Go Back   Aquarium Advice - Aquarium Forum Community > Saltwater and Reef > Saltwater Reef Aquaria
Click Here to Login

Join Aquarium Advice Today
Reply
 
Thread Tools Search this Thread Display Modes
Please support our sponsors and let them know you heard about them on AquariumAdvice.com
 
Old 05-10-2013, 06:13 PM   #131
Aquarium Advice Apprentice
 
Join Date: Apr 2011
Posts: 10
Meter was set to AC Volts btw. 28 Volts
__________________

__________________
jamey is offline   Reply With Quote
Old 05-10-2013, 07:13 PM   #132
Aquarium Advice Apprentice
 
Join Date: Apr 2011
Posts: 10
Quote:
Originally Posted by jeffaquarius View Post
Have you checked your electrical outlet (receptacle) if it has a good ground? If you get some voltage reading between the ground (round) and the neutral (larger flat) on outlet you have a grounding problem. The voltage difference between larger hole and round hole in outlet (smaller hole as common when measuring) must be close to zero volt. Check also your grounding probe if it has good conductivity (must be less than 1 ohm). They are sometime covered with algae and what not.
Ok, I did these checks, with a good AC voltmeter, and everything checked out ok. 0 Volts between the ground and Neutral, and 0 Ohms. Also confirmed that the larger hole on the receptacle is the Neutral.
So I am assuming that I have had stray induced voltage in my tank this whole time from the pumps, and I am just noticing it now for one reason or another. I am switching everything back to the same circuit (Thanks Jaffaquarius for the wake up call) Can I just live with the stray voltage for now, and turn the pumps off when servicing? Never had a problem with the livestock in the 20 months it's been running. Everything seems to be healthy and thriving.
__________________

__________________
jamey is offline   Reply With Quote
Old 05-10-2013, 10:10 PM   #133
Aquarium Advice Addict
 
jeffaquarius's Avatar
 
Join Date: Jan 2013
Location: Los Angeles, California
Posts: 1,933
I am satisfied 100% with what this author is saying about the Ground Probe
Aquarium Grounding Probes
For me the primary purpose of having a Ground Probe in my tank is to eliminate the electrical hazard for myself and not for the fish. Now it is up to you to choose and decide which is more important, is it your life or your fish. A GFCI (Ground Fault Circuit Interrupter) is a good idea and I might have to put one too. You don't need to have a Ground Probe if you have GFCI. You need not worry for it to trip when you are not around because it will never happen. As long as your water is not grounded it will not trip. The reason is because GFCI is looking for unbalance current between Neutral and Hot to trip. Unbalance occurs when some current leaks to Ground. Therefore, it will only trip when the water is grounded by your body and if there exist an excessive stray voltage from your pumps and heaters. Or you can put your Ground Probe only when servicing your tank.
__________________
jeffaquarius is offline   Reply With Quote
Old 05-11-2013, 06:57 PM   #134
Aquarium Advice Apprentice
 
Join Date: Apr 2011
Posts: 10
Ok, so I confirmed that the two receptacles I was using were on different hot legs. Measure the voltage between the two and it was around 270 Volts on my meter. Now everything is back on the same leg, and I'm back to 28Volts Stray Voltage.
Thinking about ground probes now.
Would it still be dangerous if I split the loads like before, dropped the stray/induced voltage down to 1.4V, and used ground probes, so if something went wrong the GFCI's would trip, eliminating the danger of exposing the water to 240 Volts. This way I would only be discharging 1.4Volts rather than 28Volts through the ground probes when things are normal. Just a thought.
I absolutely do not want to stress the fish, but I don't want to get electrocuted either.
__________________
jamey is offline   Reply With Quote
Old 05-11-2013, 07:36 PM   #135
Aquarium Advice Addict
 
jeffaquarius's Avatar
 
Join Date: Jan 2013
Location: Los Angeles, California
Posts: 1,933
Remember about the birds setting on a high tension wire and the reason why they are not affected by the 35 kilovolts? It is because there is no current flowing in the air or in their body. Current will only flow if you provide a path between 2 points with different potential (volts). The same thing applies in the stray voltage in your tank. That 28 vac you are measuring in your tank with respect to ground is a stand still voltage and no current flowing. It is a false notion that it affects your fish. As stated on that link you posted, it is the other way around. Once you have that Ground Probe in the water, you have just provided a path for that stray voltage to flow to ground. It is still not advisable to have 2 different circuits in your tank. I don't believe either that a current flowing in the water will affect your fish for the simple reason that salt water has more conductance compared to the flesh of fish therefore the current will just flow thru the water not through the fish. High Tension Electricians use Ground Probe so they can touch the wire which may still have some stray voltage in it. Therefore, I suggest you do the same thing. Just use the Ground Probe when maintaining your tank or have a GFCI so you don't have to worry about forgetting to put your Ground Probe.
__________________
jeffaquarius is offline   Reply With Quote
Old 05-11-2013, 08:08 PM   #136
Aquarium Advice Addict
 
jeffaquarius's Avatar
 
Join Date: Jan 2013
Location: Los Angeles, California
Posts: 1,933
Quote:
Originally Posted by jamey View Post
Would it still be dangerous if I split the loads like before, dropped the stray/induced voltage down to 1.4V, and used ground probes, so if something went wrong the GFCI's would trip, eliminating the danger of exposing the water to 240 Volts.
If you are willing to use 2 GFCI for your set up then yes you can. You don't need a Ground Probe when you have GFCI. Another caution, if you use Ground Probe only with 2 circuits in your tank, the stray voltage may be cancelling out with respect to ground but not inside your tank. You now have 2 different potentials and current may be flowing inside your tank without you knowing it.
__________________
jeffaquarius is offline   Reply With Quote
Old 05-11-2013, 09:48 PM   #137
Aquarium Advice Apprentice
 
Join Date: Apr 2011
Posts: 10
Quote:
Originally Posted by jeffaquarius View Post
Another caution, if you use Ground Probe only with 2 circuits in your tank, the stray voltage may be cancelling out with respect to ground but not inside your tank. You now have 2 different potentials and current may be flowing inside your tank without you knowing it.
Excellent point. Your advise is well taken. Thanks!
__________________
jamey is offline   Reply With Quote
Old 05-12-2013, 06:23 PM   #138
Aquarium Advice Addict
 
jeffaquarius's Avatar
 
Join Date: Jan 2013
Location: Los Angeles, California
Posts: 1,933
Quote:
Originally Posted by Gregcoyote View Post
Found this:

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.



And this:


Aquarium Grounding Probes

It seems that there is little current involved and most of the voltage is induced by the pump impeller actions and from any two wire immersed devices you might have.
But it also seems to me a probe isn't a bad idea, as a GFCI will detect and trip any significant current, the probe will keep the seawater at the same ground potential (voltage) as the house wiring has. But in the end, no one thinks even my 34 volts is a big deal on all the posts I have studied so far.
Sorry Greg but I have to disagree with the idea that the stray voltage is coming from the motor. If it is, how would you explain the stray voltage from the heater when there is no motor on it? It actually comes from the electrical insulation of your equipment submerge in the water. Plastic and rubber are non conductive but they do have dielectric capacitance. Even space has some dielectric capacitance but very minute. AC will pass thru capacitors but DC does not. This explains why the more equipment and length of wires submerged in the water the higher your stray voltage reading becomes. Use DC motors and heaters and I guarantee you will not have any stray voltage in your tank. Not practical though. Just get a GFCI and case close.
__________________
jeffaquarius is offline   Reply With Quote
Old 05-13-2013, 04:39 PM   #139
Aquarium Advice Addict
 
Gregcoyote's Avatar



Tank of the Month Award
 
Join Date: Feb 2011
Location: Columbia, Missouri
Posts: 8,320
I throw away a cheap pump at least one a year. The two wire kind with no ground. Had one almost fry me a few weeks ago. The pumps can leak or cause inductive voltages as mentioned above, in the tank. Some ph probes can also leak a small amount of current. It's almost impossible to get to zero if you have several pumps actually in the tank because of the effects of induction. The only exception are the expensive wave makers that keep the motor section on the outside of the tank.
__________________
Gregcoyote is offline   Reply With Quote
Old 05-23-2013, 10:13 PM   #140
Aquarium Advice Addict
 
jeffaquarius's Avatar
 
Join Date: Jan 2013
Location: Los Angeles, California
Posts: 1,933
This same issue was discussed in another thread and I was demonstrating where it is coming from.
tank temp has.been steady rising..
However, there is another way of proving this with more convincing result. Remove the Grounding Prove first if you have one. Using a good digital voltmeter, measure the existing stray voltage in your tank and record it for reference. Then submerge the remaining electrical cord of one of your power heads that is running except the plug of course. Measure again the new stray voltage reading and you will notice it is higher than the previous reading. My 26 vac went up to 28 vac which increased by 2 volts. I'm in the US and I have 120 vac power for my equipment. This explains exactly where the stray voltage is coming from. The more equipment and electrical wire submerged, the higher your stray voltage becomes. No need to throw away those power heads if you have GFCI.
You can avoid getting a shock from stray voltage by laying a rubber matting on the floor where you stand when working in the tank.
__________________

__________________
jeffaquarius is offline   Reply With Quote
Reply

Tags
aquarium, level, salt, saltwater, saltwater aquarium

Please support our sponsors and let them know you heard about them on AquariumAdvice.com

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off








» Photo Contest Winners








Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -4. The time now is 09:42 PM.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.