Is 1sq mm wire ok for powering a 2.2KW VFD,

[javeria]

Hello All, I was wondering if a 1 sq mm wire would suffice to power a VFD

I was looking at this cable.

[riesvantwisk]

Irfan,

I found this table, it shows the amperage for each AWG number : http://www.powerstream.com/Wire_Size.htm

1mm2 is AWG 17 and according to the chart 19Amps for power transmission

Two problems though:
1) a Spindle operates at different frequencies and as teh frequency change, so act electrons in a cable, they tend to move the the outer layer of a cable...

2) Highly likely, a spindle doesn't operate at a voltage that comes out of your the plug in the wall.

So we missing two constants that are known to know if a AWG 17 cable can run your 2.2K Spindle.

My advice is check the manual of the spindle or call your supplier, or may be somebody else on this forum has the same type of spindle an can tell you :=


Ries

[javeria]

Thanks for the response Reis, my trouble is that my Lapp cable - supplier want's me to buy the whole 100mtrs , so I was planning to use it on all stepper drives and spindle - I know one of the forum members still has a 0.75sq mm on the spindle.

well it would be great if anyone can post link to a calculator or so - I will also ask my delta vfd tech support folks for help.

RGDS
IRfan

[riesvantwisk]

delta vfd would know for sure.. you could always strand 2 wires together, this because the cable has 4 cores.... (not ideal but...)
But if other use even smaller wirs, it from what it looks would be fine...

Ris

[Atifeh]

Irfan,

According to Delta, type E VFD's, the recommended wires for 700W-3.7kW frames is .8-8.4 mm2 (18-8AWG) and for the 5.5-11kW frames is 1.3-8.4 mm2 (16-8 AWG). This variation should reflect that the construction and internal wiring of each frame size differ. As for my experience, I use 3x1.5mm shielded cable for a 2kW spindle and a 2.2kW VFD. It run 4 hours straight and I checked for any temperature on the cable and on the VFD and everything was fine. The total length of the spindle cable is 17 meters.

[KenC]

Ever consider loudspeaker wires? The comes in 12AWG or bigger, they are ment to work high current, broad band width (5hz ~20kHz) and if you are worry about insulation, pull a heat shrink wrap over it, that will be good to 2KV.
They has more strands, 32strands is the minimum that I saw a lot more then any industrial cables hence very soft.

[domino11]

Ken,
I would be surprised if speaker wire would have a conductor to conductor insulation that would withstand 2KV. Speaker wire in the industry is the most over hyped and over marketed product. They also charge you too much. :)

[digger]

Ken,

I would think about cable with shield. Reason for that is: spindle is supplied by VFD with square wave voltage, which is very rich with harmonics. You want to keep them in a cable and not radiate around and have an issues with 'crazy drivers'. One method of keeping radiation inside of the cable is to ground shield and the other one is to use toroidal rings (you may see how they look like on a cable between monitor and computer). Just put a cable through the ring and that's it.

[KenC]

Ken,
I would be surprised if speaker wire would have a conductor to conductor insulation that would withstand 2KV. Speaker wire in the industry is the most over hyped and over marketed product. They also charge you too much. :)

Heath, pardon my English, am aware the cable doesn't have 2KV insulation between conductors. I meant if one is worry that speaker cable not have enough insulation for safety, one can wrap a heat shrink sleeve over it. This sleeve will provide the 2KV insulation.

I agree the loudspeaker cables are overly hyped. Use pro-audio cables, they are safe from hype.

For experiment on my kitchen table project, I bought some no brand OFC cables (in loose quantify) for less the US$1 per meter. i.e. ~30cent/ft. from local pro audio shop. If I need some rope in a hurry, they will come in handy.:D

Ken,

I would think about cable with shield. Reason for that is: spindle is supplied by VFD with square wave voltage, which is very rich with harmonics. You want to keep them in a cable and not radiate around and have an issues with 'crazy drivers'. One method of keeping radiation inside of the cable is to ground shield and the other one is to use toroidal rings (you may see how they look like on a cable between monitor and computer). Just put a cable through the ring and that's it.

Digger, thanks for the tips on the toroidal rings. Are this called "reactors" in the VFD manuals?

I was worried will the cables will be too noisy as well. I'll have a go at them if noise turn out to be a problem.

Regards

Ken

[Besser]

Having your control box attached to the MM saves a lot of cable! then you can run one power and one Data to the control box. You also shorten the antenna effect of the wires. My reading of the VFD manual seems to mention a much larger cable but I have chosen to go with 2.5mm2 cores Cu shielded for a 2.2kW spindle and 10m of length. There is a slight problem with the bend radi being slightly under the manufacturers spec at this stage.

So Keep the run length as short as possible and fit the biggest cable you can (bend radii and cost limited)