converting 110v 15a to 220v 20a

17 years ago

Hi,

Here are the facts of my present electrical set-up

Panel:

12 breakers of 110v/15a

1 breaker of 220v/15a

Building:

Former garage

converted into 4 units

3 residential units have one 110v breaker each

1 commercial unit(mine)has nine 110v and one 220 v breakers

Problem:

My unit is a theatre.

I presently have 8 small "daisy chained" dimmer packs which each run of off a 110v breaker.

Each dimmer pack has 4 dimmers, each of which will power various theatre lights (often 500w-1000w).

As you can imagine, because of the load limitations in the individual dimmer packs I have to do a lot of math in setting my light levels so that the cumulative draw on any 4 dimmer "family" (ie one breaker) never exceeds the 1600 watt limit.

Intended Solution

I would like to convert from

12 breakers of 110v 15 amp + 1 breaker of 220v 15 amp

6 breakers of 110v 15 amp + 3 breakers of 220v 20 amp.

Then I can get new dimmer packs with 8-12 dimmers each and run them off of my new 4400w breakers (as opposed to my previous puny 1600 breakers). Thus I will no longer need to micromanage the load on my 8 puny dimmer packs.

Questions:

1-Does my solution work? Is there any red flag I should look for in my breaker panel

(ie limits on moving from a 15 amp 220v breaker to a 20 amp? etc?)

2- I presume I need to turn off the master breaker before undertaking this work? (I know that might sound like a stupid question, but turning off the master breaker will affect the three other residential units that share my breaker panel)

3-From my reading here on the board this seems to be a fairly straightforward wiring job. If so what ballbark fee might I encounter in hiring a professional electrician? Or is it simple enough that I can do it myself?

Many thanks!

My theatre (and the works of W.Shakespeare which we stage) thank you!

Simon

Sort by:Oldest

Comments (8)

davidandkasie
17 years ago
since you have tenants, you cannot do the work your self. only single family owner occupied can be worked on by the owner.

sounds to me like the best bet would be to upgrade the service to all at the same time. you would probably get a better rate doing it all at once, than doing yours now and having to do the others later. and you just about can guarantee you will have ot do them at some point.
alchemytoronto
Original Author
17 years ago
David, thx for the reply.

Just to clarify, I need to leave the 3 tenants with their 3 existing 110v 15amp breakers (one each).

And I'd like to have a mix of 110v15amp and 220v20amp breakers for my theatre. Leaving myself 3 of the 110v breakers allows me to power the various 110v items in my unit.

Just wanted to clarify
Thx again
S
Related Discussions
countertop appliances - Is 220v more powerful?
Q
Comments (31)
Higher voltage does not inherently provide any more power but for a given current, higher voltage provides a linearly higher power assuming a zero power factor (i.e. pure resistive load). Safe wire guage requirements depend completely on current. What this means is if 12awg wire is considered safe for maximum current of 20A for the given length run, then having 240v on that circuit would provide twice the power as compared to a 120v circuit. So, given real world limitation and conditions, it can be said that more power can be delivered using higher voltage. As for efficiency, you have to look at the problem in another way. Given two 2400W appliances, one running on 120v and another running at 240v. The 120v would be running at 20A whereas the 240v would be running at 10A, again assuming zero power factor pure resistive load. That would result in the the 120v appliance having 4x the line loss (power lost to the transmission line) because P = I^2 * R. With a given resistance, double the current means quadruple the power. That said, the wire R is very low given large enough cabling so even quadruple the power is still very low compared to the delivered 2400W. BTW, this is the main reason high voltage transmission lines are used for long distances. US long distance high voltage lines are > 100kv (or even more than 200kv) which allow for a large amount of power with reasonably low current.
...See More
110/220 convertible table saw
Q
Comments (12)
The motor will run cooler and last longer on 240 V. The smallest wire you can use is #14. A 3 hp motor on #14 wire will have a slightly longer starting time since the voltage drop in the wires will be larger. The lower starting current on 240 V reduces the drop, allowing the motor to come up to speed more quickly. All the rules about current and voltage only apply if you can maintain the voltage at the motor terminals under all conditions. Start up is the worst since the motor is at stall and trying to come up to speed. Sears is very well known for exaggerating the horsepower of electric motors they sell. I have a Unisaw with a Baldor 3 hp motor. By Sears 'maximum developed horsepower' it would be over 60 hp. Repeated starts on 240 V require a 40 amp breaker.
...See More
Changing from 220V to 110V for Range
Q
Comments (21)
Here's an intriguing option: use the existing 240V wiring for one of the new over-the-range GE Advantium 240 microwave/speedcookers/convection ovens. Reuse the 120V/15A wiring for the gas stove ignition. The Advantium 240 line was just revamped. The new ones look and function as regular microwave ovens, but with 5500w available, can also double as a regular 2nd oven, or triple as a high-speed oven that combines microwave and halogen cooking to create quickly-cooked dishes that are crispy and don't have the usual soggy microwave taste and texture. You would need to downrate the breaker from 40A to 30A, but otherwise it should work easily.
...See More
How to fuse 220V/!5A device on 220V40A circuit
Q
Comments (22)
kensnh, really, if you think it's not safe, I won't do it. However, i do feel obliged to mention that eBay has nothing to do with this - I only referenced someone's EBay auction because the manufacturer's own website doesn't list the specifications and the guy selling the same thing on eBay did. But these devices are not devised by random charlatans on EBay, but rather (in this case) built and sold by Miele, a respected and esteemed appliance manufacturer who I assume wouldn't or couldn't sell unsafe merchandise. I wasn't actually planning to buy this on eBay, but rather directly from Miele or Bosch or their authorized retailers, and if need be have them drive out to my home and install it. The only thing different about my situation than that of a typical buyer is that instead of a 240V/30A outlet near the dryer, I have a 240V/40A outlet about 10 feet away. I thought, maybe, there would be some safe, legal way to use that to power a laundry appliance since it is currently unused. But if not, I can continue to use the more common 120V/15A washer I have now that plugs directly into the nearby outlet. It doesn't heat its own water and draws from the water heater tank, but I can continue to avoid using the washer and the shower at the same time. FWIW, I don't like using extension cords either. I'm very careful with the ones I do have - they're not dangling where they can get tripped on or squashed or have things fall on them. But I *do* tend to believe that if a respected major company sells something, it's probably safe. Not always, obviously.
...See More
Ron Natalie
17 years ago
Just to clarify, you can't do this. You can neither wire the commercial space nor the multifamily residence space. Even notwithstanding the law, theatre occupancies is no place for people to go guessing about the wiring rules.
alchemytoronto
Original Author
17 years ago
Ok (I presume you mean that I can't do this myself, and not that it can't be done?)
thx
greg_h
17 years ago
What you want to do is draw more power than you currently do. Whether that's possible or not depends on what your current service is (60amps, 100amps, 200amps) and what your overall electrical needs are.

If you were to get an electrician to simply do the changes you specified (ie. abandoning several 15A 120V circuits and wiring a couple of new 20A 240V circuits), then you may start tripping the main breaker. And you don't want that with a theater full of people.

So you need to hire an electrician to figure out what needs to be done to achieve the end results.
It may not be too much, but it may also require more extensive changes than you planned on.
bigblue
17 years ago
Only answer anyone can give you is to hire an electrician. It is illegal for you to do the work yourself, and there is much more information needed to answer your questions in the first place. Call an electrician to check this for you, as for pricing, call and get a few quotes for the work.
alchemytoronto
Original Author
17 years ago
I've spoken to an electrician friend of a friend and he's quoted 2hrs at $70/hr.

Thanks to everyone for their input.
Simon
alchemytoronto
Original Author
17 years ago
An update on where things ended up...

The electrician advised me that I have 100amps at 600v/3 phase which translates to 300amps at 110v. So I've got lots of power.

He's going to run a sub-panel from my breaker panel to my dimmers, and include 16-24 outlet plugs at 20amps/110v and a couple of 220v'ers.

He advised that we don't need to turn of the master power to the master breaker, and can leave the rental units with their power on while the work takes place.

He also informed me something fascinating about the dimmer packs. I had thought that if I have a 500 watt light plugged in, but I dim it to 10%, I would only be using 50 watts of power. Apparently this is not the case, and I continue to draw the full 500 watts. However only 50 watts goes to the light and the rest gets drawn by the dimmer pack. No wonder my electricity bill is so damn high.

In total he's advised me it will be one full day's work.

S

converting 110v 15a to 220v 20a

Comments (8)

davidandkasie

alchemytoronto
Original Author

Related Discussions

Ron Natalie

alchemytoronto
Original Author

greg_h

bigblue

alchemytoronto
Original Author

alchemytoronto
Original Author

COMPANY

BUSINESS SERVICES

GET HELP

CONNECT WITH US

converting 110v 15a to 220v 20a

Comments (8)

davidandkasie

alchemytorontoOriginal Author

Related Discussions

Ron Natalie

alchemytorontoOriginal Author

greg_h

bigblue

alchemytorontoOriginal Author

alchemytorontoOriginal Author

COMPANY

BUSINESS SERVICES

GET HELP

CONNECT WITH US

alchemytoronto
Original Author

alchemytoronto
Original Author

alchemytoronto
Original Author

alchemytoronto
Original Author