Hi all

Currently installing a machine and need to know the cable weight required.

400v supply from a generator
Machine has total of 50 kw of motors on it.
The distance between the machine and power source is 35meters.

How do I calculate the cable size required?
I think it's 35mm squared cable. Am I right?
Thanks

 

Do you mean cable or wire size? And it could depend on physical lay-out. What is the normal temp in that 35 meters?

Are you sure of that 400V figure? AC generator?

 

Or do you mean the actual physical weight........as for stringing on poles?

 

Basically looking for the wire size of each core.
Working in 20 degrees Celsius all the time .
Thanks

Do you mean cable or wire size? And it could depend on physical lay-out. What is the normal temp in that 35 meters?

Are you sure of that 400V figure? AC generator?

 

I suggest you google "conductor vs current" and look at some wire charts in your language. It will be a large size. Don't forget to look at and figure out the voltage drop for 35 meters.

You might need to buy larger size than you realize.

 

I can see #1.0 AWG for motor loads, is this above or underground?
43mm2 to 33mm2.
Max.

 

How many actual motors, can they be started in sequence or at random?
Max.

 

400v supply from a generator
Machine has total of 50 kw of motors on it.
The distance between the machine and power source is 35meters.

That's 125 amps...

How do I calculate the cable size required?

We call it gauge, not weight.

For power distribution, I'd use 0 AWG.

 

How many actual motors, can they be started in sequence or at random?
Max.

There is 2 motors started one after another in sequence. One starts on star delta and the second one starts after

 

That's 125 amps...
We call it gauge, not weight.

For power distribution, I'd use 0 AWG.

Perfect Thanks. Some people call it weight here in Ireland

 

Um... why are you working with HV and extremely high power when you don't even know how to figure out the required wire gauge? You could easily be killed by a shock or arc blast.

 

Cable with a cross sectional area of 35mm˄2 (1 AWG) is adequate for a current of up to 125A.

Given the cable length, and allowing a load margin you might consider 50mm˄2 (0 AWG) cable which can handle up to 160A.

 

Um... why are you working with HV and extremely high power when you don't even know how to figure out the required wire gauge? You could easily be killed by a shock or arc blast.

I don't do the wiring. I sold the machine. I just have to supply a power cable with it and want to know which one to buy. An electrician installs it.
I'm usually working with single phase and 12v.

 

I don't do the wiring. I sold the machine. I just have to supply a power cable with it and want to know which one to buy. An electrician installs it.
I'm usually working with single phase and 12v.

Oh, ok.

 

Intended to be fed via conduit? Underground? Above ground?
Max.

 

Intended to be fed via conduit? Underground? Above ground?
Max.

Overground. Mounted on wall brackets. Open to the air I suppose.

 

Also make sure there is good, thick, durable insulation. You don't want to go too cheap and have an arc blast or short. You will also need a lot thicker than you may think to have a safe margin. If there are any really HV transients, an arc could be established and maintained with the normal voltage. Even with good snubbers, there is always the chance a HVAC motor will create huge voltage spikes.

 

Overground. Mounted on wall brackets. Open to the air I suppose.

What about all the termination enclosures etc?
Max.

 

What about all the termination enclosures etc?
Max.

On one end cable goes straight to generator poles.
On The other end the cable goes straight onto the main isolator switch in the machine panel. Enters the panel through a grommet and is bolted onto the isolator bars for each phase. Fused after the isolator.

 

If you have an electrician installing this I would have thought he could have spec'd in the cable?
Simple grommet for 400v cable?
It has been many decades since I did this kind of work in the U.K. but things must have changed.
Max.