400 Hz drop down cable

[PowerdT]

I couldn't find anything in NEC book about 400Hz. I was hoping if anyone knows what manufacture provides 400Hz cord reel or if anyone came across to install 400Hz cord reel to the ceiling to share experience?

Thank you.

 

[LarryFine]

I don't think cord reels have a frequency rating.

 

[PowerdT]

I don't think cord reels have a frequency rating.

I see. So can I use a standard cord reel for 400Hz conductor in aluminum raceway?

 

[LarryFine]

So far, frequency is not relevant to your question.

But, why would a cord-reel cord be in a raceway?

 

[PowerdT]

So far, frequency is not relevant to your question.

But, why would a cord-reel cord be in a raceway?

Sorry for confusion. I meant 115Vac, 30A, 400hz coming out of the panel in AL conduit then to the cord reel right?

I have seen 120V, 15A and 20A and I was thinking it will be similar to that.

400 Hz comes with more voltage drop, skin effect and also I was concerned if there is OSHA rule for cord reel requirements

 

[drcampbell]

Skin effect isn't going to be significant. The skin depth at 400Hz will be almost triple the radius of a 10-gauge copper wire.

And nothing in the code singles out different frequencies. The voltage & current dictate the materials & techniques; frequency is irrelevant.

 

[PowerdT]

Skin effect isn't going to be significant. The skin depth at 400Hz will be almost triple the radius of a 10-gauge copper wire.

And nothing in the code singles out different frequencies. The voltage & current dictate the materials & techniques; frequency is irrelevant.

It will be alumunium wire. If frequency has nothing to do with installing cord reel on ceiling. What other factors should I be worried on the design? Such as safety isssue?

Is Article 400 has cable suitable for this situation?

 

[hbiss]

I meant 115Vac, 30A, 400hz coming out of the panel

It will be alumunium wire.

Why would you use aluminum wire for 30A?? Where would you even get it?

Is Article 400 has cable suitable for this situation?

You can choose anything from there suitable for your installation in conduit. THHN/THWN would be my choice.

-Hal

 

[Coppersmith]

For anybody who was wondering why 400 Hz is in use like I was, here is a good read on the history of electrical frequencies.

https://en.wikipedia.org/wiki/Utility_frequency#400_Hz

 

[PowerdT]

Why would you use aluminum wire for 30A?? Where would you even get it?

I read somewhere in different thread that, 400Hz should be in Aluminum

 

[hbiss]

I read somewhere in different thread that, 400Hz should be in Aluminum

IN aluminum and using aluminum wire mean two completely different things. Was that other thread here? I think somebody may have had the thought that 400Hz should be pulled through aluminum conduit. I don't agree with that. As far as I'm concerned it doesn't make any difference what you use.

-Hal

 

[drcampbell]

... somebody may have had the thought that 400Hz should be pulled through aluminum conduit. ...

"Somebody" might have been "thinking" that the higher frequency would result in higher inductive losses if it were in steel conduit.
But if there's no net current in the bundle of wires in the conduit -- the hot wires are paired with their corresponding return wires -- then there's no net magnetic field generated by the wire bundle and negligible induction losses.

 

[PowerdT]

IN aluminum and using aluminum wire mean two completely different things. Was that other thread here? I think somebody may have had the thought that 400Hz should be pulled through aluminum conduit. I don't agree with that. As far as I'm concerned it doesn't make any difference what you use.

-Hal

I see, thank you for the information

 

[PowerdT]

"Somebody" might have been "thinking" that the higher frequency would result in higher inductive losses if it were in steel conduit.
But if there's no net current in the bundle of wires in the conduit -- the hot wires are paired with their corresponding return wires -- then there's no net magnetic field generated by the wire bundle and negligible induction losses.

I believe there was planning to use 8ccc in a conduit.

 

[hbiss]

I believe there was planning to use 8ccc in a conduit.

Four hot wires with their corresponding return wires just like @drcampbell was talking about.

-Hal