Beauty in The Beast: Webb 5BVK Barn Find/Conversion

[Dabbler]

Sorry @Charlieman22 @sdelivery is right on. NEVER mix 3PH and 1ph circuits. In Canada, you are allowed to take a 1ph circuit off a 3PH panel using a 1pole breaker. If you have a 1ph panel you can never have a 3ph breaker in it. Strictly forbidden here, and I'm pretty sure it won't even fit. Get a pony box - a 3 phase box with no main breaker, and run your 3 phase circuit through it, with the correct sized 3ph breaker.

Everything should be done so in 5 years, you or then next owner can easily see what you did. Everything you do should pass code, even if you can skip the inspection.

 

[sdelivery]

The code book or at least some of the tables are available on line.
I would suggest you look at conduit fill, ampacity of wire

 

[Charlieman22]

Gents,
Wouldn’t have posted if I wasn’t looking for critique - looking to learn/ appreciate the responses.

The takeaway is clear - don’t mix 3P and 1p on same breaker.
However - I was confused by some of the feedback and want to clarify.
No discussion = no learning…

In Canada, you are allowed to take a 1ph circuit off a 3PH panel using a 1pole breaker. If you have a 1ph panel you can never have a 3ph breaker in it. Strictly forbidden here,

This is a 3P panel.
Just to clarify - I was asking about running a 3 pole breaker (single breaker, 3 poles) and using 2 legs of that breaker for some receptacles and 3 legs of it for another receptacle.

, you would have 2 breakers so one could trip and one might not.

I couldn’t follow this. There would be a single breaker as per image below. Two legs feeding all receptacles, the third leg feeding only one of them to make it 3 p. Wouldn’t this trip as a single unit? Is this what you understood from my first post?

A dedicated 3 phase circuit with its own 3 phase circuit breaker in its own conduit is proper and current code requirement.
Remember someone else might not realize what you have done and go to work on a circuit and be injured.
I know your excitement to build and try out this new machine BUT stand back and
Double check everything.

I’ll have a look at my panel and reassess how I could create a single 3P circuit for my desired 3P outlets - and keep separate the 1p circuits.

I think I can create a 3 p circuit that feeds the mill and compressor as a stand alone - tho available space in the box is limited…

Thanks for the responses. Much appreciated.
-CM.

 

[Dabbler]

Thank you for clarifying the details.

The concern here is very simple. The current draw to fire the breaker is set for 3 phase, and is not calibrated for the 1 phase draw. It might fire in an overcurrent situation, or it might not. Really you'd have to test it, but I think your decision to go with a dedicated 1ph breaker is for the best.

 

[Charlieman22]

Thanks Dabbler.
Got it.

 

[sdelivery]

Dabbler covered most of what I didn't in my original post other than phases being unbalanced.
You are 100% correct conversations can lead to learning.
I understand copper is very high right now as I have been holding off a new run to my shop because the materials flat out doubled in price...SMH I was looking at 2500.00 for materials and now the best I can do is 4600.00 and climbing as I fail to pull the trigger.
I see a 60 Amp 3 pole breaker, what's your plan?
We're all of your recepticals going to be high current?

 

[sdelivery]

In the US most of the original three phase wiring is 3 hot legs with no neutral as time has passed the newer installations have included neutral and grounds from the feeder transformer.
It is not an accepted practice to have three phase and single phase mixed in one panel.
This comes back to having no neutral connection and the ground absolutely shall never be used as a neutral.
This starts the argument that they are bonded together in the box so it's the same...until a failure causes the ground to become hot or a poor connection fails to return it to the box.

 

[Charlieman22]

My shop is rented, and it came with a single - and fairly small panel.
It’s fed by 3 phase and a neutral.

There are single phase and 3 phase breakers inside the panel box.
Replacing the box may not be viable - owners of the shop space have it as they have it…
I’m not terribly surprised it’s not to code.
Suspect all the connected shops are similar.

It is not an accepted practice to have three phase and single phase mixed in one panel.

Noted - though it appears this is the standard here.

This comes back to having no neutral connection and the ground absolutely shall never be used as a neutral.

Neutral is not used as a ground on any circuit. However, The neutral is only used on the single phase circuits.

My three phase has 3 legs and a ground - the ground going to the box.
Neutral is not used with the 3 phase.

Sounds like the ideal would be a sub panel running all my single phase.
Curious why having single and three phase in a single box (panel) is against regs.

 

[sdelivery]

In most machine tools there is a single phase "control" transformer fed from the three phase incoming power so your neutral would be developed there.
Doesn't sound like your electric is that bad.
But if there is no neutral provided from the supply transformer then you should probably consider a transformer.
Look on the label inside the door of your electric panel. If it is capable of both 3 phase and single phase service there will be a listing of the breakers and accessories.
Keep in mind California has regulations above and beyond what the other states have, so I can be of some help but have never studied California regulations.

 

[extropic]

snip>

Sounds like the ideal would be a sub panel running all my single phase.
Curious why having single and three phase in a single box (panel) is against regs.

Bingo!