stray voltage levels in saltwater aquarium

[Gti_Leo]

all this talk abotu stray voltage got me curious so one night i went to test my tank and i got 21.6Vac , so the following day i went to test at a set time, you know what i got .5Vac. turned off the powerbar that supplies power to all my pumps and heater, it dropped .1Vac.

then i remembered about the expriments we all did in science classes when we were kids about the lemon battery and lighting up a light with a lemon.

my hypotheses is that something related to the water chemistry is causing what apears to be leaked or stray voltages in the water and ones a probe is added you are able to cause a current to push through it when there is some sort of resistive load connected. coul,d the addition of a new pump cause a change in chemistry in the water? you bet it could, more surface aggitation can cause an increase or decrease in pH or an increase of some sort of chemical resedue from manufacturing that could cause a varience in the water that may make it slightly more acidic.


i do not have the means to fully prove this with experiments but like i stated one night i tested all and got 21Vac to ground the next day near nothing, which leads me to believe that this voltage isn't coming from any electric devices but possibly someplace else. when you think of all the chemicals and elements added to our salt mixes and the chemical make up of the anode and cathod of a battery you may get the idea that the possibilities of creating a sort of battery out of saltwater may be a possibility

if someone has the means to take this experiment further i would liek to know the outcome

 

[Gregcoyote]

This is a valid explanation to me:


Originally Posted by Jadinop
Stray voltage is not caused from a failing device.

Stray voltage is an induced voltage caused by a spinning magnet (impeller for example) that is submerged in saltwater. To put it simply, a submerged pump with a spinning impeller acts as a small generator. Stray (induced) voltage has low to no current behind it and is easily handled by a ground probe. Many pumps with two prong plugs will cause stray voltage due to the lack of a grounding shield like the 3 prong pumps have.

Leaking or shorting voltage is caused by a failing item like a heater or pump. This voltage has A/C current that is being supplied by the wall socket. This type of voltage is dangerous and cannot be fixed by a ground probe. In this case, a ground probe completes the circuit and causes a bigger problem.

 

[jeffaquarius]

This is a valid explanation to me:


Originally Posted by Jadinop
Stray voltage is not caused from a failing device.

Stray voltage is an induced voltage caused by a spinning magnet (impeller for example) that is submerged in saltwater. To put it simply, a submerged pump with a spinning impeller acts as a small generator. Stray (induced) voltage has low to no current behind it and is easily handled by a ground probe. Many pumps with two prong plugs will cause stray voltage due to the lack of a grounding shield like the 3 prong pumps have.

Leaking or shorting voltage is caused by a failing item like a heater or pump. This voltage has A/C current that is being supplied by the wall socket. This type of voltage is dangerous and cannot be fixed by a ground probe. In this case, a ground probe completes the circuit and causes a bigger problem.

Here is another easy experiment to prove the theory of that author totally false.
Get a small container filled with salt water and bring it next to your tank close to one of your power heads. Get the voltage reading on that container and notice there is nothing to it. Then submerge just a portion of the electrical cord of that power head into the small container. Notice that you now get that stray voltage on that small container. I measured from about 0.5 volts with nothing in it and went up to 10 volts as soon as I submerge the cord.

 

[Gti_Leo]

This is a valid explanation to me:


Originally Posted by Jadinop
Stray voltage is not caused from a failing device.

Stray voltage is an induced voltage caused by a spinning magnet (impeller for example) that is submerged in saltwater. To put it simply, a submerged pump with a spinning impeller acts as a small generator. Stray (induced) voltage has low to no current behind it and is easily handled by a ground probe. Many pumps with two prong plugs will cause stray voltage due to the lack of a grounding shield like the 3 prong pumps have.

Leaking or shorting voltage is caused by a failing item like a heater or pump. This voltage has A/C current that is being supplied by the wall socket. This type of voltage is dangerous and cannot be fixed by a ground probe. In this case, a ground probe completes the circuit and causes a bigger problem.

yes but a generator requires something such as a coil to breakt the magnetic lines of flux generated by the spinning magnet, the water is around it and does not really break this cutting action caused by the rotor like a stator does which is wrapped in coils, which i was trying to say in the other thread. the water may be conductive but it is all around the rotor and does not in theory break the magnetic field that will take this alternating current from end to end the way a generator does.

water also does not conduct a magnetic field. water is still an insolator weather it has the potencial to allow current to flow or not

which is why i do not believe in this stray voltage business that it comes from the pumps, and from my tests on my tank it prove that at one point i could have voltage and at another point i'll have next to nothing. with all pumps running the same at these points.

i can see the moving ions in the saltwater creating more of a charge then the rotors on the pumps. these moving ions beign created by the flow generated by the pumps but i can't see the rotor actually generating these. i need scientific proof to tell me other wise which no one has been able to provide, things that don't make sense to me have only been said

http://www.dieselserviceandsupply.com/How_Generators_Work.aspx

 

[jeffaquarius]

all this talk abotu stray voltage got me curious so one night i went to test my tank and i got 21.6Vac , so the following day i went to test at a set time, you know what i got .5Vac. turned off the powerbar that supplies power to all my pumps and heater, it dropped .1Vac.

then i remembered about the expriments we all did in science classes when we were kids about the lemon battery and lighting up a light with a lemon.

my hypotheses is that something related to the water chemistry is causing what apears to be leaked or stray voltages in the water and ones a probe is added you are able to cause a current to push through it when there is some sort of resistive load connected. coul,d the addition of a new pump cause a change in chemistry in the water? you bet it could, more surface aggitation can cause an increase or decrease in pH or an increase of some sort of chemical resedue from manufacturing that could cause a varience in the water that may make it slightly more acidic.


i do not have the means to fully prove this with experiments but like i stated one night i tested all and got 21Vac to ground the next day near nothing, which leads me to believe that this voltage isn't coming from any electric devices but possibly someplace else. when you think of all the chemicals and elements added to our salt mixes and the chemical make up of the anode and cathod of a battery you may get the idea that the possibilities of creating a sort of battery out of saltwater may be a possibility

if someone has the means to take this experiment further i would liek to know the outcome

Your test lead was not having a good contact to ground when you did the 2nd test.

 

[Gti_Leo]

Your test lead was not having a good contact to ground when you did the 2nd time.

sure was i made sure of it by removign it from the water. and just a reminder it was the bare copper i was grounded to

 

[Gregcoyote]

Good data here;


http://angel-strike.com/aquarium/GFI&TechnicalDetails.html

 

[jeffaquarius]

Good data here;


Technical Details of Stray Voltage in Aquaria

First of all, the author is talking about static voltage. Static voltage is in a form of a Direct Current and has no frequency. The example of static is when you rub an object like the carpet, that object will store a static voltage. Once you discharge it, it drops to 0 volts and stays on that state. The author has a misconception of the stray voltage in salt water tank because it is an Alternating Curren (AC). Your DC meter will not pick it up. In other words it is not a STATIC voltage. I can go on and on but I would rather not. The previous experiment I am suggesting is a "black and white" proof.

 

[Gti_Leo]

just did another test now lights out 25.8Vac, turned off all pumps and powerheads 25.8Vac.

so unless dor some reason power voltage is still getting to my accessories dispite the power bar being off i doubt any sort of power is leaking from anywhere, and i'm leaning to my hypothesis more so being water chemistry

 

[jeffaquarius]

just did another test now lights out 25.8Vac, turned off all pumps and powerheads 25.8Vac.

so unless dor some reason power voltage is still getting to my accessories dispite the power bar being off i doubt any sort of power is leaking from anywhere, and i'm leaning to my hypothesis more so being water chemistry

Here is the explanation to your readings.
You are in Canada and I believe you have a 240 vac power source to your home. The transformer outside your home is in Delta to Delta (480 to 240). That means the 2 wires on your power cord are both hot with respect to ground. Unlike in the US, we have only one side being hot. In your case, when you turn off the switch, the other wire is still hot and that is where your stray voltage is coming from. You have to unplug your power strip from the wall receptacle to isolate your power from the tank.

 

[Gregcoyote]

The electrolysis effect (the lemon battery trick) requires two dissimilar metals to create a electrical flow in a acid (lemon juice). No dissimilar metals, no flow of electrons. Also saltwater is not acidic, but the salt ions cause it to be fairly conductive. Some of this may be just meter halucinations. I do know my two wire power heads and my ph probe create the most stray voltage when measuring tank water to electrical house ground.. I figure if the GFI doesn't trip, I'm okay.

 

[jeffaquarius]

The electrolysis effect (the lemon battery trick) requires two dissimilar metals to create a electrical flow in a acid (lemon juice). No dissimilar metals, no flow of electrons. Also saltwater is not acidic, but the salt ions cause it to be fairly conductive. Some of this may be just meter halucinations. I do know my two wire power heads and my ph probe create the most stray voltage when measuring tank water to electrical house ground.. I figure if the GFI doesn't trip, I'm okay.

Those are another good example of STATIC ELECTRICITY and they are DIRECT CURRENT. In our salt water tank, we are dealing with ALTERNATING CURRENT. You cannot store an AC power and be considered as static. In fact the source is considered as DYNAMIC which is coming from the power generator continuously available with constant voltage. In a transformer the current has an inverse proportion to the number of turns of the coil. Meaning the less turns, the higher the current. In a salt water tank, if one believes that the power head transfer the voltage to the water, then the water surrounding the power head is considered to be just 1 turn. This 1 turn has almost no resistance or close to zero. In Ohm’s law, that 28 vac flowing through a load with no resistance would have been like an electric welding producing lots of sparks. Obviously, this is not the case. The water enclosing a power head with motor actually acts as one solid shield preventing any induction to come out. The experiment I previously suggested, where we have a small container which is totally isolated from the power head and we only submerge the electrical cord into the small container and yet we get that stray voltage in the water inside the said container. It is a direct proof that the voltage is passing through the plastic cord insulation and through the water. The Ground Probe connects the water to ground so we have 0 volts but that 28 vac does not disappear. It is transferred to the electrical insulation with a very high resistance (approx 3 mega ohms). The current flowing through the insulation passing to the water and to the ground is very very minimal (Current=120vac/3,000,000 ohms). That equates to 0.04 mA.

 

[Gti_Leo]

Here is the explanation to your readings.
You are in Canada and I believe you have a 240 vac power source to your home. The transformer outside your home is in Delta to Delta (480 to 240). That means the 2 wires on your power cord are both hot with respect to ground. Unlike in the US, we have only one side being hot. In your case, when you turn off the switch, the other wire is still hot and that is where your stray voltage is coming from. You have to unplug your power strip from the wall receptacle to isolate your power from the tank.

you are wrong, we have the same residential voltage you have pal. single phase240v. 120v phase to neutral 240v phase to phase . our commercial lighting 3 phase is 600v, 347v phase to neutral, 600v phase to phase. unlike the USA which uses 480v phase to phase and 277v phase to neutral.

having said that if it was a delta supply type transformer the eddie currents pushed through the cabl insulation would be cancelled out rendering a test useless, the same way a balanced neutral cancels out the amperage, and why you can't run a lone live conductor in a raceway without a neutral or another wire of the single or 3 phase system to cancel out the sheath current and why all cords, BX, romex, pyro, tech all come with a two wire minimum configuration unless they are large single conductor cables used to run 3phase systems, and then they require non ferous cable trays, clips and a fiber plate on one end and none ferous aluminum plate on the other end so that the sheath currents cannot cause a hot spot in the cable from a counter current cause by an induced voltage on a ferous material like steet or iron

i said it in previous threads i'm an electrician. i know the difference in voltages and supply types. i know the practical and hands on side better then you do, so please don't tell me i'm testing wrong or the voltage i'm testing on is something totally different then it is.

 

[Ingy]

Actually, there is a residential aspect to 3 phase 208V 'Y' supply. Each leg to neutral provides 120v single phase as per the norm. A single apartment/condo unit will only have one leg available to the residence. For heating and plumbing loads (i.e. water booster pumps to the higher floors) pumps can run on the 3 phase or a single cross connection 208V (no neutral). BUT, there is no 240V available as per standard 240V 2 phase supplies. No 240V for dryers or stoves.

Canada does supply much of the electrical power to the US in many parts of the country, and we are all on the same greater grid (remember the big Eastern blackout a few years back), but there are some coding differences, but that has to do only with colour coding.

 

[Gregcoyote]

I love it when electricians argue. My approach was to confirm that a ground probe in the tank isn't necessary and in some cases could make the problem of stray voltages worse. ???

 

[Gti_Leo]

I love it when electricians argue. My approach was to confirm that a ground probe in the tank isn't necessary and in some cases could make the problem of stray voltages worse. ???

and i'm agreeing with that lol

greg i get eletrical engineers are more knowledgable then we are, in theory but when it comes down to alot of the hands on things and practical knowledge, things just whip right over their heads. in a case like this where we are dealign with a low amperage low voltage AC current concepts liek di eletric resistance of a cable insulation have a minimal to null bearign on things. now if we were talkign abotu high current and high voltage then things get more complicated, but a .25 amps at 120v, like come on lol

 

[Gti_Leo]

Actually, there is a residential aspect to 3 phase 208V 'Y' supply. Each leg to neutral provides 120v single phase as per the norm. A single apartment/condo unit will only have one leg available to the residence. For heating and plumbing loads (i.e. water booster pumps to the higher floors) pumps can run on the 3 phase or a single cross connection 208V (no neutral). BUT, there is no 240V available as per standard 240V 2 phase supplies. No 240V for dryers or stoves.

Canada does supply much of the electrical power to the US in many parts of the country, and we are all on the same greater grid (remember the big Eastern blackout a few years back), but there are some coding differences, but that has to do only with colour coding.

we use 3 phase in condos also but thats not the residential supply i'm talkign about i'm talkig nabout neighborhood homes, condos/apartments are not really totally different and while they are 3phase supply loads, two phases and a neutral ar brought to each condo/apratment panel, so it is 120/208v single phase. 3 phase only supplys out of unit power liek halls ways and or high load units like roof tops or boiler pumps etc.last condo i did was a 600v wye main supply service which branched off to supply 3 different load centers and transformers, for condo units. the whole buildign was 103 condos and were feed from a 450kva transformer, with 600 delta supply and a 120/208 wye load side which branced off to three different panels that feed each individule suite with 100 amp 120/208 single phase panels

our color coding is still the same for 120/208v red black blue and white, we have the option for our 347/600v to use the same codign or use yellow orange brown and grey for the neutral (which no one ever uses besides for switch legs) the cost of the wire since its not comonly used outside of control wiring is to high for most people to use

but canada supplies most of the world with natural resources, lumber, oil, minerals, metals, freshwater. we just don't have the man power to refine these resources so we sell it export it out and import the materials. if we had the labor force we could shut ourselves off and live off ourselves for centuries

PS: wye type (just had to be a smart a**)

 

[jeffaquarius]

I love it when electricians argue. My approach was to confirm that a ground probe in the tank isn't necessary and in some cases could make the problem of stray voltages worse. ???

We know that salt water has a very high conductivity (almost 0 ohms). While the fish has much higher resistance compared to the salt water. My question is, where do you think the current will flow? Regardless wither you have the Ground Probe or not, it will not harm the fish. I have it since day one cause I'm not fond of the tingling sensation when working in my tank. A GFCI is recommended and I do have it also. Some people will not use it because they are concerned that it might trip when they are not around. Well I will tell you what, it will NEVER trip as long as you remove that Ground Probe when you are away.

 

[Gregcoyote]

My speciality is pretty exotic. I can wire a server cabinet, but thats about it. The stray voltage thing is still being explained on multiple threads across multiple reef web sites. It is an interesting conversation.

 

[Gti_Leo]

We know that salt water has a very high conductivity (almost 0 ohms). While the fish has much higher resistance compared to the salt water. My question is, where do you think the current will flow? Regardless wither you have the Ground Probe or not, it will not harm the fish. I have it since day one cause I'm not fond of the tingling sensation when working in my tank. A GFCI is recommended and I do have it also. Some people will not use it because they are concerned that it might trip when they are not around. Well I will tell you what, it will never trip as long as you remove that Ground Probe when you are away.

the fish have a higher resistive value sure but when the current is flowing through the water its still flowign through them because they are part of the water, the same reason why if we are standign in water and get shocked the potential for death is VERY high. the current will travel everywhere in the water which is why water and electricity don't mix. if there is a short in the tank, kiss your aquarium goodbye, all bacteria all live stock, gone. there was an episode of LA fishguy were jim had a glass heater break and short out (in the sump) and wiped out the whole system. the current will flow through the water in the return and in the drains, if there is a conecting path it'l follow it. just think of a wire, it'll follow the path, more current will take the path of least resistance back to the source but it'll still flow all over the place and will make your like a living hell. GFI which trips at 5milliamps will minimize the death but if no GFI then you're looking at a short circuit current of 10000 in one second flowign through that system, and that sir will fry anything and anyone in contact with the water.


a tingling feelign you say, i find that hard to believe but who am i to say. if you're gettign a shock from the water a grounding probe will cause more issues and you would know it as a shock because it'll be more then a tingle