Breaker switch started flipping on my last brew

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jdudek

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I have a 120V/20A system i put together myself. It has worked well for probably 5 or 6 brews. Last brew, the breaker switch on my control box started tripping and shutting everything off. It would just do this at random, a few times during the ramp up to mash, a few times during the ramp up to boil. It also shut off during boil multiple times, with the power dialed at 85-90%. I can turn it back on after a few minutes, then it's fine for a while and then shuts off again (that was an annoying brew day)

the switch is rated 20Amps. I am using a 2250 element from brew hardware. Nominally, that should pull 2250/120=18.6A from my 20Amp outlet. The only other thing pulling current would have been the PID, which should be in the mA.

i measured the resistance of the element. 6.3-6.4 ohm. I measured the outlet output, came in at 124VAC. Now 124/6.3=19.7A is getting awefully close to 20A. But somehow this had not been an issue the last 5 times i brewed. I am aware others use this element on a 20A circuit and it seems that is what it is designed and marketed for.

Any thoughts on how to troubleshoot? Has the breaker switch become faulty? Or is this cutting it to close in terms of available power, but then what would be the point of selling this particular element?
 

myndflyte

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Can't breakers only handle like 80% of its rating? So in your case, 16 amps. So that's probably why you keep tripping it.
 

doug293cz

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Can't breakers only handle like 80% of its rating? So in your case, 16 amps. So that's probably why you keep tripping it.
Code limits "continuous" max load on a circuit to 80% of the breaker rating. Continuous is defined as more than 3-4 hours (don't know the exact time.) Most homebrew systems will not be operated in a way that puts them into the continuous classification.

The breaker is not supposed to trip at currents below its rating. Sounds like the breaker in question is getting close to failing, and should be replaced.

Brew on :mug:
 
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jdudek

jdudek

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Don't think that's it. a) how could it have possibly worked before, b) a breaker can handle it's rated load, the 80% recommendation is for continuous operation which a home brewery is not, c) if that was the case, all of the 15A commercial offerings out there would not work as they all pull more than 80% of 15A.
 
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jdudek

jdudek

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Doug beat me to this one...
I'm going to order a new breaker switch and see if it fixes it. A bit disappointing though... it's not like this switch has seen many hours of operations, would not expect failures this early.
 

day_trippr

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I have had old breakers (like 30 years or more) that once tripped suddenly became unreliable.
It's like they were on their way out anyway, but a nudge put them over the edge.
That said it'd be a good time to go through all your high current connections and make sure they're tight...

Cheers!
 

thefigure5

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I have a 120V/20A system i put together myself. It has worked well for probably 5 or 6 brews. Last brew, the breaker switch on my control box started tripping and shutting everything off. It would just do this at random, a few times during the ramp up to mash, a few times during the ramp up to boil. It also shut off during boil multiple times, with the power dialed at 85-90%. I can turn it back on after a few minutes, then it's fine for a while and then shuts off again (that was an annoying brew day)

the switch is rated 20Amps. I am using a 2250 element from brew hardware. Nominally, that should pull 2250/120=18.6A from my 20Amp outlet. The only other thing pulling current would have been the PID, which should be in the mA.

i measured the resistance of the element. 6.3-6.4 ohm. I measured the outlet output, came in at 124VAC. Now 124/6.3=19.7A is getting awefully close to 20A. But somehow this had not been an issue the last 5 times i brewed. I am aware others use this element on a 20A circuit and it seems that is what it is designed and marketed for.

Any thoughts on how to troubleshoot? Has the breaker switch become faulty? Or is this cutting it to close in terms of available power, but then what would be the point of selling this particular element?
Circuit breakers trip due to temperature. If the ambient temperature where the breaker is is increasing with the summer heat, that could have an effect. Maybe it's minor, but if your on the edge or if the breaker is not ideal, it could explain what you have observed. I recently had a breaker fail and the cause was a spider or other creature made a tiny nest such that when I turned the breaker off and then back on, the contacts wouldn't make contact.

With resistive elements like yours, I think the resistance goes up as they heat up. I briefly looked for a data sheet for HEATING ELEMENT, TC INTEGRATED 2250 WATT (120V), but didn't find one. If you can SAFELY measure the voltage relative to earth ground at the 120V outlet or closer to the element, you could see the voltage with no load, then when the heating element starts heating, then at some interval as the element is heating up. By doing this you could qualitatively see the effect of heat on the element's resistance. If the voltage starts at 124V then drops when the element starts heating, but then starts increasing, the resistance of the element is going up with temperature, and the current is actually dropping from the initial current when the element was cold. A variable is that the wires between the voltage source and where you are measuring are also heating up starting when the element starts heating, changing their resistance. This would tend to decrease the voltage where you are measuring because the resistance of conductors generally increase with temperature, which would partially counter the effect of the element's resistance on current flow if its resistance is also increasing.

I'm not sure any of this really helps the situation if the breaker keeps tripping or the new one trips also, but it might help understand what is going on.
 
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jdudek

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Thanks for your reply. Good points, also i did not measure outlet voltage under load, so probably another "error". However, it would seem that as resistance increases with temperature, the current would start falling, taking us further away from the trip point. I would expect heat would make the situation better not worst.
 

thefigure5

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Thanks for your reply. Good points, also i did not measure outlet voltage under load, so probably another "error". However, it would seem that as resistance increases with temperature, the current would start falling, taking us further away from the trip point. I would expect heat would make the situation better not worst.
I found something related to temperature affecting the rated current of a circuit breaker if it is not an electronic trip type of breaker. What the table shows is that below 104 F, a given circuit breaker can pass more than its current rating without tripping. Above 104 F, the trip level has to be de-rated to a lower value.

1594251940055.png
 

barada83

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So far it sounds like you are just too close to the amp rating.
A couple of points worth addressing, voltage is a pretty steady input. I’m not sure what measuring outlet voltage means in the example but the mains voltage to ground is going to be the same although measuring across the resistance of the circuit will be decreased Amperage is the amount of current that is allowed to flow through the circuit and that is the part that changes. A 20a circuit does not always supply 20a although the voltage is still the same. Check this out for more in depth EE Resistive heating explained in details .

The amperage part of your system is being tripped. You can measure voltage drop across a resistor, and indeed, resistance does increase with heat which in a steady state of voltage will drop amperage or power consumption. The best and definitive test would be an amp meter though. You need to know how much current you are actually drawing. Code is designed with an 80% continuous load calculation to provide heat management and fire prevention. Although the duty cycle of the heater is not going to qualify for a continuous operation, it is still too close. If I was wiring, I’d step up to a 30a circuit to allow for overhead. Most water heaters are in the 30-50a category from what I know. One thing going for you is no inrush current like a motor would have.

One last thing is to remember that low voltage circuit breakers typically operate on a thermal load so they are not instantaneous but more of a short term average and not terribly accurate as an amp meter. A slight deviation above The set point can be accommodated short term. A short circuit can potentially do a huge current short term until broken which is one of the reasons gfci is used in some circuits.
 

augiedoggy

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Circuit breakers trip due to temperature. If the ambient temperature where the breaker is is increasing with the summer heat, that could have an effect. Maybe it's minor, but if your on the edge or if the breaker is not ideal, it could explain what you have observed. I recently had a breaker fail and the cause was a spider or other creature made a tiny nest such that when I turned the breaker off and then back on, the contacts wouldn't make contact.

With resistive elements like yours, I think the resistance goes up as they heat up. I briefly looked for a data sheet for HEATING ELEMENT, TC INTEGRATED 2250 WATT (120V), but didn't find one. If you can SAFELY measure the voltage relative to earth ground at the 120V outlet or closer to the element, you could see the voltage with no load, then when the heating element starts heating, then at some interval as the element is heating up. By doing this you could qualitatively see the effect of heat on the element's resistance. If the voltage starts at 124V then drops when the element starts heating, but then starts increasing, the resistance of the element is going up with temperature, and the current is actually dropping from the initial current when the element was cold. A variable is that the wires between the voltage source and where you are measuring are also heating up starting when the element starts heating, changing their resistance. This would tend to decrease the voltage where you are measuring because the resistance of conductors generally increase with temperature, which would partially counter the effect of the element's resistance on current flow if its resistance is also increasing.

I'm not sure any of this really helps the situation if the breaker keeps tripping or the new one trips also, but it might help understand what is going on.
I was going to mention the heat as well... seen it myself a few times. the breaker is designed to trip if it reaches a certain temp.. I also had a 4500w ripple fail in such a way that it would cause the breaker to trip randomly when it got hot enough as well so dont rule out the element just yet either.
 
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jdudek

jdudek

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If I was wiring, I’d step up to a 30a circuit to allow for overhead.
I can see that would definitely fix things, though it would seem to make this particular heating element rather obsolete. If you're going to wire for 30Amps, then may as well make it a 220V circuit and use a 5500W element. Brewhardware sells it stating " This version of the TC element is 2250 watts at 120 volt. Pulling 18.75 amps, this is about the highest wattage you can run on a standard 20 amp circuit (with a little room for a pump) "

anyway, new switch on the way, we shall see. If it still trips, i may just make a move to 240V/30A
 

augiedoggy

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I also found that if the element becomes coated and scorched it can actually start tripping the breaker until its cleaned... found this out when experimenting with step mashing with rye and a new rims element.. The element overheating somehow changed its resistance I guess. once I cleaned it it was fine from then onward.
 

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Something that I haven't heard mention of is that I have seen a few cases of repeated CB trips that were "fixed" by replacing the breaker.(**) CB's, while are designed to trip for obvious reasons they don't like to be, nor should they be used as a load bearing switch. I have replaced 20A breakers that would not hold 14A after multiple trips. YMMV.

(**) After the cause of the original trip was found. (ie, short/overload)

Joel B.
 
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jdudek

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Something that I haven't heard mention of is that I have seen a few cases of repeated CB trips that were "fixed" by replacing the breaker.(**) CB's, while are designed to trip for obvious reasons they don't like to be, nor should they be used as a load bearing switch. I have replaced 20A breakers that would not hold 14A after multiple trips. YMMV.

(**) After the cause of the original trip was found. (ie, short/overload)

Joel B.
interesting... what i have is used as an on off switch, not exclusively as a breaker. It is not a panel breaker however, just one of these from Auber. They use it in their own controller as a power switch, so I figured it must be a safe application. But indeed, i "trip" it intentionally all the time.
 

Ihop2many

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I have a 120V/20A system i put together myself. It has worked well for probably 5 or 6 brews. Last brew, the breaker switch on my control box started tripping and shutting everything off. It would just do this at random, a few times during the ramp up to mash, a few times during the ramp up to boil. It also shut off during boil multiple times, with the power dialed at 85-90%. I can turn it back on after a few minutes, then it's fine for a while and then shuts off again (that was an annoying brew day)
As if brewing wasn't difficult enough without adding random incidents to your day!

I have experienced the same challenge and although it is pertinent to replace breakers that are older or have been tripped many times this was not the cause in my case.

Disconnect the AC power and measure the dc resistance of the element between any end and ground. It should read infinity, or at a minimum very high resistance (above 50k ohms), if it reads low then you have a bad element. I had two 4500W elements where the insulating material had deteriorated after about 5 or 6 brews and became low resistance after the element heated up, causing the GFCI breaker to trip.

If you discover this is the case then you'll need to change the element.

Electro magnetic breakers are not subject to ambient temperature issues and would be the ideal replacement if compatible with your breaker panel.

All the best
 

Tobor_8thMan

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Circuit breakers trip due to temperature. If the ambient temperature where the breaker is is increasing with the summer heat, that could have an effect. Maybe it's minor, but if your on the edge or if the breaker is not ideal, it could explain what you have observed. I recently had a breaker fail and the cause was a spider or other creature made a tiny nest such that when I turned the breaker off and then back on, the contacts wouldn't make contact.
Most interesting and I didn't know especially considering years involved in other hobbies/licenses, etc. I learned something new today. Thanks!
 

Tobor_8thMan

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I also found that if the element becomes coated and scorched it can actually start tripping the breaker until its cleaned... found this out when experimenting with step mashing with rye and a new rims element.. The element overheating somehow changed its resistance I guess. once I cleaned it it was fine from then onward.
Perhaps increased resistance due to the scorching?
 
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jdudek

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increased resistance = less current. Anything that increase resistance cannot manifest itself as a tripping breaker, all else being equal. If the breaker is good and is tripping, then something is pulling more current, therefore the equivalent resistance of the circuit must have decreased.
 
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jdudek

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Disconnect the AC power and measure the dc resistance of the element between any end and ground. It should read infinity, or at a minimum very high resistance (above 50k ohms), if it reads low then you have a bad element. I had two 4500W elements where the insulating material had deteriorated after about 5 or 6 brews and became low resistance after the element heated up, causing the GFCI breaker to trip.
I don't think this switch is GFCI... it's just a power switch on the controller with added overcurrent protection. What you describe would be a path to ground that would make the GFCI outlet reset I think. Or am i misunderstanding?
 

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The 99% likely answer is that its the ultra cheap chinese made circuit breaker. The element is a big dumb resistor. The breaker is made of thermally reactive bimetal components with a precise calibration requirement.
 

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increased resistance = less current. Anything that increase resistance cannot manifest itself as a tripping breaker, all else being equal. If the breaker is good and is tripping, then something is pulling more current, therefore the equivalent resistance of the circuit must have decreased.
What ever it was in my case, once I cleaned the element surface (which was no easy feat) the issue went away...It was not the main gfci breakers but rather one of the individual din breakers in my control panel. It was a brand new triclamp based 6000w element from brewmation and I was pretty upset with myself at the time. I had the max power output set to 70% effectively bringing the watt density down loawer than the ULWD rating it had but still the geletinization of the rye from stepping from 120 degrees up was just too thick regarless. Havent had and issue yet since but I no longer step mash the rye that way.
 

Bobby_M

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Its counterintuitive because resistance of various heating wires like nichrome goes UP as temp increases. If residue trapped a lot of heat, the total current draw should reduce slightly.
 

augiedoggy

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Ive heard of breakers
Its counterintuitive because resistance of various heating wires like nichrome goes UP as temp increases. If residue trapped a lot of heat, the total current draw should reduce slightly.
I dont have an answer but I know I seen a report of someone having a simiar issue on an all in one urn setup when the element area was full of grain.
 

Vale71

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What ever it was in my case, once I cleaned the element surface (which was no easy feat) the issue went away...It was not the main gfci breakers but rather one of the individual din breakers in my control panel. It was a brand new triclamp based 6000w element from brewmation and I was pretty upset with myself at the time. I had the max power output set to 70% effectively bringing the watt density down loawer than the ULWD rating it had but still the geletinization of the rye from stepping from 120 degrees up was just too thick regarless. Havent had and issue yet since but I no longer step mash the rye that way.
The ony explanation I could think of is that the scorching dampened heat transfer so much that the element overheated and this somehow caused a temporay short to ground overloading the circuit and causing the breaker to trip. Maybe the insulation that keeps the actual resistive element from touching the outside stainless sleeve looses its insulating properties beyond a certain temperature causing a short to ground and the load breaker tripped before the GFCI could trip?
Otherwise as others have said overheating would only cause resistance to increase and current to drop, which is true of any simple conducting material. To reverse this relationship you need solid state components such as is the case with NTC probes.
 

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You're probably onto something there. The resistive core in an element is kept away from the grounded outside sheath with a hard pack of ceramic powder. Then the sheath is heated up red hot and bent into whatever shape it's going to be. The QC process involves testing the core's resistance to ground cold, and after a few heat cycles. As long as it's not shorting, it passes. There is no telling how small of a gap there is between the two conductors at any given spot along the run but it could be paper thin. One odd heat cycle can conceivably get them to touch. That's why I'm a little freaked out when folks intentionally dry fire the elements to clean them
 
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