[Milsurplus] Aircraft Electrical Question

[Mike Hanz]

I don't have any standards for after WWII, but perusing a number of 
manuals for equipment of that time, the 115 (nominal) vac is floating on 
both sides for both 400~ and 800~ power.  No attempt was made to balance 
it with respect to ground, nor to ground one side in the alternator or 
load equipment.  Part of the reason for that may be the need to 
accommodate the 80 volt British system, which apparently followed the 
same approach.

73,
Mike

On 1/12/2011 11:49 AM, Jack Antonio wrote:
> This is concerning an aircraft using 120V 400 cycle
> power. And I realize it may vary between aircraft,
> so I'm wondering if there is "standard practice"
> concerning this.
>
> Is one side of the AC line grounded? Is the 120V
> floating, or balanced with respect to ground?
>
> If one side is grounded, do they use a single point
> ground, or use the airframe as a return conductor?
>
> Looking at some gear here in the shack that uses
> 400 cycle, which is what got me wondering.