safety first...

[Bsquared]

First of all Id'd like to thank Pj and Kal for the help building my system and making it safe. But after 3 years, I have finally had a failure and it was not a big deal because of PJ and Kal.

Mid boil my circuit breaker pops and after a quick inspection I find the plug had over heated and melted. After swapping out the plug for a new one I was able the finish the brew. At the end of the brew I notice I can't turn off my kettle, I assume the SSR failed open and was giving the element 100% power and possibly resulting in the plug melting.

I'm thinking Im going to upgrade my wiring to the element from 10 gauge to 8 gauge wire.

Thought Id share.

 

[Brettomomyces]

Thanks for that, I'm going to knock on wood that my panel never melts anything without my intention. Also, good thing you had a spare plug! I'd prolly pop one off the other 240v element, but that would make for a pita brew day.

 

[watermelon83]

After 3 years of cycling those terminal screws probably worked loose. Causing increased resistance, and therefore amprage, resulting in your failure. Heavier hard to work with wire won't help.

 

[Jaybird]

After 3 years of cycling those terminal screws probably worked loose. Causing increased resistance, and therefore amprage, resulting in your failure. Heavier hard to work with wire won't help.

Totally agree man! I bet you could have saved this by doing a simple PM of your system every 5-6 brews ...


Sorry.... 18 year career electrician here. I am all about PM in an electrical system if you can. Just part of the program of having an electric brewery IMHO

Glad to see it was a simple deal for you!

Cheers
Jay

 

[dyqik]

The compressors on our cryogenic systems at work usually kill their 30A three phase twist lock plugs in about 2-3 years, due to overheating as the resistance of the plug and wire connections increase. We have to replace them when they burn up (they usually don't blow the breaker). They do often run continuously for a week at a time, which doesn't help the lifetime.

 

[TimBrewz]

This is good to know. I just got my system working, and I will surely to the PM as Jaybird suggests.

 

[part16john]

Pm?

 

[BrokenHorn]

PM = Preventative Maintenance

 

[part16john]

Thanks

 

[Bsquared]

This is some great advice! I've gone through the panel several times checking connections and re tightening loose connections that at the time I was baffled why they would be loose, but after reading this it makes total sense. But never the plugs. I'll add this to my protocol! thanks guys

 

[processhead]

After 3 years of cycling those terminal screws probably worked loose. Causing increased resistance, and therefore amprage, resulting in your failure. Heavier hard to work with wire won't help.

+1 on the importance of system PM.

One minor correction... a loose connection won't increase the amperage in the circuit.

A loose electrical connection does result in localized higher resistance which translates to heat/failure.

 

[watermelon83]

Lol you're right. Stupid math!

 

[Hello]

Well I for one am glad for this PSA. My electric brewery is underway and I would have never guessed that I should consider any PM.

Sorry that it happened, it looks well contained though and it didn't explode.

 

[barnaclebob]

Why is that wire so mangled? Was it like that on installation?

 

[passedpawn]

I had the same happen about a year ago. I think mine was on a terminal block. It had loosened over time, either at the screw or inside the crimped faston. Can't remember now.

Your system should be able to run at 100% without melting down. In fact, that would be the first test I'd do with a new system. Fill kettle with water and let it rip.

 

[stlbeer]

I had a loose connection on a mechanical relay that caused a similar issue. It triggered me to check all of my connections. I was quite surprised by the number of connections that had loosened up. Mostly on the 220v components.

 

[iijakii]

Yeah I've been tempted to go through and solder up some of my connections. A few of my terminals aren't too snug. I crimped the spaded a bit with some needlenose and they seem fine, but I know that's not the best practice.

 

[Riot]

Don't use pliers to crimp spade terminals on, a decent wire crimper is only worth like 15 bucks

 

[iijakii]

Don't use pliers to crimp spade terminals on, a decent wire crimper is only worth like 15 bucks

I meant my wire's spades going to an outlet. Just not that tight on a couple of them even though the right size spade.

 

[passedpawn]

Don't use pliers to crimp spade terminals on, a decent wire crimper is only worth like 15 bucks

I used one. A big heavy duty sucker. Still happened.

 

[Bsquared]

Why is that wire so mangled? Was it like that on installation?

No that was from the heat that melted all the plastic, I had to pry the plug apart and clip the wires to attach the new plug so I could finish brewing.

Also When it first blew the circuit breaker, I opened up the control panel and checked the connections inside the box and every thing looked good. then I reset the breakers and turned the system back on, thats when I saw the arc inside the plug, so that made it really melty.

 

[augiedoggy]

First of all Id'd like to thank Pj and Kal for the help building my system and making it safe. But after 3 years, I have finally had a failure and it was not a big deal because of PJ and Kal.

Mid boil my circuit breaker pops and after a quick inspection I find the plug had over heated and melted. After swapping out the plug for a new one I was able the finish the brew. At the end of the brew I notice I can't turn off my kettle, I assume the SSR failed open and was giving the element 100% power and possibly resulting in the plug melting.

I'm thinking Im going to upgrade my wiring to the element from 10 gauge to 8 gauge wire.

Thought Id share.

View attachment 242184

View attachment 242185

View attachment 242186

I'm sorry but this was linked in another thread about suggesting pulling your control panel apart and checking these connections on a regular basis.
I dont mean to offend anyone but the failure here is clearly the way this was assembled.... I have seen this and done it myself with the similar results. that stripped wire is not long enough and is mangled up very badly which suggests it was not twisted and cleanly installed into the outlets clamping slot to begin with (perhaps it was not fully open?)... I have dozens of electrical plugs going back to the 20s with screw type connectors inside them and they dont just melt or fall apart like this unless the connection was poor to begin with. in this case the wire is so mangled that only a small outer portion of the outer diameter wire made direct contact with the outlet terminal this increases resistance and causes melting and things to loosen up.
Please for your own safety dont wire up connections like this for higher current draw and expect them to be safe.
I know the op stated the wire was mangled up like that after it fell apart but its just not the case iven if he did not realize it. if it was you would see a lot more electrical failures from this outlets. poorly made connections like this heat up and fail over time. this is also the reason for the codes these have to meet when installed correctly.

 

[Bsquared]

augiedoggy,

Thanks for the insight, I'm going to go through my panel tomorrow and I'll check the connections. I might break out the solder gun and sure up the high amperage connections.

B^2

 

[trimixdiver1]

FYI there should be a strip gauge on most twist locks. I know Hubble has them. I know a torque screwdriver is not a common thing for 99% of people out there, but there are torque specs out there. When you are close to the max capacity of the conductor (current draw) it becomes more of an issue.

I know others don't agree but if that is extension cord wire you hacked off a prebuilt cord, don't use it. Use SO or SJ cable. It will work much better.

 

[Bsquared]

It's type SJT 10 gauge 3AWG, you think that Is sufficient?

 

[trimixdiver1]

It's type SJT 10 gauge 3AWG, you think that Is sufficient?

The wires looked shiny to me, SJT is just fine. I know you meant 3 conductor not gauge. Yea strip length and proper tightness of the wire and strain relief and you shouldn't have this issue as long as you stay at the 80% or so of its capacity.

 

[augiedoggy]

I actually used 12g soow one one element and sjoow on the other... I used switchcraft connectors and I actually monitored the temps on the first couple uses and found the cable does not even get warm... The cable is rated for 25amps and my elements draw 18.3 amps max. since may cables are only about 6ft each and the load is not considered a continuous load (I never run my elements at 100% power for longer than or even near 3 hrs so the 80% rule does not technically apply here)

 

[Bsquared]

Went through my system last night and replaced the two element controlling SSR's that failed open, most all of my 10AWG connections had loosened a bit, so I checked that the terminals were still tightly crimped to the wire and re-tightened the connections. I'll be checking these every other brew from now on.

 

[trimixdiver1]

Went through my system last night and replaced the two element controlling SSR's that failed open, most all of my 10AWG connections had loosened a bit, so I checked that the terminals were still tightly crimped to the wire and re-tightened the connections. I'll be checking these every other brew from now on.

You shouldn't have to. Are you using those cheap spade lugs with the yellow ferrel on them? If you are, what are you using to crimp them?

Your terminal blocks shouldn't be working loose. Can you take a pic of the terminal block? Is it rated for the current your drawing?