standard" service arrangements from the POCO. For example, in some areas served by PECO and depending on the local distribution network they have in place there can be some unusual services by most standards. They may supply 240Y/139 volt service for purposes of creating a grounded service only which then requires the customer to create their own neutral to serve 120 volt loads or any other equipment that requires a neutral as could be your case. In some cases they will supply a 240 delta/with a center tapped neutral but won't allow you to use the neutral except for creating a grounded service.
You should have a thorough grasp of all the ramifications.
 
texie said:
I hope you will pardon the nature of my comments but I have to ask, are you thoroughly familiar with the design and nature of the power system in your building and why you have 240 3 phase and 208 3 phase in the same building?
I will say that I note that you are in PA and that means to me that you could be in an area that has some not so "standard" service arrangements from the POCO. For example, in some areas served by PECO and depending on the local distribution network they have in place there can be some unusual services by most standards. They may supply 240Y/139 volt service for purposes of creating a grounded service only which then requires the customer to create their own neutral to serve 120 volt loads or any other equipment that requires a neutral as could be your case. In some cases they will supply a 240 delta/with a center tapped neutral but won't allow you to use the neutral except for creating a grounded service.
You should have a thorough grasp of all the ramifications.
Click to expand...

Not a clue in all honesty because I just started working here this year. I am still figuring out how they set everything up day to day. We have 480v 277v 208v 120v panels. There's plenty of transformers and way too many panels to even count in this place. Luckily most/all are labeled as to voltages and things are labeled pretty good.
Where would I find out exactly what kind service supplies to the different areas?
We are a manufacturing facility with an office building and the building was expanded on multiple times over again.
 
Nhrafan said:
Not a clue in all honesty because I just started working here this year. I am still figuring out how they set everything up day to day. We have 480v 277v 208v 120v panels. There's plenty of transformers and way too many panels to even count in this place. Luckily most/all are labeled as to voltages and things are labeled pretty good.
Where would I find out exactly what kind service supplies to the different areas?
We are a manufacturing facility with an office building and the building was expanded on multiple times over again.
Click to expand...

I'm biased but it's great that you've found this forum. I for one would encourage you to keep posting things that may seem strange. As you can gather from the array of answers in this thread there are many knowledgeable people here to help you.:thumbsup:
 
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