My Circuit Breaker Keeps Tripping: Why?

[Walker]

I'm very interested to find the culprit of this... I don't know enough or can interpret enough to find a problem with your wiring, except that there is no circuit protection for anything except for your 50 amp breaker. Perhaps there was some surge and something melted? That would cause a trip as described. Sorry if I sound like a noob but this really stood out as I checked your photos. Some of those components can't take as much current as is available to them.

Good point. All of the wiring and switches should be rated to handle 50A to be "up to code" since you don't have any fuses or small breakers protecting the stuff.

Something to think about if you want to make sure you don't fry anything and/or start a fire.

 

[bf514921]

Minor thing, the nuetral bar, the incoming nuetral for main should be wired to the lug below, not in the nuetral bar, dont think it will matter in resolving the issue.

is the source 4 wire? When testing the contactor, was the ssr also on?

 

[TheAleMaster]

Well, that would possibly explain why both breakers would trip if there was a ground fault. (are you sure the main breaker was on when you did this test of the GFI?)

Yes, I had the control panel on when I hit the test button.

How does the ground wire get into the box? Your spa panel looks like it is only handling the two hots and neutral, but four wires are coming into the box.

It's there. It is attached under the cabling for the lines out.

I've read this paragraph a couple of times, but I'm not sure I understand it. Why are there four connections on the switch? Is it illuminated or something and you are feeding the switched voltage back through it to get it to light up?

Correct. Sorry I didn't mention the light on the switch.

What are the other things on the lid?

Obviously the PID and next to the PID is a .25 amp fuse. The SPST switch is for the 120v outlet that I have in the box. The DPST switch is to turn off signal to the SSR when I have the element off, but the PID still on.

Good point. All of the wiring and switches should be rated to handle 50A to be "up to code" since you don't have any fuses or small breakers protecting the stuff.

Something to think about if you want to make sure you don't fry anything and/or start a fire.

As mentioned, I do have a fuse on the PID. Where would be other places to put fuses to adequately protect? Would it be better to just put a 30 amp breaker in the service panel and use the 50 amp GFI solely for GFI protection?

Minor thing, the nuetral bar, the incoming nuetral for main should be wired to the lug below, not in the nuetral bar, dont think it will matter in resolving the issue.

Which lug? Aren't those lugs on the hot bar? It was my understanding that you need to have your incoming neutral attached to the neutral for the GFI breaker.

is the source 4 wire? When testing the contactor, was the ssr also on?

Yes. 4 wire source and everything is on (and every combination of off and on).

 

[Walker]

Ok. I see the ground now and understand the other items on the lid.

As mentioned, I do have a fuse on the PID. Where would be other places to put fuses to adequately protect? Would it be better to just put a 30 amp breaker in the service panel and use the 50 amp GFI solely for GFI protection?

Well... any place where you want to drop down in wiring size or prevent a device that is meant for lower current than is allowed to come in.... it is a good idea to have circuit protection. You've got items rated for 50A all the way from the main panel to the power distribution block in the box, but then you drop down in wire gauge and have that attached to components that cannot handle 50A. If something causes a short and 50A comes pouring into the box, those smaller wires could melt, or your SSR could die from the excessive current being pumped through it, or something like that. Components are at risk.

In my box, a 50A GFI breaker in the panel drives 50A rated wire that goes to a 50A rated receptacle and plug. The plug is on a cable rated for 65A, which goes into the box and hits a power distribution block rated for 60A.

So far so good. Everything downstream of the breaker is rated for same or more current the breaker will allow through.

From the power distribution block the only place the hots go is to some small panel-mount circuit breakers. One hot goes to a 25A breaker and nowhere else. The other hot goes to a 25A breaker as well as a 15A breaker and nowhere else. All of the actual electronics are then attached to the output side of these protecting breakers.

Those two 25A breakers mark the start of my 240V heating element power path. Everything on that 240V path is rated for 25A or more; #10 THHN wiring, 30A contactor, 40A SSR, 30A receptacle, 30A plug, and 30A cable out to the element).

The 15A breaker marks the start of my 120V path. This is pretty much a power path that looks like your average home outlet. 15A/120V GFI protected via the big breaker in the panel. I drive my 120V devices from this power path (control switches, PID, pulse modulator, pump.)

So, to protect that smaller wiring that goes to your contactor, PID, SSR, etc, you should have a fuse or breaker there that is rated for what the items can handle.

EDIT: forgot to finish my thoughts. You could put 30A in the panel and use the 50A just for GFCI protection. That's certainly an option.

 

[Walker]

One more comment.

It looks like the smaller wiring in your box is 12 gauge. Is that right?

Is that rated for 30A?

I hate this particular question, because different references claim different things and I don't know how to determine what is right.

these claim 20A:
http://www.cerrowire.com/default.aspx?id=46
http://www.encorewire.com/docs/amp voltage.pdf

Wikipedia claims 25A:
http://en.wikipedia.org/wiki/American_wire_gauge

This claims 41A in one table and 20A in another:
http://wiki.xtronics.com/index.php/Wire-Gauge_Ampacity

When deciding my wiring, I went with the most pessimistic table and use that size wiring (which lead me to 10 gauge wiring for a 25A load)... I figure I have my bases covered that way.

 

[TheAleMaster]

Okay. Do you have a pic of your panel? Where could I get some breakers that I could panel mount (or mount inside the box)? Would it be easier to just pick up a few fuses from my local hardware store?

I'm thinking I need protection in front of the hots for the contactor (which would in turn protect the SSR), the hot to the switch for the contactor, and the hot to my 120v.

Back to my original dilemma, do you think it is possible to solve what happened? Or should I just build a new element assembly, protect my components, and give it another go?

 

[TheAleMaster]

Yeah, it is 12. I went off the chart at Home Depot. Maybe I'll just rewire with 10. Then fuse for 30 on the contactor/contactor switch (both are rated for 40a as is my SSR following the contactor) and then fuse for 15 on my 120v circuit.

 

[Walker]

Okay. Do you have a pic of your panel?

Yeah, let me find one and I'll post it. I have a scematic somewhere, which might be easier to read, though.

Where could I get some breakers that I could panel mount (or mount inside the box)? Would it be easier to just pick up a few fuses from my local hardware store?

Fuses might be easier/faster to obtain, but more expensive in the long run. If a fuse blows, you have to replace the fuse. If a breaker trips, you just reset it. I bought small panel-mount circuit breakers and most of my other electronics from mouser.com. Here's the ones I am using:

15A breaker: http://www.mouser.com/Search/Produc...-15virtualkey69300000virtualkey693-T9-611P-15
25A breaker: http://www.mouser.com/Search/Produc...rtualkey65500000virtualkey655-W54-XB1A4A10-25

There are lots of other ratings, 2-pole versions, etc, etc. Mouser.com has a TON of stuff and the prices are pretty good.

I'm thinking I need protection in front of the hots for the contactor (which would in turn protect the SSR), the hot to the switch for the contactor, and the hot to my 120v.

Yeah, I'd suggest breakers between the contactor and the power distribution to protect the power path going to the element via the contactor and SSR.

For the 120V stuff.... you already have a 15A fuse protecting the PID. You could tap ALL of your 120V power off that thing, couldn't you? That's basically what I did.... the hot from the distribution goes to a 15A breaker (or fuse, in your case), and then everything that is powered by 120V feeds from there.

Back to my original dilemma, do you think it is possible to solve what happened? Or should I just build a new element assembly, protect my components, and give it another go?

I don't know if we'll solve it or not. I'd add protection and get a new element and get the show back on the road.

 

[Walker]

These pics are from when I was testing connectins and switches and whatnot only 120V feeding in (no heater element attached), so they don't show the fat 65A cable coming in with proper input to the power distribution, but they show most of the other wiring.

Inside the box:


Ignore the left side of the power distribution (it's jimmy rigged for 120V), but on the right side where wires come out....

hots go down to 25A breakers on bottom right corner of box, those feed to the contactor, and then one hot goes to the receptacle while the other goes to the SSR above before coming down to the receptacle. (you can see the reset buttons for the 25A breakers when you look at the back of the box):


Back inside the box.... Neutral from the power distribution goes to a few places; one is the 120V receptacle there for my wort pump, another is to the left to the hinged door of my box for my control devices, and then there is a connection to the contactor right there (hot for the contactor comes from a switch on the door).

There is a black hot that comes out of the distro block and goes toward the door (to the 15A breaker mounted there).

Here's the door... it's a bit of a rat's nest because I have a 6 pin selector switch right in the freaking middle that allows me to select whether the PID (on the right) or the pulse width modulator (on the left) is in control of the SSR.



The important part is that the main power feed from the distribution block attaches to the 15A breaker (center/bottom) before going up and connecting to everything else (PID, PWM, switches, etc).

Here's the front to help understand what the items are:


Starting at the top center and going clockwise:
- green switch that turns on pump receptacle in the box.
- orange indicator lamp that lets me know power is making it to element.
- knob and LED for pulse width modulator (for manual control of kettle)
- red switch that activates the contactor and lets the 240V through
- 15A breaker protecting all 120V items
- green switch that turns on PID (It's function will change when I upgrade the system later, but I wanted to get the freaking hole cut in the steel and be done, so I decided to use the switch for SOMETHING)
- PID (with no probe connected and reading 'EEEE')
- the other square switch in the center (above the 15A breaker) is the switch that selects PID or PWM as the controller of the SSR.

 

[TheAleMaster]

I have a 1a (maybe going down to a 0.25a) fuse protecting the PID because the power draw is so low and I don't want it fried.

So I think I will get two 30a breakers from Mouser for the two hots going to the contactor, a 10a for the contactor switch (that's what Automation Direct recommended), and a 15a for my 120v outlet.

 

[TheAleMaster]

Nice job on the control panel. Mine's not quite that complex because I am only doing a BK - no HERMS or RIMS.

 

[Walker]

I have a 1a (maybe going down to a 0.25a) fuse protecting the PID because the power draw is so low and I don't want it fried.

Ah... for some reason, I thought you mentioned that it was 15A earlier, but I see that you said 0.25A.

I probably should put a fuse on mine, too.

So I think I will get two 30a breakers from Mouser for the two hots going to the contactor, a 10a for the contactor switch (that's what Automation Direct recommended), and a 15a for my 120v outlet.

Interesting.... my contactor only draws 0.5A. A 10A breaker seems pretty darn large for that use.

At any rate, I didn't want a zillion breakers all over the place, so I opted to protect all of the 120V stuff with a single 15A breaker. I will probably add an in-line fuse to protect the PID since it cost a little under $40, but the contactor was only $8 and the pulse modulator only $3 or so, so I'll take my chances.

 

[Walker]

Nice job on the control panel. Mine's not quite that complex because I am only doing a BK - no HERMS or RIMS.

Thanks. I've left the left side of the box free of components, because I plan to later add a dedicated HLT for the HERMS instead of making the BK serve double duty. That'll add another set of little breakers, contactor, SSR and receptacle. The selector switch will then be retired. The PID will then control the HLT and the $3 modulator will control the kettle.

 

[TheAleMaster]

I'm sure my contactor doesn't draw much, but the recommendation for the illuminated switch was 10a and it is obviously inline with the contactor. I have a lot of real estate on my panel cover, so maybe a few breaker switches will enhance the bling factor.

 

[Walker]

I'm sure my contactor doesn't draw much, but the recommendation for the illuminated switch was 10a and it is obviously inline with the contactor.

That just means that the switch can handle 10A before it dies. You don't need to have a 10A breaker in front of it. You can go much smaller.

I have a lot of real estate on my panel cover, so maybe a few breaker switches will enhance the bling factor.

That's true.

One thing you might find at mouser is that you can get breakers that are controlled by illuminated rocker switches, so you could actually REPLACE your current contactor power switch with a combo switch+breaker item.

I thought about that at one point, but decided that the little "push-to-reset" breakers would be better for me. I have no way of manually turning those breakers off. I can only turn them back on if they pop.

 

[TheAleMaster]

I ended up doing the Push to Reset for the 30a because they didn't have the rockers. But did the rockers for the others.

 

[bf514921]

heres the way mine is wired, lookes like you have the same spa panel from home despot.

if you look close the incoming nuetral is wired to the middle lug