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Mustang

Please help I am getting strange reading of electricity in my Tanks

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Ok so here is where i am literally.
So about a week ago i tested for electricity in my tank. I had and auto clamp tester with leads and a cheep analog tester. I was getting strange results and consulted RC and then Marc who reminded me of his article he did some time ago. http://www.reefaddicts.com/content.p...ay-Electricity Using his article as my guide i set out to test again and decided to get a tester similar to the one he used to help eliminate human error.
So here are my strange results. I hope someone can make sense of them.
1. I do not get a shock from any of my tanks when i work on them. When working on 108gal sump i am usually bare foot on cement floor.
2. Did feel a sting a few times when working in the sump of the 108gal where i had a small cut. Not sure if this was the salt stinging or electricity.
3. 108gal readings

Nothing pluged in 7.5-8.4 volts
Skimmer 18.8v
return pump 4.6 ( because it is less then when i had nothing plugged in)
Heater in middle sump chamber 31.6v
Heater in return section 25.1v
Heater tank 17.5v
Aqua lifter pump 9.5v
lights glo t5 ho suspended not touching tank maybe .5v each x3
Power head 1 18.9
Power head 2 18.7-19.1v

With everything plugged in i get 18.2v
Test was done with red lead in sump and black in ground in the outlet.

I have 2 30gal fresh water tanks that have AC 70 and heaters. Here are there results
1. Nothing plugged in i get about 6v
2. Aqua clear 16volts
3. Heater and AC i get about 30v

SW 12gal nano
1. Nothing i get 2.1v
2. heater reads 11.5v
3. Pump reads 11.8
4. Both on i get 13v

So i am under the impression that i do not have a problem but there is something strange going on. When i had first looked on RC this is the thread i found http://www.reefcentral.com/forums/sh....php?t=1953487 I am Mustang in there and if you skip down near the bottom you will find a theory of induction. This is what i was leaning towards when i contacted Marc but then after reading his article i seconded guessed my self as he seemed to make practical sense. Thus leading to my now confused state. Any help or theories as to what is going on would be appreciated as i think Marc has it right but for some reason i can not duplicate his results. Thanks all

FYI i had to go out before i finished this post and decided to stop by my LFS and after testing 2 SW tanks and 3 FW tanks i found similar results as to what i am findings at home.

Here is a pic of my digital testers on my 108gal with everything on.
Click image for larger version

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Comments

  1. melev's Avatar
    From looking at your method of testing, it appears you are putting power in the tank. You need to put one probe in the water, and the other probe in the GROUND.

  2. Mustang's Avatar
    Sorry Marc i think the pic is just not clear as i just used the power bar for ease of use. I am putting the black probes in the ground as you show in your pic just using the power bar rather then an outlet. Any other ideas?
  3. Mustang's Avatar
    Oh and the red probe's where in the sump.
  4. melev's Avatar
    Looks like I misspoke. Looking at your image again, those are indeed the ground holes.

    Perhaps it would be wise to have an electrician look at the power in your house to make sure the wiring to the breakers and to your outlets are installed correctly. If you have any crossed wires, this can happen. Seven years ago, I was building a power center for my reef, and I had a friend help me wire in the outlets. Inadvertently, he reversed the wires in two out of the 15 outlets, but I didn't know this until later. I had to take the whole thing apart and verify every single one of them to make sure there were no other mistakes. I have a feeling that you are dealing with black & white wires reversed somewhere. Odds are there is a nifty tool at Home Depot that you can insert into outlets to make sure the circuits are clean.
  5. melev's Avatar
    It might be called an Electrical Inspector Tester - it looks for neutral polarity, basically. I hope that helps.
  6. Mustang's Avatar
  7. melev's Avatar
    Yes, that is what you could try before hiring an electrician.
  8. dread240's Avatar
    Have you checked to see if there is any current (amperage) flowing to ground? Potential voltage is the minor problem, current is your biggest issue that can cause serious harm.

    Pretty much anything with a magnetic drive is going to put voltage into your tank. It's a simple fact of how power is made. Water is a conductor, not an insulator, so as any magnetic field moves through it a small amount of electricity is generated. Water is not stable at holding energy though, and it does dissipate, but it wouldn't be instant by any means.

    Voltage is not the killer though, never has, never will be. I'll even take a video of hitting myself with 1000v if ya want from my insulation tester It's only at like 2 milliamps so nowhere near enough current to harm you (Hell I get shocked with it almost everytime I'm using it).

    Now a current leak from a device into the tank is a different story. Basically this would be a portion of your houses electrical circuit open to the tank. There is no ground path for it to go inside the tank, so sitting there it does nothing until it is provided a path to ground (which is generally you). Furthermore, since there is no path for the current, there would be no prior signs to an issue or anything to give you a 'oh shit' that would tip you off. That's why ground probes are important. Electricity is very crude, and doesn't LIKE to work. It always takes the path of least resistance... otherwise every crow in the world would have already cooked itself when it lands on a line.
  9. melev's Avatar
    Here's a couple of testers I saw at Walmart tonight.

  10. jml1149's Avatar
    If you switch your multimeter to AC, and measure between the hot (small side) and the ground, you should read 115VAC. Otherwise your ground isn't properly tied in. I would do this at the power strip you're using, and then again directly at the wall which it's tied to.

    Interesting you mention about having a small cut and feeling a tingle. Even a wet human hand, intact, has a significantly high resistance such that we are generally protected. However, once you pierce through the skin, our internal resistance is magnitudes lower, and will conduct with much greater current. That's why dread240 is able to jack himself with the 1000v insulation tester, dry, and be ok. But if he were to puncture his skin with the leads, outcome would not be so good.
  11. DJ in WV's Avatar
    check in your circuit box to see where your ground and commons are hooked in at some older boxes ran both to the same bar check also to see how your box is grounded should have to 2 places it goes to ground/dirt not plumbing. Doubt this is where your problem is but worth a look to make sure things are right. Salt water is funny with electric you defiantly need to have a good ground probe in your system. Also remember you can get a reading from a potato
  12. Mustang's Avatar
    Thanks all for your input. I have been a bit busy the last few days but I have done a few more test as recommend and some where done prior to my post but neglected to share them.

    1. I have tested my tanks for amps and I get 0.0. This is good

    2. The ground for my house is done by way of a ground wire run from my panel to my main water entrance to the house.

    3. Tested the ground and there no electricity there.

    4. Picked up one of the testers that Marc and I were talking about and all my plugs are good except for a couple up stairs that are to be fixed ASAP. But should have no bearing on my issue as they are on different circuits.

    5. Jml I am not sure why you sate I should get 115vac as I thought all home wiring was 120vac. Although this is one of the tests that I had done with my father in-law and I get 121vac.

    6. I also tested a plastic bucket with saltwater in it and get 0.6vac not 0.0vac

    7. Now what I am finding strange and if someone can offer an explanation I think we will be on the right track. Why are all of my tanks (2 SW and 2 FW) showing anywhere from 13-30vac and 5 different tanks at my LFS showing similar readings?

    Hmm I am looking back at dread’s post and thinking maybe it is just the magnetic field that is causing me all the confusion but why then is Marc (and others I assume) able to read 0 when I am not.

    Is anyone else out there in the same boat as me?

    FYI I was bare foot on cement with hands in the tank again tonight and no zap. Oh and I am not trying to start a War here as to who is right I just want to make sure I am safe.

    Thanks all for your continued help.
  13. DJ in WV's Avatar
    In coming voltage from the pole could be anywhere from 105 to 125 depending on your transformer on the pole and how many people are on it. 121v is a good reading most us devices are set to run between 110 and 120 at 6ohz. I would get a copper ground rod and drive it in the ground outside and run another ground wire to it you should have two according to the nec and grounding to plumbing isnt aloud anymore. Im going to go test my tanks and see what I get I will let ya know
  14. Mustang's Avatar
    Thanks DJ i will keep the extra ground rod in mind for the spring as i may have some issues with the ground being frozen and the 4 feet of snow on it.
  15. DJ in WV's Avatar
    I got some milli volt ac and dc though i saw 18v ac once but couldnt get it read that again. Static from water movement, humidity between the water and the ballast could give you some readings. The chemical reaction between the prob and the sw may give you the reading in the bucket or maybe holding charge like a capacitor. The mag drive of pumps may be adding to this as well. I just rewired my place few years ago so i know i dont have any service problems
  16. DJ in WV's Avatar
    btw should have added most readings were neg charge