high frequency conductor rating/losses 1

[greenurth]

I'm seeking recommended published material concerning selection and use of standard building wire in the distribution of high frequency (~800 Hz) source voltage. The academic papers I've stumbled across so far have been thin on practical application guidance. Any forum help or insight is appreciated. _80127

 

[dpc]

800 Hz should not pose much problem. The inductive reactance of the wiring will be higher due to the higher frequency, giving you more voltage drop. So the distances will need to be kept much shorter than for a standard 50 or 60 Hz system. Aircraft electrical systems are often 400 Hz.

Also, the skin effect will make the resistance higher.

A standard Electrical Engineer's Handbook should provide you enough data on the wire characterisitics to work out an equivalent circuit at 800 Hz.

Unless you meant 800 kHz?

 

[waross]

It may help to know the nature of your intended installation.


Bill
--------------------
"Why not the best?"
Jimmy Carter

 

[greenurth]

Thanx for your responses. IPCEA P-43-457 was last issued in 1961 and I'm looking for a more recent computational treatment of the subject. The application is research and development activities throughout a new building. Various voltage and frequency power systems (800 cycles per second is correct) are programmed to be distributed throughout the facility.

I'm familiar w/the use of non ferrous raceway and when I apply the Table III CDF (Current Derating Factor) of .77 to a 4/0 cable I'm left with that conductor being good for 177A (NEC Table 310.16, 75C). Two #3s would provide equivalent ampacity.

Much of the material I'm coming across is heavy with error cancellation techniques. I'm not rejecting the need for detailed understanding of the phenomenon... I'm hoping to find a valid approximation in 'industry practice' type literature. _80128

 

[dpc]

Depending on the rating of the insulation, you may be able to base your derating on the 90 deg C insulation rating as a base value.

I would frankly be more concerned about any type of overcurrent device you might be using. You can probably find molded case circuit breakers and fuses tested and rated at 400 Hz, but I'm not sure anything has been tested much at higher (fundamental) frequencies.

If this is something that would actually be installed in a building, you would have to deal with all of the necessary agency approvals required for all of the electrical components.