[HAM] Alignment of Start Motor. Warning about exposed AC mains

[John Doyle]

The three wire system that you are talking about needs some clarity. The 
"hot" wire will measure 110VAC to ground and also to the neutral. The 
neutral is bonded to ground. The neutral is known as a current carrying 
conductor. The third wire or "ground" is not supposed to be a current 
carrying conductor. It is present for safety and safety only. The only time 
that the "ground" wire carries current is in a fault condition.

All that being said there is no voltage drop between the neutral and ground 
as they are at the same potential.

Again, in either a two or three wire system with a stock B3, as long as the 
neutral wire is going to the motors and the hot to the switches there will 
be no voltage at the start motor.

For illustration purposes, let's suppose that a three wire plug was 
installed on a B3. The hot wire would go to the start/run switch, the 
neutral would go to both motors and the AO-28 xformer, and the ground wire 
would go to everything metal in the organ. With the start and run switch in 
the off position, you could meter from anything metal in the organ to both 
sides of the run motor and you will see no voltage. You could also meter 
from anything metal in the organ to both sides of the AO-28 xformer and see 
no voltage as well. This is because you would be metering from neutral to 
ground which is at the same potential.

JD
----- Original Message ----- 
From: "Kon Zissis"

> However with the three conductor  AC mains system  which has the "hot"
> active wire , the neutral wire and the separate earth ground this
> completely changes the situation so that there is always the dangerous
> live voltage present at the motors and the AO28 power transformer even
> when the organ is switched off.