[Amps] What to do about 'Neutral' in HB amp?

[Paul Christensen]

>"If there IS a neutral, it must NOT go to the chassis, because it places a
second bond on the system."

Even if there is NOT a neutral, it's created by design fault in some amps
and appliances.  In the case of the 70/77 series amp, there's no separate
neutral conductor connection point unless the owner: (1) modifies the amp at
the power connector to isolate the blower return from the chassis; and (2)
runs 4-wire service to the amp receptacle.  

In case there's any confusion, it's wrong to allow an amp or appliance
chassis to function as a current-carrying neutral.   It is wrong today, and
was wrong in the past regardless of any code in effect or not in effect at
the time of product manufacture.  

The only legacy exception I'm aware of under NEC 250.140 for frames of
ranges and clothes dryers.  And, it's still wrong even if it's right under
the code.

Paul, W9AC