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-   -   Help with Element Cord and Outlet (http://www.homebrewtalk.com/f170/help-element-cord-outlet-368912/)

Munchman 11-20-2012 02:06 AM

Help with Element Cord and Outlet
 
I'm currently attempting to put together a panel build just like Johnodon's build on here (PJ diagram Auberin-wiring1-a4-5500w-BIAB-30d6.jpg). I've bought almost all the parts and then I was looking at the diagram and realized my flush mount outlet for the element is not the same as the one in the diagram picture. I bought the only 3 wire range cord I could get at Home Depot and it was also linked on PJ's brewery parts spreadsheet (http://www.homedepot.com/h_d1/N-5yc1v/R-202214665/h_d2/ProductDisplay?langId=-1&storeId=10051&catalogId=10053#.UKryAmf_KSo). I also bought the flush mount outlet to match it.

However, the plug has the L shaped prong on the bottom and the outlet says non-grounding. The 3rd prong is meant to be connected to a neutral. PJs diagram shows connecting the 3rd prong to ground, not neutral obviously. I'm wondering, though, does it matter if I connect that neutral prong to ground anyway? Is there something in the plug construction that would prevent it from working with a ground connection instead of a neutral or is it not sized appropriately for ground? I'd like to be safe, so if it means eating the outlet that's fine. But if it's safe to use I'd rather do that.

Thanks!

whoaru99 11-20-2012 03:21 AM

Ehhh, disregard.

ajdelange 11-20-2012 04:47 AM

I'm a little confused by your post as you say the diagram you are looking at shows the third prong connected to earth/ground. This implies that the system is a 240V only system (i.e. there are no 120V loads in it) as the earth wire is not permitted to be a current carrying conductor under normal operating conditions. Lots of houses are wired for clothes dryers with two hots and a ground because old clothes dryers had no 120V stuff in them. The earth wire was connected to the frame.

More recently appliances (ovens and dryers) had 240V and 120V loads and houses were wired with two phases (red and black hots) and a neutral (white). For those installations it was, for a time, permissible to tie the frame to the neutral (white). In a new installation you must run 4 wires (phases, neutral, earth) and use 4 prong outlet and plug. The earth wire is connected to the frame of the equipment.

[Edit]: If clothes dryers were in fact run with two hots and ground only that was a long long time ago as was pointed out in another thread. I was thinking of another circuit in my house which goes to a compressor. A panel wired in 1988 has 2 hots and neutral going to the clothes drier.

So a lot depends on what is in the box into which you are going to install the outlet. If it is two insulated wires plus a bare wire you can't do it if there are any 120V circuits in the device you are connecting (unless they are derived from a transformer within the device). If it is red black white without earth then you can use the outlet you have (non grounding) and connect the neutral to the third prong and the frame. Note that leakage to the frame will not result in a GFCI trip with this arrangement. If it is three insulated wires plus ground wire then you must use a 4 prong outlet and plug.

Munchman 11-20-2012 12:44 PM

Thanks for your reply. Ugh yeah I'm sorry I was horribly unclear. My panel is going to be supplied power from a 30 Amp 2 pole GFCI breaker connected to a 4 prong dryer outlet so it'll have 2 hots, neutral and ground. What I was asking about was the outlet in the panel that the element will plug into. Per PJ's diagram that is going to be 3 wire with 2 hots and a ground. The issue is that I bought a cord and outlet that have a configuration that is normally used for 2 hots and a neutral setup (old style dryer). So since I already installed the outlet in the panel, I was wondering if it mattered if that 3rd prong is used for neutral or ground. The ground will still be properly connected in the panel and at the pot.

ajdelange 11-20-2012 01:10 PM

You would want to connect the ground as the third wire on the cord will go to the grounding lug on the heating element. When you say the ground will still be properly connected to the pot does that mean there is a separate ground to the pot? If so then you must connect the ground on the element to the grounding wire as if you connected it to the neutral you would be joining neutral and ground and that is, in the first place, a code no no and, in the second place, would trip a modern GFCI.
Also, if you connected the neutral and there were a fault to the neutral the GFCI would not detect it.

I guess we should also consider that you are using an outlet marked 'non grounding' as a grounding outlet and that is clearly a code violation. You should be using a 6-30 plug and receptacle. There is no reason that I can think of that using the plug and receptacle you have wouldn't work and there is no reason it wouldn't be safe unless you have other non grounding equipment around with the mating plug. There are reasons for the things in the code. My main concern in this area is that some insurance adjustor might use this as a 'gotcha' but then I'm pretty sure that there are already plenty of those in most of our breweries.

Munchman 11-20-2012 02:49 PM

Cool, thanks. I would never be connecting neutral to ground. I agree that I would be using a plug configuration for ungrounded applications, but I'd never be plugging it into anything besides my control panel. So I think the danger there is minimal. The insurance thing is a concern, but like you said I think there are other similar issues in my electric brewery. I will be wiring the GFCI breaker and outlet myself for one.


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