[Hallicrafters] S38D Line safety

[Roy Morgan]

At 12:51 PM 12/5/2005, Glen Zook wrote:
>Replace the 2-wire cord with a 3-wire cord.  Connect
>the green (ground) wire to the metal cabinet.

and I wrote:
>Some folks say to use a three wire grounded line cord with the safety 
>ground (green) connected to the chassis and the other wires appropriately 
>connected. This may be all well and good, but you run the risk of tripping 
>ground fault protection devices, and if you hook it up wrong, the chassis 
>is still at line voltage.

I have though about this a little bit more.  If you get the Line and 
Neutral wires backwards (or, as I suggest, you have an improperly wired 
outlet)  you will apply full line voltage across the 0.02 uF capacitor, 
from line to safety ground.  If you have a GFI device it might trip. One 
capacitance calculator I located on the web figures the reactance of such a 
cap to be 132 kilohms. This might pass about a milliamp of current then. 
Enough to give you a bite, but perhaps not deadly.

BUT.. If the capacitor shorts, then you have full line voltage at 
considerable available current on the chassis.

Roy

- Roy Morgan, K1LKY since 1959 - Keep 'em Glowing!
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