480v to 240v?

[BellyUpFish]

Well, my wife bought an oven from someone she trusted.. "yep.. 240v"

Well, we were out of town and her brother went to get it.

Guess what? It's a 480v oven.

Anyone have any suggestions on getting it operating on 240v?

 

[Alan Douglas]

Two heating elements could be rewired in parallel instead of series. Fan motor? If it isn't dual voltage, that would have to be replaced. Temp controller?

 

[Norcal]

Well, my wife bought an oven from someone she trusted.. "yep.. 240v"

Well, we were out of town and her brother went to get it.

Guess what? It's a 480v oven.

Anyone have any suggestions on getting it operating on 240v?

Is it 3 phase? Some cooking equipment is not convertible to single phase, first thing would be to try & get some info from the manufacturer....

 

[wyliesdiesels]

Well, my wife bought an oven from someone she trusted.. "yep.. 240v"

Well, we were out of town and her brother went to get it.

Guess what? It's a 480v oven.

Anyone have any suggestions on getting it operating on 240v?

A 480v oven for residential use? Never seen one before. Are u sure its not for commercial or industrial use?

What is the amp draw @ 480v? The problem u may have is the current draw will double @ 240v and may be too much! Are u sure this is a single phase unit? Also, it may not be rated or listed for residential use! More info is needed!

 

[Socophreak]

Make, model will help you more. Sounds like a commercial unit, but we don't see that much 480v in commercial. More 208v 3Ph. The only 480v ovens we typically come across are in high output bakeries.

Wylie - check your math. Current is directly proportional to voltage. Your current draw will half and your power output it watts will be quartered.

 

[Norcal]

The fact that the oven is 480V means it's commercial cooking equipment, besides the voltage, we still do not know if it's 1Ø or 3Ø,or if the elements can be replaced, plus there are different clearances for commercial equipment compared to domestic, there are a lot of things wrong here.

 

[wyliesdiesels]

Make, model will help you more. Sounds like a commercial unit, but we don't see that much 480v in commercial. More 208v 3Ph. The only 480v ovens we typically come across are in high output bakeries.

Wylie - check your math. Current is directly proportional to voltage. Your current draw will half and your power output in watts will be quartered.

I thought ovens might be the same as motors. I guess I was wrong. With motors of the same HP, current draw doubles when the voltage is halved! Ex. a 1hp motor @ 230v draws 8a and @ 115v 16a.

 

[rlitman]

plus there are different clearances for commercial equipment compared to domestic, there are a lot of things wrong here.

THIS! Commercial ovens expect full stainless backsplashes, and have been known to set homes on fire when placed in a non-commercial kitchen that is not properly prepared.

 

[BellyUpFish]

I'd have to look up the oven info.

It's not for residential. It is a commercial oven.

My wife owns a bakery. You can watch her on FoodNetwork next week. LOL..

 

[pattenp]

I thought ovens might be the same as motors. I guess I was wrong. With motors of the same HP, current draw doubles when the voltage is halved! Ex. a 1hp motor @ 230v draws 8a and @ 115v 16a.

wylies, I'm with you on this. If a piece of equipment as an example is using 7200W @ 480V then that's 15A. If was 240V then the amps would be 30A. Maybe Socophreak was going the other way 240V to 480V to say the current would be halved.

 

[wyliesdiesels]

wylies, I'm with you on this. If a piece of equipment as an example is using 7200W @ 480V then that's 15A. If was 240V then the amps would be 30A. Maybe Socophreak was going the other way 240V to 480V to say the current would be halved.

Ok, so I'm not crazy! Yeah, maybe he thinks I was meaning 240v to 480v. But the OP wants to go 480v to 240v. So if this thing draws 50a @ 480v, then it might draw 100a @ 240v! Too much for residential use. Of course, that's if u use it on high. Regardless, I doubt its fire rated for residential use!

If I was the OP, I'd sell it on ebay or craigslist and buy a residential oven. Its not worth the hassle and possible house fire trying to get the darn thing to jive with a different electrical supply!

EDIT: I guess I missed the OPs post about the oven being used in a bakery!

 

[BellyUpFish]

Not for residential use.

 

[madosta]

Need more information I'm guessing.

Make and model of the oven?
Heating coils?
Fan?
Lights?
Commercial space?
No transformers already?
Step up transformer?
Retrofit with 240v heating elements?
Enough 240v amp capacity?

I'm sure there is someone on here that can tell you either way now that we know it's being used in a commercial application, but then you're supposed to have a licensed electrician to work on that stuff.

 

[W-Cummins]

You may be able to convert it to 240V from 480V. It may be as easy as a simple reconnection of the heating elements, or as in my case (want to go to 480V) a TOTAL replacement of almost all the the components of the oven. For my Blodgett combi oven, I would have had to replace, all of the 8 oven elements, the 3 boiler/steam generator elements, the convection motor and the drain pump! I'm still kicking myself for not buying the 480v oven for more $$ than the 208V one I have but ya know how that ole hind sight goes!
BTW the 1/2 current deal makes a BIG change as to the cost of connection, I could have used 10 gauge wire and a 30 amp outlet and plug that I have dozens of, VS a 60amp $300 pin and socket set and $100 worth of wire!

William....

 

[madosta]

There's an article here about going from 240v to 480v:

http://www.smihq.org/public/publications/07_45_02/_preventive .html

... it is easy to convert the wiring if the number of elements is an even number and divisible by three (six, 12, 18, 24, etc…elements). The 240V elements can be wired in pairs for 480V operation. The net change in wiring from 240V to 480V is a subtraction of wires; usually half the wires can merely be pulled out. Unfortunately, it is not so easy to convert a 480V oven to 240V. In this case you have to add wires, and it is not easy to snake new wires back through an oven’s shell. Often, you will have to temporarily remove the top of the oven as well as some insulation. Although it is possible to change element wires yourself, you have to make sure other components in the oven are also changed...

 

[rlitman]

You're forgetting that you are now running double the current through the switches and wiring harness that are not rated for it.

It is easy to convert the heating elements to use half the voltage, but a range is more than just heating elements.

 

[wyliesdiesels]

Not for residential use.

I guess I missed your post about the oven being used in a bakery!

You're forgetting that you are now running double the current through the switches and wiring harness that are not rated for it.

It is easy to convert the heating elements to use half the voltage, but a range is more than just heating elements.

Good point. Wire gauges and current ratings of switches, relays, components, etc. will be wrong when running @ half the voltage.

Ok, so since this unit is being used in a bakery, why not install a step up transformer? That will be a whole lot easier than trying to convert the oven for 240v use. A few potential issues though: if the oven is 3Ø and your electrical service is 1Ø, then the only way to possibly hook it up would be with a rotary phase converter. But that would be silly for use in a bakery!

So the BIG question here is, is the oven 3Ø or 1Ø and if 3Ø then is your electrical service 3Ø?

 

[BellyUpFish]

Manufacturer will gladly sell us the required parts to swap the 480v for 240v for $2,000.

May have to go that route. Still have less than half a new oven in it.

 

[wyliesdiesels]

Manufacturer will gladly sell us the required parts to swap the 480v for 240v for $2,000.

May have to go that route. Still have less than half a new oven in it.

Get a quote for a step up transformer installation! It may be cheaper than the cost and pain of swapping parts!

 

[rlitman]

Just putting a crazy question out there, but is it possible to get 480V to it?
I'm not used to seeing a commercial building that doesn't have 3Ø with a 480V feed and a stepdown transformer.
If you can get to 480V, the wiring will be much cheaper, even forgetting about the cost of the parts swap.

 

[wyliesdiesels]

It all depends on the building and what it was set up for! I've hardly ever seen 480v in a commercial building. However, a few times I've seen what use to be an industrial building that was converted to commercial and still had 480v service. We definitely need more info from the OP to know for sure! We don't even know the location of the OP, so who knows!

 

[BellyUpFish]

Get a quote for a step up transformer installation! It may be cheaper than the cost and pain of swapping parts!

We got a quote from TemCo and they want more for the transformer than the cost of the parts. Something like $3,800 compared to $2,000.

Just putting a crazy question out there, but is it possible to get 480V to it?
I'm not used to seeing a commercial building that doesn't have 3Ø with a 480V feed and a stepdown transformer.
If you can get to 480V, the wiring will be much cheaper, even forgetting about the cost of the parts swap.

Yeh, we tried. City engineer blew us out of the way.

It all depends on the building and what it was set up for! I've hardly ever seen 480v in a commercial building. However, a few times I've seen what use to be an industrial building that was converted to commercial and still had 480v service. We definitely need more info from the OP to know for sure! We don't even know the location of the OP, so who knows!

The building is currently not a 3 phase and the city engineer says we can't get 3 phase run to it.

We are located in Florence, Alabama.


Here are the spec sheets from her oven..

 

[wyliesdiesels]

Ok, sorry if u already answered this but is this oven 3Ø? I can't tell looking @ the wiring schematic u posted cause the resolution is too small/poor but the KW chart for single phase @ 240v says 47.9a so I'd be willing to bet that if u rewired 480v elements to run on 240v, amperage draw would double! And since a transformer is so darn expensive(I didn't realize they were; I've installed many of 'em @ work but I've never done the billing for 'em so I had no idea!), I guess you're best bet is to order the parts to switch it over! That is if its not 3Ø!

BTW, 3 phase would be more expensive to put in(pole or pad mount transformer(s), service main/meter, wire, step-down transformer for existing equipment, permits, inspections, etc.) vs. buying the parts to change it over to 240v!

 

[rlitman]

Yes it would. Also, there are power losses at the transformer that would cost you year in and out if you went with a step up. Just rewire it the right way.

 

[nehog]

The chart shows single phase, 240 volts as an option. However, it is not clear (nor is the diagram!) if voltage can be adjusted without replacing the elements (and a few other parts). It shows with single phase setup, 240 volts you are looking at just under 50 amps, which is doable.

OK, the parts breakdown is clear: you will need new elements, and a bunch of other parts to make this work on 240 volts.

 

[Socophreak]

Manufacturer will gladly sell us the required parts to swap the 480v for 240v for $2,000.

May have to go that route. Still have less than half a new oven in it.

Nvm didn't look at the specs. We usually turn and run the Other way when we see Lang. Return it and buy a garland MCO series. I don't know specific costs, but I can tell you of several very old MCO ovens still running in my city.

Why not a gas oven? If you have the provisions, gas will typically be cheaper.

 

[mrb]

i have a huge 240v - 480v single phase transformer...its a 50 or 75kva. I dont know what freight would cost to alabama though.... :/