[RFI] Galaxy Grow Light Ballast Update

[Kim Elmore]

I respectfully disagree. GFI isn't intended to prevent a shock: it's intended to prevent death by electrocution. I suspect they do that admirably even with 600 uH total inductance split over two legs. I also doubt that GFI circuits are intended to protect against RF. I don't know how long a bit of wire is needed to get 300 uH but I'll bet it's pretty common. 

It's probably pretty easy to estimate the current rise time across 300 uH given series R an zero source impedance and I'd do it but I'm on the road. Overall, 'm not convinced 300 uH in each leg presents a significant hazard or delays a circuit breaker trip by a dangerous period. 

Kim N5OP

"People that make music together cannot be enemies, at least as long as the music lasts." -- Paul Hindemith

> On Feb 1, 2016, at 16:58, Jim Brown <jim at audiosystemsgroup.com> wrote:
> 
>> On Mon,2/1/2016 1:19 PM, Tom Thompson wrote:
>> I respectfully disagree.  The choke in the green wire and the common mode choke both are 300uH.  A short circuit current between the hot and the green wire would pass through both chokes in series. At 60 Hz the total impedance is 0.2 ohms which is not going to affect the breaker or fuse  blowing.
> 
> But it's NOT 60 Hz, it's an impulse. And if the choke is effective at killing RFI, it's got significant resistive impedance at the frequencies of that impulse.
> 
> The question is not WILL it blow the fuse/breaker, but will it blow FAST ENOUGH to protect someone from electrical shock.
> 
> 73, Jim
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