Question for using GFCI and grounding probe

[mcgyvr]

Your house isn't going to burn down if you don't have a GFI breaker on your return pump give me a break.

No but you could be electrocuted.. Thats what GFCIs are required for.
Not fire prevention.

oh yeah.. post 4000

 

[mcgyvr]

That said, I find that pumps and/or cracked heaters are usually the reason for a stray voltage in your aquarium. Sometimes there is not much you can do to get around it. It could be a tiny leak in conductor insulation on one of the pumps you may never find it. a grounding electrode should help with the problem. It can be plugged into any outlet (GFI outlet wont make any difference).

mains voltage exposed to the water is NOT stray voltage..
Stray voltage is the induced/coupled voltage from rotating magnets in pumps or from lighting sources/ballasts (typically never more than 1/3rd line voltage).. "stray voltage" is the voltage reading you get when you just hold a multimeters probes in the air near a light source,etc.... With everyone in their mom now having a cheap but sensitive (high impedance) multimeter the word "stray voltage" is everywhere as people wonder why the meter is showing anything..

and IF you are going to use a ground probe you MUST have it on a GFCI..
Without one current WILL flow with nothing stopping it..
(ever made a saltwater rheostat load.. lets see.. brine solution.. check.. conductive metal at different potentials separated by a distance submerged in the saltwater.. check) You have just made a resistive load..which will be a heater too.. Maybe you haven't as 15 years an EE puts you pretty young still so that may be before your time.

Its ok.. electrical engineers are just like anyone else.. We all make mistakes from time to time and don't know everything..

 

[mcgyvr]

Choosing a safer path is the intelligent thing to do. Spreading ignorance is not. I realize that you may know what you are talking about, but for those that dont understand electronics, they may walk away with something a lot less informed because some internet electrical engineer said, "Dont worry about it". Please don't do that in this thread.

No matter what way you slice it. Having a GFCI on ALL aquarium power sources is better than not having it.

Great response!.. :thumbsup:

 

[stage3-s4]

No.. a GFCI monitors between line and neutral..
Neutral is not the same as ground even though they are tied together at the panel board.
"Ground" should ONLY carry current in the event of a fault.. Thats it..

No motors can have high "leakage current" thats NOT inrush current. But yes you can have common mode voltage imbalances that can make their way to a grounded portion of the motor through the bearings. This is far more common with motors that utilize a VFD

Yes you are correct. I was thinking line to neutral in my head I don't know why I i said neutral to ground. In any event the concept is the same. Yes I'm aware the neutral and equipment ground are not the same and only bonded at the service entrance.

I'm not sure what you mean motors have high leakage current. I was just talking about the imbalance from high inrush due to starting that causes you to have current on the neutral. A VFD would be a way to avoid this since it eliminates the high inrush current. I'm sure most people are not going to put a VFD on there tiny 1/3 hp aquarium pump. a DC pump is nice alternative.

Its not some hidden secret its pretty common knowledge. I had an issue with a GFI tripping on a large motor 1-2HP or so. No mater what I did, change the motor 3 times, changed the starter, changed the GFI receptacle 4 times, changed the wiring, changed to a GFI breaker, it would still trip! Probably should have tried a VFD at that point. Read any literature and most will recommend to not use GFI protection on large motors. Its a fact.

 

[stage3-s4]

Choosing a safer path is the intelligent thing to do. Spreading ignorance is not. I realize that you may know what you are talking about, but for those that dont understand electronics, they may walk away with something a lot less informed because some internet electrical engineer said, "Dont worry about it". Please don't do that in this thread.

No matter what way you slice it. Having a GFCI on ALL aquarium power sources is better than not having it.

I'm only offering advice. I'm not saying don't use a GFI ever on any aquarium. I'm simply saying that you may be banging your head against the wall when your GFI constantly trips and your tanks goes in the shitter because your pumps dont work. (its happend on many situations of fellow reefers). If that is a better option to you than more power to you. I'm not telling anyone to not doing anything unsafe. I'm only making suggestions from experience.


How in anyway is that being ignorant? How can you judge someone on something you are not even knowledgeable in? I'm not coming in here claiming everyone is an idiot because they don't know how a GFI works.

"in my expert opinion I would not feel any way unsafe not using GFI protection on larger external pumps for home aquariums" Some my disagree with this which is fine, but for some reason people on here take this to heart.

 

[stage3-s4]

mains voltage exposed to the water is NOT stray voltage..
Stray voltage is the induced/coupled voltage from rotating magnets in pumps or from lighting sources/ballasts (typically never more than 1/3rd line voltage).. "stray voltage" is the voltage reading you get when you just hold a multimeters probes in the air near a light source,etc.... With everyone in their mom now having a cheap but sensitive (high impedance) multimeter the word "stray voltage" is everywhere as people wonder why the meter is showing anything..

and IF you are going to use a ground probe you MUST have it on a GFCI..
Without one current WILL flow with nothing stopping it..
(ever made a saltwater rheostat load.. lets see.. brine solution.. check.. conductive metal at different potentials separated by a distance submerged in the saltwater.. check) You have just made a resistive load..which will be a heater too.. Maybe you haven't as 15 years an EE puts you pretty young still so that may be before your time.

Its ok.. electrical engineers are just like anyone else.. We all make mistakes from time to time and don't know everything..

Thank you for the semantics lesson. You are right leakage current and stray current are not one in the same. Stupid me I should have clarified that (im sure many of the folks here needed to know).

I didn't make a mistake. I was talking about the ground conductor itself. The entire system is interconnected so connecting it to any equipment ground in any outlet will have the same outcome. But you are so smart right you knew that?

I don't need someone criticizing my career or years of experience in the business. I'm doing just fine. If you think 15 years is just a drop in the bucket than more power to you. I'd rather be young than old.

And yes we all make mistakes even someone perfect like you.

 

[stage3-s4]

No but you could be electrocuted.. Thats what GFCIs are required for.
Not fire prevention.

oh yeah.. post 4000

I'm talking about larger external pumps like iwakis, bluelines, darts, reflows, etc. The only realistic way you would get electrocuted without a GFI on one of these pumps is if you basically soaked the entire pump in salt water (Most are drip rated assemblies). Not just a little drip here and there. It would be pretty hard to get electrocuted from there in my opinion (anything is possible of course if you don't think before you act).

I never recommended against GFCI protection on items actually inside the tank or sump that is in constant contact with salfwater. I actually recommend it.

GFCIs are used for fire prevention in other applications as well.

 

[jeremybunn]

Alive me is better than dead reef tank.

But I want it all!!??

Easy work around? Use a gfci per device.

They are 12 bucks now at home depot, easy to do, worth the cost?

Have kids? It's a no brainer.

Plug each device into one of these, a trip means one device down not all.

Don't forget the ground probe!

 

[stage3-s4]

I'm talking about larger external pumps like iwakis, bluelines, darts, reflows, etc. The only realistic way you would get electrocuted without a GFI on one of these pumps is if you basically soaked the entire pump in salt water (Most are drip rated assemblies). Not just a little drip here and there. It would be pretty hard to get electrocuted from there in my opinion (anything is possible of course if you don't think before you act).

I never recommended against GFCI protection on items actually inside the tank or sump that is in constant contact with saltwater. I actually recommend it.

GFCIs are used for fire prevention in other applications as well.