Discussion of Voltage and Amperage

[rocknroll baker]

I ended up here as I was searching for info on the relationship between voltage and amperage.
Please forgive any spelling, grammatical or terminology errors.
I own a bakery and from time to time I need to purchase equipment.
I recently found an ancient dough mixer that was stuck in the corner of a bakery that had closed.
The electrical plug had been disconnected and the cable was just bare with the exposed copper leads.
The vendor offered the mixer to me at a very good price, I countered that while I loved his price I needed to ascertain that the mixer actually worked.
He was able to get an electrician in to take a look.
The electrician was able to get the machine working but told the vendor that it requires 600 volts to operate properly.
The vendor passed this information on to me and now I am trying to figure out whether or not I will be able to run at my location.
I examined the electrical panel at my bakery, here is what it says:
"Volts AC/CA 120/24
200 Amps
3 Phase"
I called my guy, a certified electrician, to see if it would be possible to use this piece of equipment in my shop.
He told me that yes it could be done (on earth as it is in heaven), but would require us getting access to the main electrical room of the plaza where my shop is located.
He would run a line from my unit to the electrical room and hook up to the main panel there.
He briefly explained the relationship between volts and amps as one where if there is high voltage there is usually lower amps and vice versa.
I am trying to understand this relationship in order to make some decisions about how to proceed.
I would appreciate any comments to explain.
Since the mixer is quite old, probably at least 50 years, I am wondering if it was more common in times gone by to run an electric motor that required a lot of low end torque on higher voltage.
???
Thanks,
rocknroll baker

 

[dhrivnak]

Typically if you double the voltage you can halve the amps to get the same power as power is Voltage*Amps.

Because you panel and system is set up on 240V I can see the need to pull a separate 600V service to power the mixer.

 

[rocknroll baker]

I ended up here as I was searching for info on the relationship between voltage and amperage.
Please forgive any spelling, grammatical or terminology errors.
I own a bakery and from time to time I need to purchase equipment.
I recently found an ancient dough mixer that was stuck in the corner of a bakery that had closed.
The electrical plug had been disconnected and the cable was just bare with the exposed copper leads.
The vendor offered the mixer to me at a very good price, I countered that while I loved his price I needed to ascertain that the mixer actually worked.
He was able to get an electrician in to take a look.
The electrician was able to get the machine working but told the vendor that it requires 600 volts to operate properly.
The vendor passed this information on to me and now I am trying to figure out whether or not I will be able to run at my location.
I examined the electrical panel at my bakery, here is what it says:
"Volts AC/CA 120/24
200 Amps
3 Phase"
I called my guy, a certified electrician, to see if it would be possible to use this piece of equipment in my shop.
He told me that yes it could be done (on earth as it is in heaven), but would require us getting access to the main electrical room of the plaza where my shop is located.
He would run a line from my unit to the electrical room and hook up to the main panel there.
He briefly explained the relationship between volts and amps as one where if there is high voltage there is usually lower amps and vice versa.
I am trying to understand this relationship in order to make some decisions about how to proceed.
I would appreciate any comments to explain.
Since the mixer is quite old, probably at least 50 years, I am wondering if it was more common in times gone by to run an electric motor that required a lot of low end torque on higher voltage.
???
Thanks,
rocknroll baker
PS:
Here is a youTube video showning a similar mixer in action.
They are a very early design, european in origin.
http://youtu.be/Ol4U3IPHpkI

 

[FlasherZ]

I am trying to understand this relationship in order to make some decisions about how to proceed.
I would appreciate any comments to explain.

The relationship between potential (measured in volts) and current (measured in amps) is like water... Voltage is the water pressure, while current is the flow volume. While there are some relationships between the two (Ohm's law and Joule's heating law), for an appliance you need to have the correct voltage to power the appliance, and sufficient capacity to handle the current. Too much voltage will let the magic smoke out of most devices, while too little will cause motors to stall or overheat.

It is true that when you use higher voltage, for the equivalent power (Joule's heating law) you need less current, as power (watts) = volts x amps. Wire size (thickness) is determined by the current (number of amps). So for higher voltage, you can use smaller wires. Power-hungry appliances in commercial and industrial areas, then, will use higher voltages if possible (especially for heavy-duty motor loads) to reduce the wire size required.

In Canada, 600VAC L-L 3-phase is an industrial standard, equivalent to 480VAC L-L 3-phase in the US. You will find this in heavier industrial and commercial areas. As your electrician says, he suspects the main distribution center for your plaza is fed with 600VAC but that your shop is fed via a smaller transformer to give you the 240V and 120V you need for "normal" appliances. He will be able to provide you with a connection to power that mixer, but he will likely have to do some significant work to do it - depending upon where your meter is and how things are connected, he may need to swap some things around to make it work. I'd say you need to get your electrician to give you an estimate or quote on the work that would need to be done.

 

[rocknroll baker]

Thanks Flasher, good analysis, this will help in moving my project forward
-rnr b

 

[AudubonB]

Crikeys! Whatever machine you found, that will make my 50 qt. Hobart look like a countertop KitchenAid! Fire it up and watch Toronto's lights dim!

 

[mknox]

Further to what FlasherZ says, there may be a bit more to it than that (I worked for Toronto Hydro for 21 years). Toronto used to have a lot of 600 volt delta (3-wire) equipment as opposed to 347/600 volt three-phase, 4-wire. Usually, around here, when someone says 600 volts, they are referring to the delta configuration.

It sounds like your bakery has a 200 amp single phase service. In spite of the 120/240 volt designation on the equipment, it could possible be 120/208 volts (2-phases plus neutral). Toronto supplies a lot of strip malls and such with 120/208 volts three-phase, 4-wire transformers, and supplies 2 of three phases plus neutral to the smaller units that don't require 3-phase service. Some of the really old buildings had both 120/240 volt and 600 volt delta services. Toronto Hydro may allow a second 600 volt service to your unit if there is 600 volts in the building. It might also be possible to supply your unit with 120/208 volt three-phase power, then have your electrician install a small dry-type transformer to step the voltage up to the mixer's requirements.

My advice: call Toronto Hydro and find out what they have in the building and what they'll allow as far as servicing this mixer goes. Just because an electrician says it can be done, doesn't mean the utility will allow it, or that there's capacity on the system.