[Amps] Re: SB-220 on 220V

R.Measures r at somis.org
Sat Dec 6 06:48:49 EST 2003



>I do not think that is correct.
>
>My SB-220 does not use the neutral.  It uses
>hot-ground-hot in the power cord.   The "third" wire
>is connected to the chassis, and goes to the AC line's
>ground, not the neutral.  The schematic supplied with
>mine clearly defines the third wire as "ground" and
>does not refer to "neutral" at all.  Nothing on the
>primary side of the wiring is connected to the
>chassis.
>
>The 120VAC fan is driven from one of the primary
>windings of the power transformer when it is wired for
>220VAC - essentially a center-tap.  The "third" wire
>is not used for carrying any current, except fault
>current.
>
>If you ran the neutral wire into an SB-220, I am not
>even sure where you would connect it.
>
**  I connect the Neutral on the SB-220's 240v 3-wire line cord to the 
chassis.  Normally, no current flows in this wire, but the 
Neutral-chassis connection does serve to prevent much voltage from 
appearing on the chassis during a fault. 


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