Advice for new 240v circuit


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Old 11-16-15, 02:14 PM
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Advice for new 240v circuit

First time poster here. I would like a 240v outlet in my garage. So I'm coming to you guys for the how to on the proper way to do it.

I need a 240v/50amp breaker (not set on 50amps, may go 30), it'll need to be 4 wire, and I need GFCI. The main breaker panel is in my garage on the same wall that I'd like the new outlet. The garage is finished. I have relatively easy access to the attic above this wall. This wall is an exterior wall, but being the garage I'm not sure if it has insulation in it or not, I'll check this evening. I have no problem tearing out some dry wall or running conduit, which ever option is best.

When it comes to what is code or not I don't know.
So, what more information can I provide you? What's the best way to go about getting my 240v outlet?

Also, what about a spa panel?
 
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Old 11-16-15, 02:45 PM
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Welcome to the forums! If you have the space for a double breaker in your panel you can run your 4 wire cable to the receptacle. We'll first need to know what this will be used for. 50 amps would work for a welder or hot tub, but too big for a compressor or other 30 amp or less applications. Once we know what you are doing, we can advise as to the breaker size, wire size, etc.
 
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Old 11-16-15, 03:01 PM
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If the breaker panel in the garage is on the surface of the drywall, find a 3/4 or 1 inch knockout on either side of the breaker panel and attach a electrical box to the breaker panel for the 240 volt receptacle. Wire the receptacle to the breaker.

If the breaker panel is recessed into the drywall, look for a 3/4 or 1 inch knockout on the bottom of the breaker panel. Make a hole in the drywall below the breaker panel for the new electrical box (type that has ears that grab the backside of the drywall as the securing screw is turned). Place the hole so you won't hit a stud. Put a strain relief clamp in the knockout at the bottom of the breaker panel and run the cable before securing the receptacle box. Wire the receptacle to the breaker.
Good luck.
 
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Old 11-16-15, 03:10 PM
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All of the above! This will primarily be for powering a 5500 watt hot water heating element for home brewing equipment. A 50 amp would give me room to add a second smaller wattage element (< 4100 watt) if I decided I wanted one for my brew system, and like you said it would also allow me to use a welder if I decided I wanted to do that too (not *that* likely).

I figure 30 amp can certainly get the job done right now, but 50 amp allows for future upgrade-ability/toys. I figure as long as I'm doing the work I may as well go 50, maybe that's not worth the added expense/trouble?

BTW - it appears that my town uses the 2014 National Electrical Code and the following amendments starting at page 61: http://www.littleelm.org/DocumentCenter/View/7525
 
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Old 11-16-15, 03:25 PM
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it'll need to be 4 wire, and I need GFCI
This will primarily be for powering a 5500 watt hot water heating element for home brewing equipment.
So why do you need 4-wire and why do you need GFCI? A water heating element only needs 240 volts so why do you need a neutral? A water heating element normally doesn't require a GFCI.
 
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Old 11-16-15, 04:39 PM
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In addition, you won't be "stacking" the heaters on the same breaker. Each would require a breaker of its own for overcurrent protection. I would add a subpanel, possibly with individual breaker capacity for each of your anticipated uses and add them as needed. You could run it off a 50 amp breaker in your main panel.
 
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Old 11-16-15, 04:50 PM
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I'm sorry, I should have elaborated before, I will need to the neutral wire for the electronic control panel for the heating element(s) and peripherals. Here is an example of what my control panel might look like to give you a better idea of what's going on: http://www.pjmuth.org/beerstuff/imag...ring-2-4-a.jpg

I took some pictures of my main panel:




 
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Old 11-16-15, 04:59 PM
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@chandler,
I'm using a control panel, essentially a subpanel, to control everything. Within this panel will be the overcurrent protection to the compents in the system. I linked an example control panel in my previous post, however that example has two elements it has a switch to only power one at a time.

Here is a 50amp example: http://www.pjmuth.org/beerstuff/imag...2451-5500w.jpg
 
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Old 11-16-15, 05:38 PM
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So this thread has developed from a simple receptacle to an entire control panel, right?
 
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Old 11-16-15, 05:45 PM
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Oh no, I was just elaborate on what I need my recepticle for. I've got a handle on my control panel. What I need to figure out now is how to properly install a 240v recepticle in my garage.

I suppose I could install the recepticle as beelzebob suggests, right below the main panel, but there isnt a whole lot of space between the panel and the floor. Are there any codes that specify that this 240v reciptlce will have to be x inches off the ground?

Also, I don't know if it matters, my hot water heater is about 2 feet to the left of the main panel... never liked having it that close to the panel, but it is what it is.
 
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Old 11-16-15, 06:01 PM
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my hot water heater
Which raises the question why are you heating hot water.
 
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Old 11-16-15, 06:05 PM
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Lol. Well... that's a topic for another forum!
 
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Old 11-16-15, 06:16 PM
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I'm sorry, I should have elaborated before, I will need to the neutral wire for the electronic control panel for the heating element(s) and peripherals.
Then you don't need a 240 volt circuit and receptacle which is 3-wire, you need a 120/240 volt circuit and receptacle which is 4-wire. GFCI protection isn't required by NEC unless the control panel manufacturer's instructions say it is necessary. I would surface mount conduit from the panel to the control panel and hard wire the control panel. No need for a receptacle or a spa panel here.
 
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Old 11-16-15, 06:28 PM
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Then you don't need a 240 volt circuit and receptacle which is 3-wire, you need a 120/240 volt circuit and receptacle which is 4-wire. GFCI protection isn't required by NEC unless the control panel manufacturer's instructions say it is necessary. I would surface mount conduit from the panel to the control panel and hard wire the control panel. No need for a receptacle or a spa panel here.
I specificy GFCI protection After all, this system will be boiling and pumping liquids around between vessels.

I'd prefer my control panel not be hard wired to my main panel either, I intend on the control panel being mobile/removable.

So what I'm trying to figure out is the proper way to run wire from my main panel to this guy: http://www.theelectricbrewery.com/30...et-NEMA-14-30R

Or, maybe it's cheaper or easier to go the spa panel route since I need gfci?
 
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Old 11-16-15, 06:44 PM
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I specificy GFCI protection After all, this system will be boiling and pumping liquids around between vessels.
Ok, buy a Cutler-Hammer CH series spa panel with factory installed 50A GFCI breaker. You don't need the panel, but buying the 50A GFCI breaker separately will cost more. Rob the breaker from the spa panel and install it in your main panel.

Eaton 50 Amp Type CH Spa Panel-CH50SPA - The Home Depot

I'd prefer my control panel not be hard wired to my main panel either, I intend on the control panel being mobile/removable.
Ok, run surface mounted conduit from the main panel to the control panel location and terminate the conduit in a 2 1/8" deep 1900 box. Install the receptacle in the box with a raised cover. A flush range receptacle would work.

Leviton 50 Amp Nylon Power Single Outlet - Black-R50-00279-000 - The Home Depot

Install a range cord/plug on the control panel.

Whirlpool 4 ft. 4-Wire 50 Amp Range Cord-PT500 - The Home Depot
 
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Old 11-16-15, 06:53 PM
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Ok, buy a Cutler-Hammer CH series spa panel with factory installed 50A GFCI breaker. You don't need the panel, but buying the 50A GFCI breaker separately will cost more. Rob the breaker from the spa panel and install it in your main panel.
So it would be preferable to rob the spa panel of it's breaker rather than just use it as is? It should just fit my panel?

What's the proper methods/materials go from my in wall mounted main panel to surface mounted conduit?

So I can just run the conduit straight down the wall and be done with it, or are there any codes that might come into play here that I need to be aware of? Doesn't have to be a certain height off the ground, or distance from the ceiling, or so many feet from the garage door, etc.

I just found this on a random google image search, should it end up looking like this:
 
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Old 11-17-15, 06:01 AM
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@casualjoe, Sorry, I just noticed you specified CH series spa panel that answers my first question in my last replay.

Still wondering though, what's the proper way to transition from interior wall to surface mounted conduit? Also, any codes I need to be aware of while im making my run?
 
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Old 11-17-15, 08:17 AM
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An offset bend on a 90 would roll you out of the panel and onto the surface. You could mount a 2 gang box under the panel and use cable in the wall to get into the panel. The receptacle could be flush mounted.
 
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Old 11-17-15, 08:48 AM
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PVC or metal conduit?

Also, while I'm at it I should probably run another 120v/20amp circuit in the garage. Can I run this cable through the same conduit?

[Edit] Limited research suggest I could run multiple circuits through one conduit but I'd need to derate them for 5 conductors?
 
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Old 11-17-15, 11:11 AM
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So would it be a bad idea to run romex out of a knock out, fish it a short distance to a surface mounted junction box, and run conduit from there?
 
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Old 11-17-15, 11:24 AM
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Not a bad idea at all, it would be a legal way to handle the situation.
 
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Old 11-17-15, 11:30 AM
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Not a bad idea at all, it would be a legal way to handle the situation.
Does the romex require a strain relief clamp as it exits the main panel? I'm wondering if I'd be allowed to go sideways, through the 2x4, instead of down so close to the floor.

(I just remembered this is what beelzebob suggested at the beginning of this thread)
 
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Old 11-17-15, 12:30 PM
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Yes, it requires a box clamp. There are many different styles including push-ins, friction fit, plastic and metal. You can probably find one that will fit your situation. The clamp part can be inside or outside the panel box.
 
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Old 11-17-15, 12:58 PM
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So it would be permissible for me to pull of a knock out and drill through the 2x4 that's behind it?
 
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Old 11-17-15, 02:13 PM
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Thanks to everyone that's chimed in so far, I think I have a pretty good handle on how I'm going to tackle this.

Now I have another question regarding conduit fill and derating:
I was thinking about pulling 3x 6awg conductors + 2x 12 awg conductors (+ground) through a single conduit. When calculating conduit fill you only consider the CCC correct? By this calculator my plan would have a fill of 35% on 3/4 pvc. Do I need to derate the amperage capacity?

[Edit] I think I figured it out, let me know if I'm wrong.
I'll be using THHN/THWN/THWN-2 wire for the conduit runs. I have 5 conductors so I need reduce the ampacity to 80%. The amperage rating for awg 6 is 65 to 75 amps (depending on temp rating), and for 12 awg is 25 to 30 amps (depending on temp rating). SO, worst case, the derated value of my CCC are 52 amps and 20 amps respectivly, so I shouldn't have to worry about it... Right?

Of course I wont have room to run more wire in this conduit in the future.
 

Last edited by kcd2015; 11-17-15 at 02:29 PM.
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Old 11-17-15, 05:52 PM
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So it would be permissible for me to pull of a knock out and drill through the 2x4 that's behind it?
That would be extremely dfficult, I wouldn't waste my time on it.

So it would be preferable to rob the spa panel of it's breaker rather than just use it as is?
Yes, all you need is the CH series GFCI breaker, you do not need the spa panel enclosure. If you price the 50 amp CH series GFCI breaker at a distributor, I think you'll find it costs more than the spa panel with the GFCI breaker included. The CH series GFCI breaker will fit right in your main panel.
 
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Old 11-17-15, 06:07 PM
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You will need a large hole in the stud to fit the connector in. You are probably looking at 1 1/4" or larger.
 
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Old 11-19-15, 01:45 PM
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Got a quick and easy one for ya

So I'm going to be running #10 for 30amps and #12 for 20amps in a horizontal conduit run down the length of the wall. The 30 amp receptacle at the end, 2 to 3 20amp receptacles along the way.

Do I have to, or is it code, that I use pigtails to connect to my receptacles? Take the attached image for example, could I just bring my incoming wires in from the left directly to a hot screw, do a jumper wire to the other outlet, and use the remaining screw to run the wire out the right to the next box? eliminate the wire nuts and save a little space in the box?

 
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Old 11-19-15, 02:12 PM
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Pigtails are mandatory on grounds -- grounds must be continuous without the device installed. Pigtails are only mandatory on circuit conductors if you are using a multiwire (a.k.a. split wire, shared neutral) circuit. Typical circuits they are optional, with varying degrees of evangelism on either side of the issue.
 
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Old 11-19-15, 03:29 PM
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You will need gfi,protection in the garage on the 120 volt circuits.

It will be easier to run THHN conductors in the conduit vs NM cable.
 
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Old 11-20-15, 07:12 AM
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You will need gfi,protection in the garage on the 120 volt circuits.

It will be easier to run THHN conductors in the conduit vs NM cable.
Both the 120v and the 240v are getting gfi
 
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Old 11-21-15, 06:54 PM
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Using stranded thhn wire. What does the code say about using crimp spade terminals at grounding screws? Is that preferred or frowned upon?
 
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Old 11-21-15, 07:30 PM
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Code is silent concerning the lugs. I always use lugs when dealing with stranded wire but never when using solid wire.
 
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Old 11-22-15, 02:32 AM
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Use pressure plate type receptacles (GFCI's) and you won't have to deal with lugs. I only use lugs where absolutely necessary, and use an exothermic weld crimper to accomplish it rather than pliers.
 
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Old 11-22-15, 08:26 PM
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Use pressure plate type receptacles (GFCI's) and you won't have to deal with lugs. I only use lugs where absolutely necessary, and use an exothermic weld crimper to accomplish it rather than pliers.
I'm installing several receptacles, the first one in the series is gfi but everything after that will be normal 20 amp duplex receptacles. I have a ratcheting crimper, don't know that it will match your welder
 
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Old 11-22-15, 09:28 PM
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Unless you have special equipment you don't need 20 amp receptacles. 15 amp receptacles are code compliant on 20 amp circuits as long as there are two or more places to plug in.
 
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Old 11-23-15, 07:11 AM
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You can get standard duplex receptacle with back wire terminals. They are usually sold as "spec grade", "commercial grade" or similar marketing lingo. These are much higher quality on all the other internal components too.

Code only requires that any spades or lugs you use be UL listed for voltage, wire type and wire size where they are installed; and you install them with the correct tool recommended by the manufacturer (this is the same standard applied to all premises wiring components). Watch out buying these at a hardware store as they are sometimes only automotive grade (12V, finely stranded primary wire). You need one compatible with at least 300V insulation rating and use on copper compact stranded wire. The package will usually declare which type of crimp tool is required.
 
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Old 11-23-15, 08:15 AM
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You can get standard duplex receptacle with back wire terminals. They are usually sold as "spec grade", "commercial grade" or similar marketing lingo. These are much higher quality on all the other internal components too.
I'll have to take a closer look, I had asked because the receptacles I saw with back wire terminals I saw at the hardware store still just had a screw for the ground.


you install them with the correct tool recommended by the manufacturer... The package will usually declare which type of crimp tool is required
Interesting, I figured as long as I matched up the color codes these would get the job done for any (insulated) crimp terminal. I looked at the packaging for the 10-12awg (yellow) terminals I have on hand, the don't mention what type of tool to use. I'll spec that out.

Titan 11477 Ratcheting Wire Terminal Crimper - - Amazon.com

Been using these for a year now, pretty happy with them.
 
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Old 11-23-15, 08:42 AM
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The other very handy option is these: Ideal Industries - Term-A-Nut Twist-on Pigtail Wire Connector

Especially the green ones for metal box grounding.
 
 

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