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

Jim Brown jim at audiosystemsgroup.com
Wed Dec 28 13:37:38 EST 2022


On 12/28/2022 7:27 AM, Paul Christensen wrote:
>> "Neutral to chassis ground and ground, ground, ground everything together, and to the 240 ground coming into the power supply."
> That's what ETO did in the Alpha 70/77 series amps.  It's not strictly a NEC violation because NEC is a premise wiring and safety standard, and not a product wiring standard.

If there IS a neutral, it must NOT go to the chassis, because it places 
a second bond on the system. In any power system, neutral must be bonded 
to ground at one, and ONLY one point, within a rather limited distance 
from the service. That bond is most commonly in the main entry panel.

Steve is correct, it IS a violation for neutral to carry load current. 
It used to be allowed, but code was changed many years ago, and older 
equipment is grandfathered.

> 
>> Use the common connection point between two 120 volt windings, wired in series, on the input of the HV transformer for 240 use.
> Yes, another common scheme.

That's what K4XU did in the original Ten Tec Titan to run the blower.

73, Jim K9YC


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