Electrical Fire! Help!

[mr_tripp]

Photo: https://docs.google.com/open?id=0B7ND8aBQ_BXGR0wzN2JRVGt5UDg

I have a electric kettle and I use a 2000W element from Home Depot. I use a Ranco controller and Shock Buster GFCI from Lowes. I have used my system about a dozen times and no problems. The other day I started an electrical fire. The black cable melted. I technically saw no flames, just smoke. Luckily I was in the room and was able to disconnect the cords before much more damage could have happened. Do you have any idea for what might have caused this. I'll try to describe my setup as much as possible and give some possible problems:

1. The ground wire came lose on the kettle. It also had JB Weld on the end of it because my hole was cut to large so I had to patch it.

2. I have a 220v dryer connector and I had an electrician re-wire it to make two 110v receptacles instead of the 220v. (I know I should just use a 220v element, but then I can't use my ranco controller)

3. The Shock Buster says 1875 Watts on the back and the element is 2000 (I think, again it's from Home Depot)

4. The Ranco controller is using a standard orange extension cord. I tried to use heavy gauge wire, but it always came loose, so now it is braided wire, not solid copper. I opened the Ranco controller and there was not burns on any of the cables inside, just the male plug that went into the Shock Buster. The other male and female connectors from the element to the Ranco also did not have any burns.

5. The steam from the boil was pretty close to the electrical outlet. I actually though the smoke was steam from the boil at first.


Thanks for any help.

 

[whoaru99]

Two things...the components you're using are overloaded if, in fact, you have a 2000W element (16.7A) on devices spec'ed for 15A. That is a 15A plug and receptacle.

And, based on the burned mark on the plug it looks like you had a bad connection at the screw clamp/connection inside there. Bad connection = high resistance = voltage drop (combined with current) = heat.

 

[WPStrassburg]

you plugged something from The Depot into something from Lowes.... It was bound to fail!

Then you overloaded it while subjecting it to a steam bath with no ground connection with undersized extension cords fed from a hacked dryer connection( that could've been used with a Ranco since they can support 240v), but other than that there shouldn't have been any issues.

I'm thinking items 1-5 were the source of your issues and luckily they didn't show up on the previous dozen batches. Make sure you use the correctly sized components(wire, controller, protection, outlets, ect) for your application or have that electrician review your rig before you brew again. This may be harsh, but you should be dead right now with what you had cobbled up, so please get all the issues worked out before you brew with this again.

Did you get the beer to the fermenter?

 

[passedpawn]

Look at the picture. You can see where the heat was. Inside that DIY plug.

What must have happened (not the first time on this forum) is that the wire was not securely connected to the prong in that 110V plug. A loose wire has higher resistance than normal, and current through resistance = heat. If it screws down, maybe the screw wasn't tight.

I think your whole system sounds flawed, actually, but the problem was probably just a wire that wasn't tightly screwed down in that plug.

 

[beluedog]

you plugged something from The Depot into something from Lowes.... It was bound to fail!

true that

 

[OatStraw]

you plugged something from The Depot into something from Lowes.... It was bound to fail!

Then you overloaded it while subjecting it to a steam bath with no ground connection with undersized extension cords fed from a hacked dryer connection( that could've been used with a Ranco since they can support 240v), but other than that there shouldn't have been any issues.

I'm thinking items 1-5 were the source of your issues and luckily they didn't show up on the previous dozen batches. Make sure you use the correctly sized components(wire, controller, protection, outlets, ect) for your application or have that electrician review your rig before you brew again. This may be harsh, but you should be dead right now with what you had cobbled up, so please get all the issues worked out before you brew with this again.

Did you get the beer to the fermenter?

My Wife and I are laughing so hard right now at this response. Bravo!

Im glad that OP can live to brew another day.

 

[alien]

I've had a similar problem in the past and it was due to a bad connection inside the socket.

 

[smittygouv30]

This makes me a little nervous! What's the best way to make sure the wire terminal connects stay together? I'm using the switchcaft plugs and each receptacle has the 4 male connects. I slid the female ends on and tried to crimp them the best I could. They pass the tug test but I'm not trying to start any fires.

 

[aquenne]

not knowing all the details, i would get some insulation/shrink tubing on the exposed terminals, those wires are not secured sufficiently.

 

[smittygouv30]

That plate is mounted on the top of my spa panel. What would you do different to make it more safe?
Individual shrink tubing to cover the terminal ends?
Solder the connections?
Silicone to cover the connections?
Leave it be?

I'm concerned as I plan to make a similar set-up at the control panel.

 

[whoaru99]

I would re-terminate all those push-on connections. Don't believe the intent is to smash them down after they're pushed onto the mating terminals. The spring tension, for lack of better terms, of the push-ons in their normal, non-smashed state is what's relied on for the contact. Don't care much for push-on terminals in (relatively) high current applications, myself.

 

[kal]

What is the current/voltage rating on those black connectors you have there?
What kinds of plugs are these?

In a different picture it looks like they're connected to a 50A breaker, but I've never seen a 50A receptacle with only push/crimp on connectors like this, especially ones that are so close together, almost touching.

Normally a NEMA 14-50R receptacle (meant for 50A/240V) is really big, with screw connection points that are well spaced out.

Here's a typical NEMA 14-50R receptacle that you'd use for a kitchen stove outlet:

You push the wire in and screw down tightly.

Kal

 

[whoaru99]

Read all about the Switchcraft connectors here: https://www.homebrewtalk.com/f170/switchcrafts-plug-outlet-option-369044/

 

[Bobby_M]

A 2000 watt element on 120v requires at least 12 gauge wire and should be plugged into 20amp components. 1875 is the max rating on the shock buster, you exceeded it. That plug is for 15amps and therefore the connections are only build to accept 14 gauge wire. I'd start over. Get some decent 12/3 SJ cord.

By the way, the ranco is only rated for 15amps resistive on 120v so that's overloaded too.

 

[kal]

Read all about the Switchcraft connectors here: https://www.homebrewtalk.com/f170/switchcrafts-plug-outlet-option-369044/

Ah! Ok. So they're the (somewhat controversal for AC mains use) Switchcraft connectors.

I don't like seeing uncovered spade terminals used with that amount of heavy gauge wiring coming off them. Bend one of the wires somewhere either on purpose because you're moving something in the box (or bang into it or drop it) and you could have a couple of spades touch.

My 2 cents but I'm starting to change the topic...

Kal

 

[Psych]

Note to would be e-brewers: do not disregard the following statement which occurs in some form or other in probably every single e-brewing thread here:

"Do not load your components past 80% of their amperage rating!"

Loading to 120% on more than one component is ridiculous, come on.

 

[Kaz]

Ah! Ok. So they're the (somewhat controversal for AC mains use) Switchcraft connectors.

I don't like seeing uncovered spade terminals used with that amount of heavy gauge wiring coming off them. Bend one of the wires somewhere either on purpose because you're moving something in the box (or bang into it or drop it) and you could have a couple of spades touch.

My 2 cents but I'm starting to change the topic...

Kal

Those are professional loudspeaker connectors, not really intended for continuous current draw applications. They are usually rated for a peak amperage draw but that is not necessarily the rating for continuous draw as speaker amplifiers are generally not putting out a continuous steady signal under normal operation. You can find lots of specs on them on their originators website Neutrik

http://www.neutrik.com/en/speakon/

I probably have a thousand of those in different flavors in my shop, they are great for speakers, I wouldn't use them so much for high current home appliances. Neutrik does make a line of similar power connectors called PowerCon but not in a 4 pole 50A 208VAC flavor.

 

[jeffmeh]

Those are professional loudspeaker connectors, not really intended for continuous current draw applications. They are usually rated for a peak amperage draw but that is not necessarily the rating for continuous draw as speaker amplifiers are generally not putting out a continuous steady signal under normal operation. You can find lots of specs on them on their originators website Neutrik

http://www.neutrik.com/en/speakon/

I probably have a thousand of those in different flavors in my shop, they are great for speakers, I wouldn't use them so much for high current home appliances. Neutrik does make a line of similar power connectors called PowerCon but not in a 4 pole 50A 208VAC flavor.

There is much discussion around this in the other thread referenced. The Switchcrafts do have different ratings than the Neutriks. From what I gather, they will handle the load, but connecting or disconnecting while powered on is highly discouraged. I am intrigued by them, but will probably go with something less "controversial" when I finally get the time and the funds to build.

 

[mr_tripp]

Thanks everyone. I'm making some adjustments and will report back but I have a quick question. What is the best way to ground to the pot. I have some stainless steel nuts and bolts but how do I prevent leaks?

JB weld?
Rubber washer?
Silicone tape?
Other ideas?

 

[passedpawn]

Thanks everyone. I'm making some adjustments and will report back but I have a quick question. What is the best way to ground to the pot. I have some stainless steel nuts and bolts but how do I prevent leaks?

JB weld?
Rubber washer?
Silicone tape?
Other ideas?

drill a hole near the top and bolt it in there with a nut and lock washer and ring terminal, or put the hole in the handle if it is solid to the pot.

 

[ChuckO]

I silver soldered a stainless bolt to the pot near the element and use a crimp on ring terminal on the ground wire held down with a stainless nut. Keeps from drilling another hole in the pot.

 

[biertourist]

Neutrik does make a line of similar power connectors called PowerCon but not in a 4 pole 50A 208VAC flavor.

I'd love to chime in on this as someone who's currently using the SwitchCraft connectors for all leads and from my spa panel to my control panel.

If I had it to do over again, I'd probably NOT go with the SwitchCraft connectors again; although these PowerCon connectors address many of the issues that I have with the SwitchCraft connectors.

-I'm also nervous of a spade connector coming lose or touching another spade connector either inside my control panel or cable. Although hard to see in the picture that was posted here, there IS a plastic separator that keeps the connectors separated from one another, it is NOT much of a stretch that two of them might touch together.

These things ARE time consuming (especially the cable connectors) to get right; there's a very small margin of error that you have to work within between the cable sheath and the end of the individual wires so that you'll get a good full-on connection inside the connector and so that the cable glands can crimp down on the sheath; crimping all those spades is also pointless once you see that the PowerCon connectors don't require spades and are just simple "push in and screw down" connectors. You have a DRAMATICALLY reduced risk of two conductors touching each other in the PowerCon connectors, too.

I'm going to buy liquid electrical tape to try and insulate those SwitchCraft spade connectors and try and reduce the risk that two of them will touch and create a dangerous short.

It's also pretty clear to me after wiring a few of these SwitchCraft connectors that they were NOT designed to be used with 10/4 wire as the "boot" (it's what they called it in this video: ) just won't fit over 10/4 wire -I had to grind down the inside of the boot to make the ID big enough to fit 10/4, even 10/3 with a thick jacket (the HomeDepot stuff) was a VERY tight fit and I had to grind it down a little bit, too.


For me the PowerCon connectors move into the realm of being quite acceptable, but I will not use the normal SwitchCraft connectors in my next build.

Again my two complaints are: ease of proper installation, and safety because of the spade connectors.

They are priced fantastically, take up a small amount of room in a control panel, look fantastic, and provide great functionality, but the PowerCon connectors additionally address my two previous concerns and safety isn't a minor one.


Adam
P.S. If you over tighten the SwitchCraft control panel connectors even a TINY bit they WILL break; the plastic is very brittle; do NOT over-tighten.

 

[biertourist]

Another thing worth noting: the PowerCon connectors only go up to 32amps; so they are NOT to be used for a 50amp run between a spa panel and your control panel. -If you're building a 50 amp control panel, the giant ugly electric oven plugs or the NEMA plugs specified in Kal's build seem to be your best / only? options.

For those of us building 30 amp breweries/ control panels, there's still a lot to be said for the PowerCon plugs, IMHO.

Adam

 

[biertourist]

Crud!
-I finally learned to read, apparently...

The Neutrik PowerCon connectors, unlike their SwitchCraft cousins, are only 3 contactor and won't work for the purposes of going between a GFI breaker panel and your control panel.
-They should only be used for going from your control panel to your electric elements. After using the SwitchCraft connectors between my breaker panel and control panel, I can now only recommend Kal's NEMA plugs for this application.

-I REALLY wanted to find a less expensive alternative; there's certainly somethings in Kal's build that are way overbuilt for my personal needs and budget (personal preference, not a dig on your amazing build), but that particular NEMA plug does not seem to be one of them.

Sorry to be the harbinger of bad news; please don't shoot the messenger.


-Also: Given the cost of getting all the proper connectors and wiring to support a GFI breaker box, I'm starting to think that just buying a (fairly expensive) replacement GFI breaker and installing it in your main breaker box is actually a better option if you have the choice (likely ends up being the same price either way). This also means that you don't have ANY unprotected power anywhere near the "Wet zone" of your brewery. (If you get your spa panel GFI breaker box wet, you can end up in a dangerous situation; -I actually remember a thread on here on just that subject, too...


Adam

 

[smittygouv30]

Hey Adam,
I'm the original poster of the pics of the hacked up spade terminals on the switch craft receptacles. I am still early in the building phases but am still planning to use the switchcraft plugs (already ordered and received). I want to use them from the wall receptacle to spa panel, spa panel to control panel, and control panel to element. I'm a little discouraged by your comments but after installing the spa panel receptacles I have to agree with you. They are a pain in the butt to install and I too fear that a terminal will come loose and all havoc will break loose. I'd rather not retreat now but I do want to know what I can do to minimize any risk. I am planning to start over, solder the wire connections to the terminals and then to the receptacle blades. I'll then use heat shrink to insulate around the ends. I know nothing of this liquid electrical tape, but am intrigued.

So, is there anything else I/we can do to make sure that the connections don't move? Anything else to minimize any risk? I don't mind the extra installation work as I realize that it is saving significant money and I feel they look a little nicer than the NEMA plugs.

Thanks,

Corey

 

[biertourist]

Smittygouv,

Don't be discouraged; I'm already doing exactly what you're doing (Switch Craft connectors for everything); with 10/4 wire between the spa panel and the control panel and 10/3 to the elements you should be fine. -I doubt that they'll come off -the pressure is actually holding the spade connectors on; when they bend could two of the spades actually touch? -I definitely think it's possible, hence shrink wrap or liquid electrical tape; now that i think about it I'll have to actually disconnect every single spade connector to even liquid tape them so I might as well just shrink wrap them....

The liquid electrical tape is sold at any of the big box home stores in the electrical section and is in a jar that looks like rubber cement; it's goes on as a liquid with a brush that's attached to the lid and is non-conductive when it dries so you just sort of "paint" this goop around whatever it is your trying to insulate. I guess for this application shrink wrap might be better. (Definitely less messy)

Adam
Adam

 

[tyfernandez]

I too have used the Switchcraft connectors. I haven't used the panel mounts, just the male and female cord connectors. It was pretty painful wiring them up, but once I did a couple it got easier. I used plenty of shrink wrap to cover any exposed metal. I really don't see them coming off the terminals though, once you assemble the plug there is hardly any wiggle room. Keep everything tight and you should be okay.

As far as the panel mounts go, Neutrik does offer Speakon with screw terminals.

http://www.jacksmusicfactory.com/default.asp?productid=91521_Neutrik_NL4MP-ST_4_Pole_Speakon

I do recall someone saying that only Switchcraft were rated for continous usage, but they're both Speakon standard connectors. Who knows though.

I debating whether to scrap my Speakon and switch to the Powercon. I've had no issues thus far, but is it really worth the risk?


EDIT:

Curiously looked on ebay for the Powercon and found generic connectors for 99 cents for both the cord and panel connector. They have type A and type B. Even with the 7 dollar shipping charge, not a bad price if you need a few. Wish I saw this before the speakon connectors

http://www.ebay.com/itm/370641946200

 

[smittygouv30]

Those screw on terminals look fantastic but the specs read "up to 12 gauge wire". Unfortunately 10 gauge or lower is the norm and deems these worthless for our application. Am I missing something?

 

[whoaru99]

You mean besides that Neutrik says "speakON is NOT to be used as an AC mains or power supply connector!"?

 

[tyfernandez]

I've done a little "research" tonight, reading up in some A/V forums. I'm quoting basically third hand information but it seems to make sense to me. Here is the thread I'm referring too.

http://forums.prosoundweb.com/index.php?topic=110300.0


From what I gather from it seems people feel these aren't rated for AC mains because all the contacts mate at once when connected. For it to be UL rated it would have to have a ground that connects before the load, hence why the ground plug is longer than the other plugs on a traditional 3 prong plug.

Also it seems that since they have their roots in the sound and lighting industry things seem to be unplugged and re-plugged while on, thus making it unsafe to use. And then there is also the confusion factor that someone might plug a AC line into a speaker outlet as all the connectors look the same.

I'm no electrician or even am claiming to be one, but it seems like if you never disconnect these or connected these with the power on you'd be okay. They are rated to handle the current, just not properly grounded to plug in hot.