Electricians needed

[nate85]

I have a bit of an issue. Some background first. I've build 2 Pid smokers and am now working on the 3rd for my cousin. One was 120v 1500 watts and the other was 240v at 4600 watts. They run great no problems at all. He went big so here is what I did, 1 pid, a disturbution block, 3 25amp SSR(one for each burner), 3 2600 watt burners, used 10 gauge high temp oven wire inside the box all the way to the relays and block. The problem- He lined his smoker box with stainless, when I touch the metal I can feel a current like its energized when the pid is putting power to the burners. I've checked all my wiring and none are bare or cut. He does have the burners mounted to an angle that is mounted to the stainless, but I don't see any issues with it( mine are mounted the same) the wires are all coming through 1- 1" hole and are bundled along the angle till they reach each burner. Is them bundled the problem? Should I have a ground run to the inside of the box? Any help or suggestion would be appreciated

 

[ironhorse07]

yes, You should absolutely have an equipment ground.

 

[nate85]

I am grounded to my junction boxes and stuff on the outside but not the inside of the smoker

 

[ironhorse07]

Are your SSR's bonded to the chassis ground also? Some pics of what your setup looks like would help.

 

[nate85]

Itll be this weekend till I can get pictures. No they are mounted to heat sinks which are mounted to OSB. I'm thinking it has to do with the wires or the burners in the box itself as everything else seams ok and works properly. Where the wires hook to the burners, they are crimped to ring terminals then bolted on. I'm wondering if I need to get something over them as there bare but not touching any other metal

 

[johnmeyer]

The first thing I'd do is make sure it is plugged into a GFI outlet. Test the GFI before you proceed.

Next, before plugging it in, clip your multimeter, set to the Ohm mode, onto the metal enclosure. Then, probe all three prongs of the power plug with the ohmmeter set to the most sensitive range. You should get infinite continuity.

If you don't measure any leakage resistance, then the current you felt is being induced by some sort of AC coupling. It is actually quite common to have no leakage, when measured with a low-voltage ohmmeter, but still have leakage when powered with the much higher voltage (120V) coming from the power plug, and when powered with AC instead of DC. Alternating current can couple electricity across an insulator via magnetism. This is how transformers work.

Now for the powered test.

Connect one lead of the meter to the metal case of an outdoor junction box which, presumably, is grounded. Set the meter to AC Volts, and set the range to something above 120V. Turn on the smoker, and with one hand in your pocket, with the smoker connected to a GFI outlet, and while wearing rubber shoes, touch the probe to the metal interior and see what sort of voltage you measure.

The final step would be to measure the leakage current, but that is too tricky to describe.

 

[ironhorse07]

The first thing I'd do is make sure it is plugged into a GFI outlet. Test the GFI before you proceed.

Next, before plugging it in, clip your multimeter, set to the Ohm mode, onto the metal enclosure. Then, probe all three prongs of the power plug with the ohmmeter set to the most sensitive range. You should get infinite continuity.
You should get continuity from the ground prong to the chassis though, correct?

If you don't measure any leakage resistance, then the current you felt is being induced by some sort of AC coupling. It is actually quite common to have no leakage, when measured with a low-voltage ohmmeter, but still have leakage when powered with the much higher voltage (120V) coming from the power plug, and when powered with AC instead of DC. Alternating current can couple electricity across an insulator via magnetism. This is how transformers work.

Now for the powered test.

Connect one lead of the meter to the metal case of an outdoor junction box which, presumably, is grounded. Set the meter to AC Volts, and set the range to something above 120V. Turn on the smoker, and with one hand in your pocket, with the smoker connected to a GFI outlet, and while wearing rubber shoes, touch the probe to the metal interior and see what sort of voltage you measure.
LOL, one of the first things I was taught about working with electricity. Haven't heard that in awhile.

The final step would be to measure the leakage current, but that is too tricky to describe.

 

[nate85]

The first thing I'd do is make sure it is plugged into a GFI outlet. Test the GFI before you proceed.
This isn't a plug in type, it's all hard wired, we are going with a GF breaker after final testing is done and it's to its final location


Next, before plugging it in, clip your multimeter, set to the Ohm mode, onto the metal enclosure. Then, probe all three prongs of the power plug with the ohmmeter set to the most sensitive range. You should get infinite continuity.
There isn't a plug, I take it unhook the wires from the SSR side that go to the burner and test?

If you don't measure any leakage resistance, then the current you felt is being induced by some sort of AC coupling. It is actually quite common to have no leakage, when measured with a low-voltage ohmmeter, but still have leakage when powered with the much higher voltage (120V) coming from the power plug, and when powered with AC instead of DC. Alternating current can couple electricity across an insulator via magnetism. This is how transformers work.
If this is the case what's my best bet to fix it? Separate the wires or is there a high heat insulation wrap that I can better insulate the wires with?

Now for the powered test.

Connect one lead of the meter to the metal case of an outdoor junction box which, presumably, is grounded. Set the meter to AC Volts, and set the range to something above 120V. Turn on the smoker, and with one hand in your pocket, with the smoker connected to a GFI outlet, and while wearing rubber shoes, touch the probe to the metal interior and see what sort of voltage you measure.

The final step would be to measure the leakage current, but that is too tricky to describe.

If it's none of the above I'll be having an electrician come out and look at it. I have one built just like this but it's only two burners and I've never had trouble with it. Thank you for all the advice

 

[johnmeyer]

Whether or not you get continuity from the ground plug to the metal interior depends on the design. The fact that the OP felt electricity when touching the metal interior makes it sound as though it is not grounded. What's more, grounding that metal interior may, or may not, be the right thing to do, depending on how everything else is connected.

 

[nate85]

Here is what I did, power supply comes from the disconnect, neutral is bugged off, red and black to the 2 circuit power distribution block, ground goes to my junction box and the metal I used to mount the PID. From there I pulled one wire for each burner from the block to the burner, then did the same from the block to one side of each relay, then from the other side of the relay to the other side of the burner. And of coarse the 12 volt wiring from the pid to a junction box then onto each relay. Sorry for the crappy pic. I'll get pictures of the burners maybe tonight. All wires from the block to the relays and burners are 10 gauge high heat wire, connections to the burners use ring terminals crimped on and then bolted through the eyes with brass bolts and nuts.