Can I wire an ev charger to existing electric brewery?

[lupulinaddict]

A quick search I found someone asked about using a 30 amp receptacle and plugging each in when in use. I could do that, but have read the plugs and receptacles need to be replaced every so often. I don’t have the room to run another line, and upgrading to a larger service is still a ways down the road for us.

Question….

How can I use the 50 amp breaker I installed for the brewery to also charge a future ev?

Can I disconnect my brewery’s spa panel and install a 50 amp sub panel to the homes 50 amp breaker? Then install two 50 amp breakers in the sub panel to wire the spa panel, and then hardwire an ev charger?

Obviously, I won’t be using both at the same time. I know this isn’t the proper way, but is this a reasonable way to do this? Other ideas?

 

[tracer bullet]

I know this isn’t the proper way

Well...

I'll only suggest to do it the right way. Don't be the person that inadvertently burns their house down because they were pretty sure it was OK. I'm not saying you have to hire an electrician, but if you already know something isn't right, maybe rethink it.

Where's the main panel, sub / spa panel(s), and the brewery? That might be a factor.

 

[lupulinaddict]

Thank you for the response and warning.

Main panel is on the side of the house. Everything else is in the attached garage, about 50’-75’ away. I ran wire to match the breaker when I did it, it has been awhile so I would need to check, but I want to say it was 6 gauge? The spa panel is mounted inside a cabinet 9’ off the ground. This is only for my use, I mounted this way to keep out kids/friends. Brewery panel is lower with key switch and e-stop within reach. The charger would be mounted on the adjacent wall, but at the correct height, 10 feet away. I’d like to put the sub panel in the same spot as the spa panel. That way I’m the only one who will be able to switch off the charger’s breaker and switch on the brewery’s breaker when I brew.

 

[mashdar]

The NEC allows for installation of "noncoincident loads" and only counting the larger.

But TBH it's a lot more foolproof to just plug/unplug.

The failure mechanism for receptacles is the "retention strength", ie they get loose. When it gets loose after years of use just swap it out.

I've never heard of a plug wearing out unless it's used to repeatedly break load. Don't unplug stuff that's drawing significant amps (general advice).

The cables on the plugs have a wear life, but if you're gentle they should last a long time. Have you ever had a line voltage cord fail without some physical abuse? (Typical culprits are yanking cord to unplug, walking on, power tools, pulling around corners, kinking, etc.)

IMO rdwhahb if the one receptacle is in a good location for both uses. Unless you've got cash to burn and want a cool project, then game on?

 

[sibelman]

fwiw, I swap power to my HLT and kettle with L6-30 connectors. The receptacle sees three connections/disconnections per brew, and lasted well over 100 batches before apparently needing replacement (felt somewhat warm). The plugs can be burnished to restore conductivity, but not the recordable. The L6-30R might have lasted longer if I had bought @Bobby_M 's conductive paste from brewhardware.com sooner!

Not relevant, but... my EV charger is hard wired on its own circuit.

Best of luck, @lupulinaddict , whichever way you decide to go.

 

[M54B25]

Don't unplug stuff that's drawing significant amps (general advice).

Respectfully, doesn't this contradict the advice in the rest of your post to go with a plug/unplug route? Or are you saying unplugging/re-plugging is probably fine if not done too frequently?

It jumps out to me because there are definitely some horror stories out there of fried receptacles due to bad contact with the plug, to the point that many folks recommend hardwiring EVSEs/chargers. I wouldn't personally go that far, but I do think extra diligence is warranted for EVSEs. Gently unplugging once or twice a month would probably be fine for years(?), but more often than that would raise an eyebrow for me. It seems the higher amperage plugs aren't designed with the expectation of frequent plug/unplug cycles (what do you mean you're not taking your welder/brewery on vacation with you?). You also don't want to accidentally unplug a live 10kW connection if you forget the car is actively charging.

Plug wear-and-tear is a big deal because EVs are one of the few "consumer appliances" that can max out a circuit continuously. The Ford Lightning would pull 40amps straight for over 10 hrs if it's doing a 0-100% charge and a more mainstream VW ID4 would be over 6hrs, so plenty of time to make a loose connection hot. (Realistically you'll never actually charge from 0-100 but the point remains.)

Even our brewing rigs pale in comparison to the constant power draw since boils don't require full power and ramping up to mash or boil is usually shorter than an hour.

Obviously, I won’t be using both at the same time. I know this isn’t the proper way, but is this a reasonable way to do this? Other ideas?

I would encourage you to double check the "this isn't the proper way" statement there; it seems the NEC allows it and they're the experts. I am not an electrician but it seems reasonable to me. In a scenario of "non-coincidental" loads ultimately going back to a single breaker, that breaker *should* trip if you accidentally overlap the loads. On the other hand, the failure path for a worn out plug is the receptacle/plug melting or catching on fire; there's no safety mechanism to alert you or stop something from failing further.

To your "other ideas" question: there are options to ensure you can't overlap the loads on a single circuit. Dryerbuddy is a "smart" device that can do it automatically and I think there might be physical transfer switches you could use to ensure you don't accidentally activate both simultaneously.

Lastly: people tend to overestimate the charge capacity they need for their car. Maybe you've already done the math and know you need 40amps to recharge for your scenario which is fine, but if you haven't, don't discount slower speeds. If your car is parked for 80+ hours a week at your house, even on 120v 12amp outlet, that's 300+ miles of charge for an average EV (or 200+ for an F150 Lightning) per week. Just something to consider if you already have a convenient 120v outlet that you can dedicate to EV charging where you park.

Disclaimer: I am not an electrician. Consider this free opinion to be worth what you paid for it.

 

[lupulinaddict]

I guess what I meant by “isn’t the proper way,” would be that each appliance should be on its own breaker. The panel idea could be used improperly by both breakers in the on position. The receptacle can only have one appliance.

Thanks for the advice on charging. I’m not sure which route we are going. I need to replace my pickup and the ev rebates are hard to ignore. The lightning would be an ideal fit, but can’t justify the cost. Recharging from the daily drive could almost be done on 120v. I’d like to have the level 2 charger at home to be able to get it all done off peak.

 

[Airborneguy]

As an aside, I wouldn’t rely on 120v even if I worked exclusively from home. The added peace of mind of 240v is well worth the expense.

 

[sibelman]

Gently unplugging once or twice a month would probably be fine for years(?), but more often than that would raise an eyebrow for me

I think the key thing is to plug/unplug when there's no charging or brewing happening, to avoid arcing. That said, these plugs&outlets may suffer wear and tear even if one is "gentle" (physically and electrically).

 

[mashdar]

Respectfully, doesn't this contradict the advice in the rest of your post to go with a plug/unplug route? Or are you saying unplugging/re-plugging is probably fine if not done too frequently?

It jumps out to me because there are definitely some horror stories out there of fried receptacles due to bad contact with the plug, to the point that many folks recommend hardwiring EVSEs/chargers. I wouldn't personally go that far, but I do think extra diligence is warranted for EVSEs. Gently unplugging once or twice a month would probably be fine for years(?), but more often than that would raise an eyebrow for me.

The idea is to disable loads prior to unplugging. Eg an EV likely has an interlock at the vehicle port to prevent load break scenarios. You should strive to never use receptacles for load breaking except in emergencies. It's a bigger deal if you're drawing 40A, but even a hair dryer etc is going to arc if you unplug it while live.

Re the plug, it is just a static chunk of metal. Unplugging high-current loads causes arcing, which can melt or vaporize some of the plug. Otherwise, as long as it's not corroding, there's not much to go wrong. Almost any contact issue on a clean plug will be due to the receptacle, not the plug. And I suspect most failures in the field are likely improperly torqued wire terminations rather than receptacle wear. If you can't get electricians to use a dang torque wrench, good luck with homeowners.

But, absolutely, a poor connection can be dangerous. And 14-50R are definitely not built for the same number of cycles as 5-15R are. But if he's brewing once a week, that's around 100 cycles a year. I think even a cheap receptacle should last a few years? Personally I'd stick with Hubbell, and I'd bet they'd last a decade.

I suppose you could put in side-by-side receptacles in, it's just less fool proof operationally.

 

[M54B25]

First, let me preface my response by saying I think you'll be good with whatever system you go with because you're clearly thinking about doing this in a smart way. I'm belaboring the point in the rest of my post mostly in case someone else reads this and haphazardly implements what they think is a similar setup but they do it poorly.

I guess what I meant by “isn’t the proper way,” would be that each appliance should be on its own breaker. The panel idea could be used improperly by both breakers in the on position. The receptacle can only have one appliance.

Yes, I get this, and what I'm trying to highlight is that this exact scenario does seem to be allowed by the NEC* because each appliance does have its own breaker. Additionally the sub-panel is protected from overlapping loads by the breaker in the main panel.(2)

For contrast, the plug/unplug scenario does a more effective job of ensuring you only use one load at a time but it has the downsides of:
1) Additional plug/receptacle wear-and-tear on a high power connection point
2) Nothing is systemically stopping you from unplugging a 14-50 plug that is actively drawing 40 amps. Any argument along the lines of "I'll always check/remember..." would apply to keeping the two circuit breakers in your subpanel in opposite positions.

I think the key thing is to plug/unplug when there's no charging or brewing happening, to avoid arcing. That said, these plugs&outlets may suffer wear and tear even if one is "gentle" (physically and electrically).

The idea is to disable loads prior to unplugging. Eg an EV likely has an interlock at the vehicle port to prevent load break scenarios.

Agreed, and agreed. The J1772 plug that connects to the car does have an interlock to ensure you're not unplugging and active load. The 14-50P on the end of the EVSE does not have an interlock, so any prevention of unplugging an active load boils down to a human assessing the situation and behaving accordingly.


*Again, I am not an electrician. My knowledge comes from looking into this topic extensively both from an EV and Electric Brewery perspective and found this exact nuance to be interesting.

(2)Bonus point, since you mention off-peak charging: this would be an additional reason to think you're safe from overlapping the loads if you only charge from midnight to 6am and know you never brew during those hours.

 

[mac_1103]

I'm not an electrician either, but how about an A/B toggle switch? Like this maybe?

 

[mashdar]

I'm not an electrician either, but how about an A/B toggle switch? Like this maybe?

I almost suggested a 60A double throw 2-pole safety switch, but the first result on google was $1,100.

That toggle switch might be a good option for a 30A circuit. The off position is a nice touch, and it's motor rated.

A pair of 60A toggle switches would be a budget option for 50A circuits. Still pricey, though, at ~$150 ea. Might as well put in the spa panel at that point.

 

[Bobby_M]

A pair of 50a two pole contactors in a box with a three position selector switch couldn't be more than $100 to bang up.

 

[lupulinaddict]

A pair of 50a two pole contactors in a box with a three position selector switch couldn't be more than $100 to bang up.

I was thinking of this today. My brew panel can run the boil and hlt, but I remember reading about the boxes that would switch between boil and hlt. Seems like a similar application. It crossed my mind to integrate the switch into the brew panel, but I think I’d prefer them to be separated in the future.

 

[Bobby_M]

I was thinking of this today. My brew panel can run the boil and hlt, but I remember reading about the boxes that would switch between boil and hlt. Seems like a similar application. It crossed my mind to integrate the switch into the brew panel, but I think I’d prefer them to be separated in the future.

If the selection is isolated to the brewing process, there's no advantage to moving the selection outside of the brew panel unless there's not enough room in the box.

On the selection between EV outlet and Brewing panel, you may even be able to jam the two contactors into the spa panel.

 

[sibelman]

If only there were a higher current version of the switch-plus-contactors device I see on Kal's site.

 

[Bobby_M]

If only there were a higher current version of the switch-plus-contactors device I see on Kal's site.

I was going to say they don't exist but then I did come across this (note I can't vouch for it but it's rated at 63amps).

To do it more traditionally/commercial controls like...:

You just need two of these:

And one of these:

 

[sibelman]

more traditionally

Thanks for the ideas, Bobby -- much appreciated. There are even panel-mountable high-current "changeover" switches:

A changeover switch seems a lot simpler than a pair of contactors controlled by a separate switch. Of course, switching under load (due to occasional user error) would cause arcing that would eventually destroy the changeover switch. So I wonder: would contactors survive occasional mistakes better? Are there other advantages to the "traditional/commercial" method?

 

[doug293cz]

If only there were a higher current version of the switch-plus-contactors device I see on Kal's site.

The linked switch does not have integrated contactors. Reading the description, it is just a "standard" 10A, SPDT, center off switch. The description incorrectly refers to contact pairs as contactors.

Brew on

 

[Bobby_M]

Thanks for the ideas, Bobby -- much appreciated. There are even panel-mountable high-current "changeover" switches:
View attachment 827699
A changeover switch seems a lot simpler than a pair of contactors controlled by a separate switch. Of course, switching under load (due to occasional user error) would cause arcing that would eventually destroy the changeover switch. So I wonder: would contactors survive occasional mistakes better? Are there other advantages to the "traditional/commercial" method?

I don't have any reason to believe a switch rated for 63amps would wear out due to switching under load. That's what switches are designed to do. I have a feeling that contactors just have more robust contacts that will last at their rated current.

 

[khannon]

As an aside, I wouldn’t rely on 120v even if I worked exclusively from home. The added peace of mind of 240v is well worth the expense.

And better, 240 works much faster..

 

[Airborneguy]

And better, 240 works much faster..

Exactly. The faster charging speed is what I was referring to. For those who don’t know, you’re talking more than 10x faster from 1-3 miles per hour to about 30-35.

 

[mashdar]

I don't have any reason to believe a switch rated for 63amps would wear out due to switching under load. That's what switches are designed to do. I have a feeling that contactors just have more robust contacts that will last at their rated current.

I'm not an expert, but I suspect it depends on the switch design. The nominal switch rating may not be for load make/break.

E.g. safety switches make/break at one location and hold contact at a different location, so any wear occurs away from the static contact surfaces. I think motor rated toggles may also do that, but I'm not sure. (edit: Safety switches might not technically be knife switches?)

I could imagine a cheap switch that's not rated for make/break, but IDK.

 

[sibelman]

cheap switch

I ordered a cheap "changeover" switch, and will continue my practice of making changes only when there's no load - except when I forget, which is quite rare. Still will be un/plugging my kettle element for cleaning as its cord is captive.

 

[bruce_the_loon]

Hugs his "All sockets must be switched" regulation requirement. Interlocked IEC sockets FTW. Can't switch on without a plug in it, can't unplug when switched on.