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Philci model 116-121
7/27/2014 4:58:35 PMRogeld
I was just wondering if it is normal to get 57vac from chassis ground to earth ground?
Radio plays great and has been recapped and all out of tolerance resistors have been replaced.
7/27/2014 5:22:53 PMNorm Leal
Hi

Some radios have a capacitor from each side of the AC line to chassis. If you radio has this chassis will be half AC line in voltage. If you radio is this way nothing to worry about.

Capacitors pass AC voltage but at low current depending on value.

Norm

:I was just wondering if it is normal to get 57vac from chassis ground to earth ground?
:Radio plays great and has been recapped and all out of tolerance resistors have been replaced.
:

7/27/2014 5:38:43 PMrogeld
:Hi
:
: Some radios have a capacitor from each side of the AC line to chassis. If you radio has this chassis will be half AC line in voltage. If you radio is this way nothing to worry about.
:
: Capacitors pass AC voltage but at low current depending on value.
:
:Norm
:Thanks Norm, I thought that was happening. Yep very low current. I guess that is one reason to ground the radio.
::I was just wondering if it is normal to get 57vac from chassis ground to earth ground?
::Radio plays great and has been recapped and all out of tolerance resistors have been replaced.
::
:
:

7/27/2014 6:24:40 PMCV
It's normal since both sides of the AC input are connected to caps which are then connected to chassis ground. This is primarily done to prevent RF trash that is generated inside the set from getting onto the house AC power line and interfering with other household radios. To a much lesser extent the caps also serve to suppress RF garbage coming in over the power line.

Could be problematic if the cap that happens to be connected to the "hot" side of the power line shorts out. In that case the chassis would then be at 117VAC with respect to neutral (and earth ground).



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