Why did electrician use this wire?

[Shaun @ Tru6]

10 years ago I had an electrician wire in a silk screen oven. The oven was right next to the fuse box so they just took the wiring from the HVAC system and ran it down to a box a few feet from the breakers. Then ran this wire in metal conduit that ran up to a box mounted on the oven frame and then some flexible conduit to the control box.

They used this 1/4 inch thick twisted wire. Why did they use this vs. solid wire?

The powder coating oven I'm building is about 20 feet away from this box on the wall. I thought the easiest thing to do would be to buy or make an extension cord between the two.

Thoughts?

Box as the electrician wired it from the fuse box



Control box



Control box with wires from the box and a ground



Close up of wiring I pulled out of the metal conduit



Wiring



Box on wall now. Breaker is turned off of course. I plan on putting an outlet here and one on the side of the control box that will be mounted to the oven and I can run a ground to the oven.

[wdfifteen]

Nothing wrong with stranded wire. It's more flexible and easier to pull through conduit.

[Shaun @ Tru6]

OK, good to know, thanks. Now I just have to figure out how to wire in the outlets.

[dad911]

you have 220 or 3 phase? We can help if you show pic of the wire at breaker, or comfotable measuring voltages. Also, there is a size on wire, a number after the letters AWG

[craigster59]

Look on the bright side Shaun. When working with electrical you usually know right away if you've screwed up!

J/K, Green wire (even the black wrapped with green tape )is ground), white neutral and red and black are your 110v hots. C'mon, give it a shot!

[Noah930]

^^^Listen to Craig. What's the worst that could happen?

[rwest]

When I wired a 30 amp circuit, the home center only had 10 gauge in stranded. Probably because of the pulling issue; solid could be a bear.

[Shaun @ Tru6]

Originally Posted by dad911

you have 220 or 3 phase? We can help if you show pic of the wire at breaker, or comfotable measuring voltages. Also, there is a size on wire, a number after the letters AWG

thanks, I'm pretty sure this is 3 phase. I can check at lunch. wire size too.

I changed a main breaker on the outside of the building without having the power turned off so I'm pretty comfortable measuring voltages.

[sammyg2]

220, 221 .... whatever it takes.

[asphaltgambler]

If I'm not mistaken stranded wire of same gauge carries same current at lesser resistance................

[bpu699]

You shouldn't have anything running off the same breaker as your HVAC. That's against code. You could trip the breaker and lose heat in the winter...

Make sure that's ok. Perhaps I misunderstood.

[rick-l]

Originally Posted by asphaltgambler

If I'm not mistaken stranded wire of same gauge carries same current at lesser resistance................

No The wire gauge specifies the cross sectional area.

Stranded wire is more flexible than solid and won't work harden and break in a flexible conduit.

[Shaun @ Tru6]

Originally Posted by bpu699

You shouldn't have anything running off the same breaker as your HVAC. That's against code. You could trip the breaker and lose heat in the winter...

Make sure that's ok. Perhaps I misunderstood.

HVAC is completely disconnected. Only the silk screen dryer ran off this breaker for 10 years. I repurposed the heating elements and controller from the dryer to the oven.

[Shaun @ Tru6]

Voltage Readings

G-R = 121

G-B = 121

G-W = .X

R-B = 211

W-R = 121

W-B = 121

[tadd]

Shaun:
Is this an office building or a home?
Three phase is ultra unusual in a home. About the only place you can find it 'homestyle' is on a farm.

[Shaun @ Tru6]

Office Tadd. Have about 4000 sqft of space.

[1990C4S]

That is a normal 240 volt supply.

240 between phases (R-B)

120 from each phase to neutral (R-W and B-W)

0 volts between neutral and ground (W-G).

[Shaun @ Tru6]

So the outlet would be wired like this. Clearly green is grounded to the box. White is T2. I'll have to double check but I think T1 is black and T3 is red but it probably doesn't matter.

Is that correct?

[Mark Henry]

Single phase.
Likely the controls run off of one 120v leg thus the white neutral wire, the elements themselves run 220v and use the red/black and green (ground) wire.
Looks like 10 or 8 gauge wire, you might be able to read numbers on the wires.
what size is the breaker?

[Shaun @ Tru6]

Wire is 4 gauge. Breaker is 100 amp.

Hoping to have it wired up and working over the weekend though I still have to figure out where to put the thermostat probe. Then I can skin the inside and get some work done.