Difference between flexible 3 wire (6/3) and 4 wire (6/4) for 50A panel

[brewguyver]

Hi All,

I'm trying to figure out whether I need 3 or 4 wire flexible cable to go from a 50A spa panel to my new din rail breaker box. I'm only using 30A right now, but i want to get the right wires to support 50A as I expand it.

I want to make sure that the wiring I chose supports that effort, is grounded, and supports 4 wire twist lock connectors.

The best site I've seen is here: http://www.wireandcabletogo.com/SOOW-All/. Based on their product list, 6/3 supports 55A, 6/4 supports 45A (too small) and 4/4 supports 60A. Do i need 4 wire (and 4/4) or is 3 wire fine?

Side note - I was going to use ebrewsupply for their 6/4, but it only comes in pre-cut 10' lengths.

 

[milldoggy]

6/3 is 3 conductors and a ground, that is what you need.

Edit, I was wrong then, guess that is just for romex

 

[GotPushrods]

When it comes to service cable, 6/3 will mean 3 conductors. It is named like a normal sane person would name it.

If it were Romex, the ridiculous guessing game would ensue, but more rational minds named regular cord. If you are going with 6 AWG, you want 6/4.

 

[raouliii]

I believe that the labelling of SO and SJO cord is such that the labelled number of conductors includes the grounding (green) conductor.

The OP's link clearly indicates that the #/3 cord has three conductors, white, black and green; the #/4 cord has four conductors, white, black, red, and green.

Therefore, if the OP's panel requires 240 and 120 then #/4 is needed. The ampacity rating of the linked 6/4 SOOW is 45A and 4/4 SOOW is 60A.

FWIW, for SO/SJO cord and NM (romex) wire, the labelled number of conductors is equal to the number of individually insulated conductors. When NM wire has an extra bare copper conductor it is labeled as "with ground".

 

[Brumateur]

4 wires cord rated 45 Amp in assumption that all wires carry a full load. In your case only 2 wires will carry a load - two hots, neutral will be laded very insignificantly. So fill fre to use 6/4 cord.

 

[brewguyver]

Thanks all - i figured that was the case but sometimes I overdo things out of paranoia.

Someone pointed out both the 6/4 and 4/4 cables from that site are non UL listed. Would you all agree that's an issue?

As an aside, eBrewSupply got back to me - the 10' lengths issue is a typo, so I can use their product. More costly but probably safer.

 

[sandyeggoxj]

I power my 50 amp panel with 6/4 soow cord. The high load appliances running fully on 2 wires. The ground shouldn't be used... and of course, like other posters mentioned, the neutral should only have a few amps for pump, controllers and such.

Brew on!

 

[BlkWater_brewer]

I decided to configure my panel to use a 50A RV cable. Mainly because I had easy access to them. It's overkill but.... A few times a year my brew club goes camping and I didn't want to be left out. Campsite with hookup and mobile e-brewery with the correct plug already configured. less work than filing and lugging propane tanks.

BTW - I did utilize the 4th wire as a true ground wire. The panel end is attached to grounded copper post and I have battery charger clips at the control panel end for a physical ground to the kettles and RIMS tube. It was there figured I'd use it.

 

[spkguitar]

I only needed a very short run of 6/4 myself, so I ended up buying a 6ft, 4 prong dryer cord on ebay and cutting the plug off. It ended up being perfect for what I needed and clocked in at about $2.25 per foot (after shipping). Cheaper than most everything else I found, including eBrewsupply (which I completely support and used for a lot of the other components).

 

[trimixdiver1]

I only needed a very short run of 6/4 myself, so I ended up buying a 6ft, 4 prong dryer cord on ebay and cutting the plug off. It ended up being perfect for what I needed and clocked in at about $2.25 per foot (after shipping). Cheaper than most everything else I found, including eBrewsupply (which I completely support and used for a lot of the other components).

Is the cord rated for that?? If it had a molded on plug then it's an improper use. Cable assemblies are rated as a complete assembly and may not be UL rated once cut off. Is the cable clamp correct for it? You need to make sure everything you do with electrical is rated and approved for that use. Otherwise if you hurt yourself or someone or burn your house down, it's all on you.

There are reasons why SO cable costs more, it's rated for the type of service you are using it for, appliance cables are for their own purpose. Do it right or don't do it.

 

[spkguitar]

Cable assemblies are rated as a complete assembly and may not be UL rated once cut off.

Is *anything* we're doing as DIYers UL rated?

The cable I purchased was rated 50A. That was all I personally was concerned with. If I wired the original 50A cable to my control panel, then plugged it into a receptacle wired to my 50A spa panel? Same? Different? How? Educate me; I admit I'm ignorant.

You need to make sure everything you do with electrical is rated and approved for that use. Otherwise if you hurt yourself or someone or burn your house down, it's all on you.

Again, as DIYers, I was assuming that was the risk that we are all taking.

Unless you know of an affordable plug-and-play, UL rated, system for purchase?

Do you have DIY plans for people to follow? Kits? Might make a great addition to the store.

Do it right or don't do it.

I honestly think that advice applies to quite a number of people on here, vendors included.

 

[trimixdiver1]

Is *anything* we're doing as DIYers UL rated?



The cable I purchased was rated 50A. That was all I personally was concerned with. If I wired the original 50A cable to my control panel, then plugged it into a receptacle wired to my 50A spa panel? Same? Different? How? Educate me; I admit I'm ignorant.



Again, as DIYers, I was assuming that was the risk that we are all taking.



Unless you know of an affordable plug-and-play, UL rated, system for purchase?



Do you have DIY plans for people to follow? Kits? Might make a great addition to the store.



I honestly think that advice applies to quite a number of people on here, vendors included.

It's you duty to do it right, if not for you then for others safety. I'm talking about UL rated components, not a system and approved wiring methods to maintain the rating, thus safety. DIY is not an excuse for ignorance. Would you feel safe wiring your house or better yet someone else's house? If the answer is no then do everyone a favor and don't play with something you don't understand.

I've seen many DIY jobs, and I've seen several deaths related to those. Most of the time not killing the DIYer but an innocent.

Do it right or don't do it. There are no excuses.

 

[spkguitar]

Would you feel safe wiring your house or better yet someone else's house? If the answer is no then do everyone a favor and don't play with something you don't understand.

The answer is yes, actually.

I also feel very safe and comfortable with my current e-brew rig, for me, my house and my family.

 

[brewguyver]

Was looking at the 30 and 50A Home Depot cables yesterday. Have molded plug on one end, all connectors have spade terminals on the other. They're rated for range or dryer but unadulterated could probably be used for anything of the equivalent load.

 

[Bobby_M]

Keep in mind that SOW cable is rated for 600v and is overkill. Stick with SJOOW which has thinner insulation because it's rated for 300v. If you need to derive a 120 volt circuit in your panel, you'll need 6/4 to the panel. The wire to each element only needs to be 10/3 since it's only 240v with no neutral.

 

[brewguyver]

Keep in mind that SOW cable is rated for 600v and is overkill. Stick with SJOOW which has thinner insulation because it's rated for 300v. If you need to derive a 120 volt circuit in your panel, you'll need 6/4 to the panel. The wire to each element only needs to be 10/3 since it's only 240v with no neutral.

Bobby - any issues using 8/4 wire to elements and just not using one wire? I got a good deal but 20' min on the 8/4 - I figured I could cut it into 5' sections and use it for elements if I ever jump to 50A 4 element setup (which would require a thicker wire to the panel).

 

[Bobby_M]

Only issue is that it's super heavy and bulky to work with.

 

[brewguyver]

Yea - you're not kidding. Thankfully I'm done wiring the spa panel now. I also replaced my 3 wire dryer outlet with a 4 wire job (and the dryer plug). Not sure why I thought clipping the ground was a good idea when I installed it ... but I was a younger (less paranoid) man then.

 

[brewguyver]

Uber diesel.

View attachment ImageUploadedByHome Brew1419487046.014209.jpgView attachment ImageUploadedByHome Brew1419487084.486329.jpg

 

[Brettomomyces]

That's a beefy cord, what is the brown packing around the wires? I haven't cut anything open more than 10/4

 

[The10mmKid]

That's a beefy cord, what is the brown packing around the wires? I haven't cut anything open more than 10/4

That is the 'strain relieving' cord. This one resembles rope. It is common with mobile cords. Keeps the copper wires safe while you drag the cable along the ground . . . . . like an ape.

The lighter versions will use nylon strands.

'da Kid

 

[brewguyver]

It's got nylon strands wrapping horizontally around everything too - just in case there wasn't enough stuff in there already .