I need help on why my breakers on my Ballisticast mark 2 keep tripping.

[odfairfaxsub]

Reducing voltage across a element does not increase amperage as if you were figuring

I=W/V

Think about a light bulb on a resistor almost. The resistor decreases voltage however as you increase your resistance you decrease voltage causing your bulbs to create less lumens of light.

Decreasing voltage improves life of a element but may cause your run time to melt increased.

Do not use the amps equals watts divided by volts to figure out your amp draw

[odfairfaxsub]

I would choose however to maybe run your formula as

Volts divides by ohms equals amperage

[BamaNapper]

Yes, watts (power) divided by voltage is amperage. Plug a 1000 watt toaster into a 120V outlet and grab that hand-dandy clamp on ammeter. It's going to read about 8 amps. Trying to figure out the resistance of that 1000 watt toaster is a bit more difficult. But it's because you're picking up an ohmmeter that uses a small DC voltage to determine resistance. Plug that same oven into the wall and you're using big AC voltages. With DC you measure resistance. With AC you need to calculate reactance, where resistance is just one of three components.

Simple examples. Measure a capacitor with your ohmmeter and it's millions of ohms. You should be safe putting those millions of ohms across 120V. But if you try it there's a good chance you're going to pop the breaker or blow up the capacitor. On the other hand, measure across a transformer and you have about 5 ohms. That means you should see 24 amps if you plug it in. But you plug it in and the ammeter says it's pulling less than .1 amps. The whole resistance thing falls apart with AC circuits. Technically, once an analysis is done a device may be said to appear as a 16.6 ohm load at 2-phase 60 Hz. While that may be what an engineer is looking for, the rest of us understand it easier if they simply call it a 2600W heater.

My point is that a heating element rated for 2600 watts is going to pull 12.5 amps from a 2-phase connection, regardless of all the ohms you've measured or calculated. The power rating of a furnace (in watts) divided by the design operating voltage (2-phase 120VAC = 208VAC) will give you the AC current draw when stable. As I mentioned earlier, there may be an in-rush current that is much larger than the operating current when the device is first powered on. It gets mind twisting if you really get into the weeds with this stuff. Also, rember that current (amperage) in an AC circuit changes the same way the voltage does, 60 times a second.

[Mike W1]

I've really forgotten over the years probably most of what I learned in school. Somehow can't put my mind about having #14 on anything but a light bulb circuit and certainly not a 220v setup. My pots are on #12 with 20amp breakers all of about 3 feet from the main box. And my pots are Lee 10 pounders at about 500 watts! Each has it's own circuit.

Had a problem with my air compressor sometimes kicking a breaker in the garage and my brother enlightened me to the fact that the 99¢ receptacles are 15 amp and the better ones are 20. Just that took care of that problem for then as the wire was #12.. The next spring I ran a #10 across the garage. Used the Same 20 amp breaker on that.

Somebody above had mentioned feeling the wire for heat. I've often thought some appliances use some marginally sized cords. The electric broom in our kitchen does that but I've never had that upgraded. Wires are all #12 with the better receptacles too.

[BamaNapper]

You've got a handle on it Mike. 15A = 14 AWG; 20A = 12 AWG; 30A = 10 AWG. When in doubt, you can oversize the wire, oversize the receptacle, and undersize the breaker.

[TonyN]

No. I'm talking about the breakers on the machine. They where 15 amp and I put 20 amp in there place. I talked to one of the Mods on this site the beginning of this summer and told me I could go from 15 amp to 20 amp. I actually bought the machine from a guy on this group. He wasnt sure why it would trip as he didn't have that problem much. He thought they whe older and needed replaced soon. Hatch is the mods name. Just came to my head... Hatch helped the guy I bought it from re wire the machine. I ended up asking Hatch about the breakers tripping and he told me to go with the 20 AMP. It's weird is that the one that was tripping before I took out before and ended up putting back in and it's not tripping as much. Like I said before. Its a off and on thing.

[odfairfaxsub]

The Watts is a engineered idea that I can provide said amount of watts if all conditions are correct. Easiest thing to do really is check your hot leg amperage w a clip on but watts isn’t necessarily a good way to do ohms law. Elements degrade, manufacture material is changed, who knows. Watts is only a idea that was engineered in a lab once apon a time. There’s no sure way to know if you are actually using a “3000 watts.”

[BamaNapper]

TonyN, I have obviously never dealt with the BallistiCast. I got to thinking about your issue last night, hit up YouTube, and thought I'd pop back on with a couple more thoughts.

Your machine appears to have 3 motors, the timing solenoid, and a heating element. I assume the motors are 120V, but the motor in the bottom may be 2 phase, 208V. The heating element is certainly going to be 2 phase. the power into the machine is 2 phase and you're tripping both breakers intermittently. Maybe tripping one more often than the other, but both will trip at times. If I'm understanding correctly so far, then there are assumptions we can make.

The power path for the heating element is through one breaker, through the SSR controlled by the PID, through the element, then back through the other breaker. That means both breakers are carrying the same heater current. For the blower motors, each would only be using one breaker and the neutral. Both motors may be using the same breaker, I can't tell that from YouTube videos and the info I've found online. First conclusion, assuming blower motors are 120V, if one of the blower motors had a short or a bad cap in it, it would only trip one breaker. I think it's a safe assumption that if both breakers are tripping because of the motors you'd be looking at both motors failing in the same manner. The odds are really slim of that.

So my assumption is that it's a 2-phase component that's the problem, and that it's actually drawing about 20A at times. Since the same current for 2-phase motors or heaters has to travel through both breakers, when that current gets high enough it's going to trip the weaker of the two breakers first. One might be a tad weaker and trip more often, but either may trip. The temperature of the breaker is important and either may be warmer. More on that in a bit.

The next clue is that you were running the machine with 15A breakers installed. If it was running with 15A and tripping intermittently, then running with 20A and tripping intermittently, it doesn't sound like something is just slowly going bad. An aging element that is starting to draw enough current to trip a 20A would probably have been tripping a 15A immediately. So I assume your heating element is running along at the expected 12-13A and then jumps over 30A for one reason or another. It could be shorting internally. Or as I replied earlier, maybe it's cycling on/off too quickly.

What if the motor in the bottom is 2 phase? That could also be the culprit. A shorted winding in a 2 phase motor would give you the same tripping breakers as a shorted element, dropping the weaker of the two breakers. If the motor was always drawing a ton of current where it would represent a significant portion of the load, the motor would be very hot. 20A at 208V means 4000+ watts need to be going somewhere. A small motor consuming 2000W is going to melt down in a hurry.

Can you run the furnace without the motors and still trip the breakers? That would isolate it to the element and/or PID.

Since this is a furnace, is there some kind of thermal barrier between the molten lead and the breakers? Most breakers work by excess current heating up the trip mechanism. If you blow hot enough air on a breaker long enough, it will trip regardless of the current. Can the panel holding the breakers be hung free where you can move some air across them? The breakers are sealed so the moving air isn't going to affect their current rating. Most breakers have a temperature rating on them (40C or 100F is typical). If it's mounted in a panel bolted to a pot of molten lead, you may be well above that. Again, I'm not familiar with the machine. I wouldn't be surprised to find out this is the issue. It makes sense. It explains why both the 15 and 20A breakers would act similarly. Actually, I like this one the best.

As far as bad connections, they get a bad rap. Normally a bad connection is loose and corroded, resulting in less current draw, not more. Yes a bad connection on a motor can cause it to start more slowly or slow down and drop the start cap back into play, thus spiking the current. But typically a bad connection is going to show up as burnt insulation on the wire next to it, or discoloration of the terminal or screws. I don't recall ever seeing a bad connection tripping a breaker and I've been working with electrical/electronics for more than 40 yrs.

A clamp on ammeter would be useful. Harbor Freight, $14. You can also get cheap little panel mount ammeters from Amazon that have a toroid you just have to run one of the power wires through. A couple of those mounted at your breakers would let you keep an eye on the current while everything is running. I think they are $10-15 each.

Enough of a rambling. Good luck sir.

[TonyN]

Thanks all.

Sometimes the breaker will trip when the pot is warming up. But mostly when the machine has been running for a while. The breaker get a little warm but not hot.
Like I said sometimes it will go for couple hours then trip once or twice. The one that has been tripping is for the pot I believe. When it trips the PID start to loose temp and they start to cool down.

[BamaNapper]

If you had a schematic for the unit this would be much easier. You mention that the breaker tripping is the one for the pot. The pot almost certainly uses 2 breakers, and I would hope they're ganged. If the pot is only one breaker, the math says that's 2600/120=22 amps. If there's only one 20A breaker it's gonna trip. And typically a PID is powered from the same leg as the load it's controlling. All my assumptions on how this beast is wired are out the window.

[smoked turkey]

Tony I have read most of the posts up to the end. Some I just skimmed over. I think you have received some good electrical advice from a lot of folks here. Fact is that without a schematic or a wiring diagram we are all just shooting in the dark. First and foremost, your nameplate has the specifications of the machine. It specifies a 240 volt connection, 30 amp circuit. Your breakers are trying to tell you something I think. They are your safety net. As one poster mentioned, breakers do go bad sometimes with their inner springs becoming weak due to excessive heat and just plain old wear and tear. But you have changed the breakers in the machine. I do not think upping the amperage on a breaker is addressing the problem and in fact may cause additional problems. I think we have to assume that the machine used to function fine with 15 amp breakers. I believe your machine should have come with a 2 pole, 240 volt, 30 amp circuit breaker. At any rate you didn't mention it but your panel breaker has never tripped. It has always been the breakers internal to your machine. Apparently the main heating element is 2600 watts. Based on that your machine should pull 2600/240=10.8 amperes. Your specifications list another two 150 watt elements. If they are each 240 volts also then the current draw from those are 300/240=1.25 amps. You are also running two heavy duty shaded pole blowers. We know nothing about the current draw on those. There is a drive system, a PID, and other electronics. We know nothing about those either. Lets be basic here and say the machine should have a single cord rated for 30 amperes and plug into a 30 ampere, 240 volt circuit wired with #10 AWG copper. A tong ammeter would help immensely here as it would let you know the current draw. You need to know the total current draw at full load. Apparently the units auxiliary electrical loads cycles on and off and your problem occurs when all the load comes on at the same instant. My take on it is that it is a complex unit with control circuitry that runs it all and there are many variables that come into play making trouble shooting it difficult. Especially on the world wide web. I would be careful in changing breakers and jumping to conclusions. You need someone who can look at the diagram and make measurements on site.