400 hz breakers

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PIKEY

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i need to install a 400 hz distribution panel in an aircraft mockup. im wondering if anyone knows what kind of breakers out there are rated for 400 hertz? ive noticed that some have 60 hz ratings on the side of the breaker and others dont give a hertz rating. ive called a few electrical wholesalers, and they dont have a clue what im talking about. is there anybody out there?
 
PIKEY said:
i need to install a 400 hz distribution panel in an aircraft mockup. im wondering if anyone knows what kind of breakers out there are rated for 400 hertz? ive noticed that some have 60 hz ratings on the side of the breaker and others dont give a hertz rating. ive called a few electrical wholesalers, and they dont have a clue what im talking about. is there anybody out there?
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Fuses can normally be used by increasing the nominal value about 25%.

Square D has a data sheet on this for some of their breakers. It indicates that interupting ratings go down a lot as frequency increases. At 400 Hz, the interrupting capacity is only about 10% of what it was at 60 hz. The instantaneous trip point increase a LOT, and the overload point drops some.

see page 3 of this document.

http://ecatalog.squared.com/pubs/Ci.../QO-QOB Circuit Breakers/QO-VH/0100DB0101.pdf
 
re:

re:

so they dont actually say that the ul rating applies to using a square D breaker in 400 hz applications, but they give the specifications if you do?
 
PIKEY,

I was searching through the web and came across a site for Boeing. It stated that the aircraft uses 400 Hertz.
What is the reason for that?


Justin J. Walecka
 
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400 Hz is moor stable at altitude some AC have open buss distribution some are located in un-pressurized sections of the fuselage thin air less dielectric

400Hz is less of a irritant to sensitive electronics and some of the radio (com) bands HF, UHF, VHF LF VLF I forget which ones but that is the retoric the Navy gave us


Charlie
 
JJWalecka said:
PIKEY,

I was searching through the web and came across a site for Boeing. It stated that the aircraft uses 400 Hertz.
What is the reason for that?
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Very simple answer. The size and weight of a 400Hz generator is about 1/3 of it's 60HZ cousin for the same amount of KWH.
 
JJWalecka said:
Dereckbc,

Do you know of any other equipment that uses high frequency?

Justin J. Walecka
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The woodworking industry, with routers directly coupled to motor shafts, needs more than the 3600 rpm we can get with 60 Hz. Numerous applications use MG sets, 400Hz, and 400Hz motors to run at 24000.

George
 
JJWalecka said:
Dereckbc,

Thank you for your time.

Do you know of any other equipment that uses high frequency?


Justin J. Walecka
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Boats planes, spacecraft, or anywhere lightwieght and spcase is a concern. The trade off is voltage drop.
 
400hz breakers

400hz breakers

so just about every breaker manufacturer will allow you to use there breakers with 400hz systems as long as you use there charts for derating(explore their websites). most will also calibrate their breakers for a fee; which i am doing with the siemens QP snap style breakers. the fee was only about $5 a breaker. not to bad.
 
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