RFI
[Top] [All Lists]

Re: [RFI] Galaxy Grow Light Ballast Update

To: jim@audiosystemsgroup.com
Subject: Re: [RFI] Galaxy Grow Light Ballast Update
From: Kim Elmore <cw_de_n5op@sbcglobal.net>
Date: Mon, 1 Feb 2016 18:13:35 -0500
List-post: <rfi@contesting.com">mailto:rfi@contesting.com>
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@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
> _______________________________________________
> RFI mailing list
> RFI@contesting.com
> http://lists.contesting.com/mailman/listinfo/rfi
_______________________________________________
RFI mailing list
RFI@contesting.com
http://lists.contesting.com/mailman/listinfo/rfi

<Prev in Thread] Current Thread [Next in Thread>