cap'n pete
Member
How many of us use grounding probes?
Grounding Probe
- Thread starter cap'n pete
- Start date
melbournefl
Member
Interesting question Cap, just read an on-line article about that very thing (damn, wish I'd saved the link, sorry) and the author presented an interesting theory. His thinking was that in *some* (note the word some) cases a grounding probe may actually increase the risks associated with water/electricity. Much like a bird can sit on high-power lines since they are not grounded, there's no danger, add a ground from birt and *poof* fried bird. I'm sorry I don't know what the link is because it convinced me not to use one, just make sure all equipment is properly grounded and GFCI's are protecting all outlets. I'm also going with an closed circulation system to elimate the powerheads from the tank. My only "direct" electrical contact will be the heaters. I know there's the possibility of stray voltage from the external pumps, lights etc. but I think the risks are minimal. JUST MY THOUGHTS.
Later, Paul
Later, Paul
mikealb
New Member
I use a grounding probe and am also an EE (electrical engineer). The ground probe will ensure any stray voltage emited by heaters, pumps, etc is returned to ground, the main purpose for the ground probe. It has nothing to do with protecting anyone from shock. To protect yourself from electric shock, which could be fatal, you must have use a GFI type outlet. The GFI senses the smallest amount of voltage and shuts down, much more quickly than a fuse or ciruict breaker. IMO, its a must! If for some reason you can not install one in the wall, you can make one from about $10 worth of parts or buy it assembled from your LFS or cataloge.
cap'n pete
Member
I was curious because they are now available for under $30 at my LFS. I have never really thought there was a great need but am torn. Since I have added a sump, no electric appliances are in the tank. I wonder if your grounding theory would apply in the sump. I would theorize that if there was loose current in the sump, a grounding probe could disipate it before it reached the main tank. I don't know... I'm sure I will find plenty of other things, ie coral, to add to the tank before I put in a grounding probe.
broomer5
Active Member
If there is voltage in the tank - there will be voltage in the sump when the thing is running.
As long as the siphon is not broken, and a water path connects the sump to the tank, through return line or drains - the path exists.
I too use grounding probes in all my tanks. I've read the pro's and con's many times - I choose to ground all electical devices in my home ..... including my saltwater tanks.
I do not want my tank(s) to become something like a large capacitor, with the saltwater being the dielectric, and me being the potential path of discharge to ground when I reach into the tank.
It's debatable issue for sure - much like other things in this hobby.
I agree that a GFI is a must.
As long as the siphon is not broken, and a water path connects the sump to the tank, through return line or drains - the path exists.
I too use grounding probes in all my tanks. I've read the pro's and con's many times - I choose to ground all electical devices in my home ..... including my saltwater tanks.
I do not want my tank(s) to become something like a large capacitor, with the saltwater being the dielectric, and me being the potential path of discharge to ground when I reach into the tank.
It's debatable issue for sure - much like other things in this hobby.
I agree that a GFI is a must.
bang guy
Moderator
Originally posted by mikealb
I use a grounding probe and am also an EE (electrical engineer).
Excellent!! Can I ask some questions? (well, I guess I will anyway
)It is my understanding that GFCI can only detect a ground fault and NOT a short circuit. Is this true?
If so, then without a ground probe you could get severly shocked even WITH a GFCI if you are not grounded when you reach in to adjust your heater. If a heater is broken or you break it while doing an adjustment the GFCI may not trip without a grounding probe. I have NEVER seen an aquarium heater with a three pronged plug. They are NOT grounded without the probe.
Mike, Can you comment on these items? They are the premise I have been working under and if they are not correct I may need to adjust my thinking.
I currently have all my aquarium stuff on it's own GFCI protected circuit and a probe in each;Display, sump & refugium. I have a probe in each because if I shut off the pump and close the ball valve there's no path from the sump to the display. If I'm tinkering I would shut dwn the pump and this is probably the most likely time I would accidently break a heater.
Thank you,
Guy
mikealb
New Member
Inside of a GFI is a sensor that detects changes in current to the appliance by comparing the current flowing to the appliance and the current flowing from the appliance. A drop off in the current equivalent to about 5 milliamperes turns off all power by tripping a relay within the GFI within a few hundredths of a second. You are correct GFCIs do not measure shorts to ground. So to your point, the highest protection is acheived using both a ground probe and GFCI.
