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Old 03-01-2019, 12:59 AM   #16
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Re: 240/120 stepdown transformer


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Originally Posted by AllanJ View Post
If the exact transformer you get is not rated for 30 amps at 240 volts on the primary (to match your circuit) then you need either primary overcurrent protection in the transformer "extension cord" or you need to downgrade the breaker at the feeding panel (in your living space).
Thank you--that's good information. Assuming I can get away with this at all, it sounds like I'll have to install a subpanel that splits the 240v line, with separate breakers for the A/C and transformer. That's not a big problem.

I checked the compressor specs and the fusebox, and the A/C has a "min circuit" rating of 19.3 amps, and the fuse is at 25A. Since the feed is 30A, I do have some amount of margin there.

I guess the only remaining question is if the subpanel serves to put the A/C on a dedicated circuit as far as code is concerned. I'd think it would, since it seems that the defining feature of a circuit is that there is an overcurrent device between it and the feed. The A/C would indeed get its own 25A breaker here.
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Old 03-01-2019, 04:20 AM   #17
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Re: 240/120 stepdown transformer


I'm with curious. You came here knowing what you want to do is foolish but cheap and you are falling for the old "I can stumble along with cheap for a while" and what you are looking for is confirmation from us that cheap is good.

It's not. Your going to likely cause a fire or burn up the transformer or be stumbling over it. Transformers are inefficient beasts. They use them in power distribution because they have to.

You own this place. If you were in an apartment I'd say have at a transformer solution until your lease runs out and you can move to a better place. But you own this and how long are you going to live in it? Years? The rest of your life?

Get an electrician in and pull multiple circuits, a 50A one for your EV and a 30A 240v with neutral one for your shop and a 20A 120v. Then for the rest of your life you won't be bothered.

Sure it may suck up $5k. But in the future the HOA may decide to pass rules making it impossible for you to pull anything. And with a 50A outlet for an EV charger your condo well in the future that's probably going to add a good $20k or more in equity. Maybe more. In fact for me, if I was shopping for a condo (shoot me if that ever happens) it would be a make-or-break deal - I won't buy a dwelling without the ability to run a 50A 240v line for an EV charger. And I don't even have an EV now.

It's not your job to present anything to an electrician. They are big boys. Call one and tell him here's where the stuff is, here's your restrictions, here's what I want, tell me what it costs. If he says "I can't" then tell him to get lost and call the next one in the book. Not all electricians are going to wuss out of a sticky job. The best ones will love the challenge and are a bit of an ass anyway and will tramp through other people's units with impunity. If the next HOA meeting resembles an arena of angry cats because of what you did you can tell them that's what you get when you don't allow outside conduit - either change that rule or live with the disruption when the next guy does it. It's just drywall and drywall was designed to be gutted out and replaced for just this kind of issue.
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Old 03-01-2019, 04:35 AM   #18
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Re: 240/120 stepdown transformer


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Originally Posted by tmittelstaedt View Post
I'm with curious. You came here knowing what you want to do is foolish but cheap and you are falling for the old "I can stumble along with cheap for a while" and what you are looking for is confirmation from us that cheap is good.

It's not. Your going to likely cause a fire or burn up the transformer or be stumbling over it. Transformers are inefficient beasts. They use them in power distribution because they have to.

You own this place. If you were in an apartment I'd say have at a transformer solution until your lease runs out and you can move to a better place. But you own this and how long are you going to live in it? Years? The rest of your life?

Get an electrician in and pull multiple circuits, a 50A one for your EV and a 30A 240v with neutral one for your shop and a 20A 120v. Then for the rest of your life you won't be bothered.

Sure it may suck up $5k. But in the future the HOA may decide to pass rules making it impossible for you to pull anything. And with a 50A outlet for an EV charger your condo well in the future that's probably going to add a good $20k or more in equity. Maybe more. In fact for me, if I was shopping for a condo (shoot me if that ever happens) it would be a make-or-break deal - I won't buy a dwelling without the ability to run a 50A 240v line for an EV charger. And I don't even have an EV now.

It's not your job to present anything to an electrician. They are big boys. Call one and tell him here's where the stuff is, here's your restrictions, here's what I want, tell me what it costs. If he says "I can't" then tell him to get lost and call the next one in the book. Not all electricians are going to wuss out of a sticky job. The best ones will love the challenge and are a bit of an ass anyway and will tramp through other people's units with impunity. If the next HOA meeting resembles an arena of angry cats because of what you did you can tell them that's what you get when you don't allow outside conduit - either change that rule or live with the disruption when the next guy does it. It's just drywall and drywall was designed to be gutted out and replaced for just this kind of issue.
Without the HOAs pre- authorization of the procedure, they usually have the lawful ability to demand that you rip it back out and repair the damage at your expense. HOA can get quite nasty. In this case they are more of a board of directors of a condo Corp, which will give them more power. They could even go so far as outlawing "workshop" activities in the garages. (Being a contractor for many condos, I've heard lots of stories.)

I always stress caution when dealing with them in these situations. I agree that pulling new cable would be a great option, and with a whole plan laid out they may just approve it. Yes it wouldn't be cheap up front, but it would be approved which would definitely add a bunch to the equity of the condo. (I also would pay more, and I also don't have an EV.)

Cheers!
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Old 03-01-2019, 04:50 AM   #19
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Re: 240/120 stepdown transformer


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Originally Posted by tmittelstaedt View Post
You came here knowing what you want to do is foolish but cheap and you are falling for the old "I can stumble along with cheap for a while" and what you are looking for is confirmation from us that cheap is good.
No, I'm looking to explore my options--but I'm also looking for realistic downsides, not scaremongering. There's zero reason why a properly installed transformer should be a fire hazard.

Quote:
Originally Posted by tmittelstaedt View Post
Sure it may suck up $5k.
If I knew I could get it done for that, without burning too many hours of my own time rotating through contractors, I would. However, I suspect it would be substantially more than that. My main feed is only 90A, so I'm obviously not getting another 50A out of that, let alone 20A.

The solution here would be to install a second meter in the building's electrical room and a new main panel in the garage. I've asked the HOA for the architectural drawings to see if this is possible--I can't figure out the geometry without some help here. They haven't gotten back.

Fortunately, I live in California, where HOAs are required to allow wiring upgrades for EV systems. And they can't just stall forever, either--the law sets time limits to their objections. But they aren't required to allow just anything, either.

Quote:
Originally Posted by tmittelstaedt View Post
It's just drywall and drywall was designed to be gutted out and replaced for just this kind of issue.
Remember, there's at least one neighbor in the way. Maybe I can slip him $500 for the disruption in running more line, but I'd really rather not have to do that. Running line for an entirely new meter and panel would probably go through several neighbors.
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Old 03-01-2019, 04:52 AM   #20
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Re: 240/120 stepdown transformer


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Originally Posted by supers05 View Post
Without the HOAs pre- authorization of the procedure, they usually have the lawful ability to demand that you rip it back out and repair the damage at your expense. HOA can get quite nasty. In this case they are more of a board of directors of a condo Corp, which will give them more power. They could even go so far as outlawing "workshop" activities in the garages. (Being a contractor for many condos, I've heard lots of stories.)

I always stress caution when dealing with them in these situations. I agree that pulling new cable would be a great option, and with a whole plan laid out they may just approve it. Yes it wouldn't be cheap up front, but it would be approved which would definitely add a bunch to the equity of the condo. (I also would pay more, and I also don't have an EV.)

Cheers!
I was wondering if they already outlaw "workshop" activities in garages. The condo my MIL lived in when she was still alive even outlawed people doing their own oil changes in their car spaces. They were paranoid about junk cars. The funny thing was that her car was non-running (dead battery and she didn't drive but refused to sell it) for 3 years and nobody complained.

He said their policy was no preauth was needed on electrical work as long as it was done by an electrician. But like you I would also suggest going to an HOA meeting and bringing up "I want to add an electric car outlet to my garage" and get their response. It will go down in the minutes even if it's just a voice affirmation that no permission is needed. Once that's there, it would be impossible for them to force him to tear out anything. And furthermore, even if they did threaten him to tear out anything he can merely tell his neighbor "OK I will tear it out which means you will have yet another week of them sawing out your drywall and dust all over and patching and such when you would rather be sitting in your bathrobe drinking your morning coffee" That will get that shut down right quick.

The HOA may vote after the fact to block this kind of activity but they won't be able to screw him over even though they may hate him. But the reality of it is that everyone living in that condo who has a garage is in the same boat about electric cars. They probably all have wiring in each others units and explaining that "you put up with my sheet when I do it and I will put up with your sheet when you do it and we both will forget the inconvenience when the money comes when it's time to sell" can go a long way. Greed and avarice are good companions when it comes to motivating people to do anything.
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Old 03-01-2019, 05:24 AM   #21
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Re: 240/120 stepdown transformer


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Originally Posted by SyzygyRhythm View Post
No, I'm looking to explore my options--but I'm also looking for realistic downsides, not scaremongering. There's zero reason why a properly installed transformer should be a fire hazard.



If I knew I could get it done for that, without burning too many hours of my own time rotating through contractors, I would. However, I suspect it would be substantially more than that. My main feed is only 90A, so I'm obviously not getting another 50A out of that, let alone 20A.

The solution here would be to install a second meter in the building's electrical room and a new main panel in the garage. I've asked the HOA for the architectural drawings to see if this is possible--I can't figure out the geometry without some help here. They haven't gotten back.

Fortunately, I live in California, where HOAs are required to allow wiring upgrades for EV systems. And they can't just stall forever, either--the law sets time limits to their objections. But they aren't required to allow just anything, either.



Remember, there's at least one neighbor in the way. Maybe I can slip him $500 for the disruption in running more line, but I'd really rather not have to do that. Running line for an entirely new meter and panel would probably go through several neighbors.
Well like I posted already you merely explain to all of them that if they let you do this without objections you won't object when they want to do it for themselves and all of you get an equity boost. And the icing on the cake is you can explain the law to the holdouts. It's been observed that you can get more with a kind word and a 2 x 4 than just a kind word. Of course you don't say your going to run several cables besides the EV one. That's something you add in to the job 4 days before the electrician arrives and "forget" to inform the HOA about. Like they would care anyway.

You probably won't get drawings from the HOA. Just go to the county and look up the original building permits and the architectural firm is going to be on them, and go to that firm and they will have them.

"properly installed" transformer typically means 3 to 4 times the wattage of a motor driven power tool. So your 400 watt drill needs a 1600 watt transformer. This is because the inrush current on these devices is very high and the transformer can be destroyed if it's not large enough. So you end up with this 30 pound monster which has to be put in a case that has 6 inches of space between the transformer and the side of the transformer case.

Why don't you look at just powering from 240? Many LED dimmers run off it. You can get UK 240v lamp dimmers off ebay for your soldering iron and other purely resistive heaters. They don't care about voltage just power. Many neon power supplies run off 220/240. cordless power tools run off batteries which run off a battery charger that is often dual voltage. And Ebay is flooded with very cheap 220v power tools from China where that's normal power for them.
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Old 03-01-2019, 07:42 AM   #22
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Re: 240/120 stepdown transformer


Sounds like the EV is your get out of jail card. Install as large a sub panel as possible in the garage with an EV branch circuit and receptacle off of it. There’s no need to mention other uses for the panel. If asked just say you prefer a breaker for the EV near the vehicle much like a lot of hot tub sub panels are used.

Once you have the panel in the garage other circuits are easy.





outlet off o


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