Hi

In my industrial building, there is a cable with this written on it
450/750v v-90 <wk 19> L 2005
currently supplies power from a sub-panel to a 3 phase power point which is not being used at all.

I am planing to use this cable as a feeder (bypassing the breaker) to power a showroom which is wall to wall with the industrial building, the show room needs a single phase.

The cable has 5 wires, the red wire "which I am planing to use" has 7 strands of 22 AWG.
How much amps will be the maximum this wire can safely handle?

Thanks

 

My opinion is that if you have to ask here you shouldn't touch the circuit.

 

10 awg is 30 amperes
12 awg is 20 amperes
14 awg is 15 amperes
16 awg is 10 amperes
18 awg is 7 amperes
20 awg is 5 amperes
22 awg is 3 amperes
24 awg is 2 amperes
26 awg is 1 ampere
28 awg is 0.8 ampere
30 awg is 0.5 ampere

 

AWG 22 wire has a diameter of 0.0253" so use a wire gauge chart and either work out or find the cross sectional area for a single strand and multiply times 7 but nothing you typed makes sense. Three Phase WYE or Delta? In the case of WYE phase voltage to neutral? IN the case of Delta you need to run phase to phase. I have to agree you seem to be in this over your head. Any building should have drawings of every distribution bus from a sub and in detail. This should have been done when the bus work went in. The building I worked in had all the drawings from the mid 1960s when the initial bus work went in. When you need to ask the sort of questions you are asking it is apparent you need some good quality help.

Ron

 

It is 40 years old building, No drawing is available.
With the help of online articles, videos, you, and my trade of an auto electrician, I am checking the boxes and making my own drawing.

it is the power supplied by the power company, I would not know how to find out if it is a start or delta, not sure if that is important since each is 240v and I want one phase in the show room, i.e. any one would do.

I figured (adding up all the future potential loads) a total of 5000 watts would be enough to calculate the feeder wire to the main switch of the 2nd sub-panel and the breaker in the 1st sub-panel (can I have a breaker in the 1st sub-panel to protect the feeder going to the switch of the 2nd sub-panel?).

That feeder wire and its breaker in the 1st sub-panel is the main reason for my question.

Thanks again.

 

What is the breaker current?

Ron

 

What is the breaker current?

Ron

The main board has the breaker for the 1st sub-panel, the breaker current is 40A. The wire from the main panel to the 1st sub-panel is 7 strands 19 SWG each, i.e. 5.67 mm square is the total area of this copper wire with 240v. which can handle 50A

The cable I mentioned in the first post I will not be able to use as it operates other devices, so now the plan has to change.
I need to feed the main switch of the 2nd sub-panel, my options;

1. piggyback the wire "mentioned above" before the 1st sub-panel main switch.
   
2. install a breaker in the 1st sub-panel, what amp, 35A OK?

What do you suggest?

 

What do you suggest?

Hire an electrician or make sure the property insurance is paid.

 

Before you piggyback anything you may want to see or read the code for wherever you are. In the US I would suggest investing in a current version of the NEC book and yes, it is costly. Next if you want or need to add a branch circuit (add a breaker) I suggest you look at wire gauge ampacity charts and match the breaker and wire gauge accordingly. There are reasons for code and following codes.

Ron

 

any wiring should be sourced from a breaker, sized to protect the wire. Best is to call an Electrician in. Call a couple and get quotes. Accessing the code book will do you little good unless you are trained in deciphering it, as there are many variables.

 

samjesse you have absolutely no business working on this system.
Please stop... You are not qualified and seeking help via the internet is not a smart move either as we can only give you information on the questions you ask..
We are not there to give you information on the questions you don't know to ask.. <-- thats where the dangers will really come from. The devil is in the details..

The only thing they should do is hire a licensed/qualified electrician.. NOTHING else..

You trying to save money could cause a fire or get someone hurt/killed.. Not smart..