GFI breaker pricing... this can't be right

[bdjohns1]

Even if there was a cycle limitation, how often are you likely to hit the e-stop? I've used mine exactly once, and that was during testing.

Officially, GFCIs should be tested monthly.

 

[DustBow]

Still thinking about this...on one hand I see your points about GFCIs having a limited "life" or number of cycles so you don't want to use them too much or rely on them for an e-stop. On the other hand, how often do you really use them? It's not like they are the on/off switch - ideally, you would never have a situation where you have to push it.

Then again, you should test the e-stop and GFCI often enough (before every brew?) to make sure they are working and properly protecting you before you start throwing 240v into big steel containers of liquid......
So if you should test your GFCI regularly, you are still putting more duty cycles on it which is shortening its life (in theory)....it all just seems like a circular argument, especially when you factor in the very limited use of these brew rigs compared to an industrial setting (if you brew twice a month, that's still only using these things a couple hours per month)

Would it be ideal to have both options - and E-stop to trip the GFCI and another stop-button to contain the power to the contactor? Seems like tripping the GFCI is actually safer because the GFCI protection should be upstream and that would stop 100% of power from even getting to the control box.

Do they make a mushroom buttom DPST switch that you could just run both hot 120v legs through right at their entry into the panel? Or just use a "regular" DPST switch at the beggining of the wiring in addition to the end right before the element connection?

Sorry for all the questions, not trying to argue at all - just trying to truly understand everything before progressing. I know this is serious stuff. Thanks for all the info

 

[lschiavo]

Here's one study from mikeholt's site: http://www.mikeholt.com/documents/freestuff/NEMA-GFCI-Field-Test-Survey-Report-January-2001.pdf

I didn't read the whole thing. I searched the document for "cycle" and had no results. Can you point me to the section?

Do any manufacturers list a cycle rating for their products like they do for relays?

 

[yjfun]

Its in UL standard 489

http://static.schneider-electric.us...nsulated Case Circuit Breakers/0613DB9902.pdf

I couldn't find anything specific to gfci's or smaller than 50 amps but it looks like UL certification requires 6000 on/off cycles or 50 fault trips.

 

[zeus53219]

Circuit breakers measure life-time expectancy cycles in the thousands, where as quality contactors/relays measure in hundreds of thousands, and some times millions. In industry standards it is not recommended to use any type of circuit breaker as an e-stop. The only benefit I see in doing this is, if the inside of your control panel is saturated in liquid where your incoming power comes in, but if this is the case and your panel is properly grounded the gfci will trip anyway in a harmful situation. Not saying it cant be done, just not recommended in industry. Seal your panel good, ground everything correctly, and place an e-stop on main power contactor for proper piece of mind and longevity of yourself and your components.

 

[passedpawn]

what I use for my 240VAC cutoff:

This (home depot)

inside this weatherproof housing (home depot)

 

[DustBow]

Passed down, I saw that in another thread not too long ago, I think I might have to set up the same thing when I run the 240 line. If something is going wrong during a brew that has me worried, I'd rather reach for that than my (probably metal) control panel.
That will shut off all power before it even gets to my control box or brew rig.

Wow $11, nice:
http://www.homedepot.com/h_d1/N-5yc1v/R-100356941/h_d2/ProductDisplay?catalogId=10053&langId=-1&keyword=leviton double pole&storeId=10051

 

[passedpawn]

Passed down, I saw that in another thread not too long ago, I think I might have to set up the same thing when I run the 240 line. If something is going wrong during a brew that has me worried, I'd rather reach for that than my (probably metal) control panel.
That will shut off all power before it even gets to my control box or brew rig.

Wow $11, nice:
http://www.homedepot.com/h_d1/N-5yc1v/R-100356941/h_d2/ProductDisplay?catalogId=10053&langId=-1&keyword=leviton double pole&storeId=10051

I have another one of those on my control panel to just turn off the 240 to the element - leaves the pumps and PID powered.

 

[DustBow]

So you use that instead of a contactor and coil?

 

[passedpawn]

So you use that instead of a contactor and coil?

Yep. Whatcha think about that? I've used it for about 50 batches, still going strong! You can see my box with that switch on it here.

 

[DustBow]

I'm loving that switch, was at HD tonight for other things and took a look, feels nice and heavy. Can't beat it for the price, availability, ease, etc.
I've seen that tool box thread before - very nice. I'm looking at a much simpler build but I still might borrow the idea. HD had a smaller version of that box on special for a cheap price.....