Grounding Probe

If you have any device leaking elektricity to the water, and you are
affraid of negative effects on your tank inhabitants, the grounding
probe will make things even worse. It will INCREASE the current
flowing from the failed device to the ground through the water column.
Without the probe, the resistance of glass, wood is high enought
to make the current flow almost zero. The probe will lower this
resistance to zero and current will be limited only with the weak
resistance of broken insulation of the device.

If you narrowed the problem to the light fixture I would look to this
really closer. Does it have metal reflector? Is it correctly grounded?
Lights usualy radiate some electricity to water, but if the fixture
is designed correctly it is negligible.

Do one test: disconnect the probe from ground and put a multimeter
in series with it on a AC current settings. If you measure less then 1mA
I would not worry about. If it is more than that I would fix your lights.
Let me give you an example - the original fluorescent fixture from
CustomSeaLights causes readings on a level about 0.2mA. DIY
fixture I made with my friend gives reading 0.8mA when one lamp is
on and 1.6mA when both lamps are on. This is a reason for us to
redesign reflector and replace glass mirror with grounded polished
aluminium.

In your case I would fix the light fixture and I would get rid of the probe
for sure.

In a matter of your GFCI plug - what is it rated for? 5-6mA?
Or maybe bigger? 1mA current is detectable by human skin. 5mA is
already very painful. GFCI plug will not react to very small currents.

wrote in message ...
Just wondering here...I put a ground probe in one of my tanks and
hooked it up to a GFCI outlet. I was feeling some shocks when I
touched the water. I narrowed the problem down to the lighting.
Anyway, the GFCI never tripped. I thought aside from supposedly
ridding the tank of stray voltage, that it would also trip the GFCI
when the water is touched. I guess not? What's the deal?

wrote:
Just wondering here...I put a ground probe in one of my tanks and
hooked it up to a GFCI outlet. I was feeling some shocks when I
touched the water. I narrowed the problem down to the lighting.
Anyway, the GFCI never tripped. I thought aside from supposedly
ridding the tank of stray voltage, that it would also trip the GFCI
when the water is touched. I guess not? What's the deal?

The GFCI will only protect you against leaking devices that are plugged
into the GFCI. It does not really matter if ground probe is plugged
into the GFCI or not, because the GFCI compares the current in the hot
and neutral wires to detect a fault rather than monitoring the ground
wire. The ground probe merely provides a means for a bad device to leak
to ground and trip the GFCI before you stick your hand in. I would
suggest that you make sure that ALL devices are plugged into the GFCI,
otherwise you are not fully covered. If it still does not trip I would
check to make sure the GFCI is wired correctly.

Well, I thought the outlet was a GFCI since it was in my kitchen not too far
from an actual GFCI outlet. I just tested that one and it did not shut off
the outlet at the tank. Guess I'll be changing that outlet today...although
I think I have a portable GFCI I can attach for now. It's only a temporary
setup for an injured fish. It's a 25 gallon tank with an Eclipse hood and
it's that light that was causing the little shocks. Probably because some
water got inside it. It's a big puffer in there and he splashes allot. So,
anyway I'll just keep the light unplugged for now. I'm sure it's fine and
just needs to dry out.

You're answer though does lead me to another question with my big tank. I
have that on a GFCI outlet (for sure) with 2 power strips plugged into that.
The ground probe is plugged into one of the power strips. Will the probe
still trip the GFCI before I stick my hand in or must it be plugged directly
into the outlet, not the power strip.

Thanks!


"Brian C. Attwood" wrote in message
...
wrote:
Just wondering here...I put a ground probe in one of my tanks and
hooked it up to a GFCI outlet. I was feeling some shocks when I
touched the water. I narrowed the problem down to the lighting.
Anyway, the GFCI never tripped. I thought aside from supposedly
ridding the tank of stray voltage, that it would also trip the GFCI
when the water is touched. I guess not? What's the deal?

The GFCI will only protect you against leaking devices that are plugged
into the GFCI. It does not really matter if ground probe is plugged
into the GFCI or not, because the GFCI compares the current in the hot
and neutral wires to detect a fault rather than monitoring the ground
wire. The ground probe merely provides a means for a bad device to leak
to ground and trip the GFCI before you stick your hand in. I would
suggest that you make sure that ALL devices are plugged into the GFCI,
otherwise you are not fully covered. If it still does not trip I would
check to make sure the GFCI is wired correctly.

Pszemol wrote:
"Brian C. Attwood" wrote in message ...

It should not matter where probe is plugged in as long as it provides a
path to ground. The GFCI trips when it detects that the current in the
host wire is not equal to the current in the neutral wire, meaning that
the difference must be going somewhere else, i.e. the ground probe or
your hand. Whether that current goes through the GFCI's ground wire or
another outlet (or your body) makes no difference. If your powerstrip
was not adequately grounded then that would be a problem.


Everything is right of course, but I need to add GFCI will normally
NOT trip when the current difference, in other words: leakage to
ground is less then 5-6 mA. At this value you may still feel a sting when
you touch the water but the current will be too small for GFCI to trip.
It just protects you from being electrocuted :-)

Good point, although intuitively I would think that a voltage sufficient
enough to cause a 5-6mA current through a person (so-so conductor) might
result in quite a bit more current through a metal ground probe (better
conductor) and thus trip the GFCI. Either way, not getting electrocuted
is always preferred.

In article , Pszemol wrote:

In your case I would fix the light fixture and I would get rid of the probe
for sure.

Do not get rid of the ground probe. It could save your life. All
sal****er tanks should have a ground probe.

what rating of a GFCI should I get? 5-6mA or what ,to insure my safety?
"Brian C. Attwood" wrote in message
...
Pszemol wrote:
"Brian C. Attwood" wrote in message
...

It should not matter where probe is plugged in as long as it provides a
path to ground. The GFCI trips when it detects that the current in the
host wire is not equal to the current in the neutral wire, meaning that
the difference must be going somewhere else, i.e. the ground probe or
your hand. Whether that current goes through the GFCI's ground wire or
another outlet (or your body) makes no difference. If your powerstrip
was not adequately grounded then that would be a problem.


Everything is right of course, but I need to add GFCI will normally
NOT trip when the current difference, in other words: leakage to
ground is less then 5-6 mA. At this value you may still feel a sting
when
you touch the water but the current will be too small for GFCI to trip.
It just protects you from being electrocuted :-)

Good point, although intuitively I would think that a voltage sufficient
enough to cause a 5-6mA current through a person (so-so conductor) might
result in quite a bit more current through a metal ground probe (better
conductor) and thus trip the GFCI. Either way, not getting electrocuted
is always preferred.

now that it is mentioned marc check your GFCI.
"Marc Levenson" wrote in message
...
FWIW, I was getting shocked by my 29g a few times last week. I tried
unplugging one thing after
another to figure out what was causing it, but never could. I have a
grounding probe, btw.

Jose was over, and we checked it together, and still it was very elusive.
Finally, I pushed my cords
firmly into the outlets, and the problem was solved.

Marc


Pszemol wrote:

If you have any device leaking elektricity to the water, and you are
affraid of negative effects on your tank inhabitants, the grounding
probe will make things even worse. It will INCREASE the current
flowing from the failed device to the ground through the water column.
Without the probe, the resistance of glass, wood is high enought
to make the current flow almost zero. The probe will lower this
resistance to zero and current will be limited only with the weak
resistance of broken insulation of the device.

If you narrowed the problem to the light fixture I would look to this
really closer. Does it have metal reflector? Is it correctly grounded?
Lights usualy radiate some electricity to water, but if the fixture
is designed correctly it is negligible.

Do one test: disconnect the probe from ground and put a multimeter
in series with it on a AC current settings. If you measure less then 1mA
I would not worry about. If it is more than that I would fix your
lights.
Let me give you an example - the original fluorescent fixture from
CustomSeaLights causes readings on a level about 0.2mA. DIY
fixture I made with my friend gives reading 0.8mA when one lamp is
on and 1.6mA when both lamps are on. This is a reason for us to
redesign reflector and replace glass mirror with grounded polished
aluminium.

In your case I would fix the light fixture and I would get rid of the
probe
for sure.

In a matter of your GFCI plug - what is it rated for? 5-6mA?
Or maybe bigger? 1mA current is detectable by human skin. 5mA is
already very painful. GFCI plug will not react to very small currents.

wrote in message
...
Just wondering here...I put a ground probe in one of my tanks and
hooked it up to a GFCI outlet. I was feeling some shocks when I
touched the water. I narrowed the problem down to the lighting.
Anyway, the GFCI never tripped. I thought aside from supposedly
ridding the tank of stray voltage, that it would also trip the GFCI
when the water is touched. I guess not? What's the deal?

--
Personal Page: http://www.sparklingfloorservice.com/oanda/index.html
Business Page: http://www.sparklingfloorservice.com
Marine Hobbyist: http://www.melevsreef.com

My GCFI is the breaker itself. When it trips, the room goes dead.

Marc


J wrote:

now that it is mentioned marc check your GFCI.


--
Personal Page: http://www.sparklingfloorservice.com/oanda/index.html
Business Page: http://www.sparklingfloorservice.com
Marine Hobbyist: http://www.melevsreef.com

They aren't. I have two circuits in my room. Each is a 20amp breaker, but one
is GCFI. My lighting is on the GCFI, as well as my heaters. The return pumps
are on the regular outlets.

I've had the electrician out here two times to get it set up the way I like it.

Marc


J wrote:

Marc all your eggs in one basket is a very not smart idea. Home depot has
three for $20 outlet style I'm sure you could install them or I can if you
feel uncomfortable.
"

--
Personal Page: http://www.sparklingfloorservice.com/oanda/index.html
Business Page: http://www.sparklingfloorservice.com
Marine Hobbyist: http://www.melevsreef.com

pumps need the/a GFCI too. Didn't you have a pump failure recently? just a
thought.
feel free to tell me shut up if I'm pestering you..lol
"Marc Levenson" wrote in message
...
They aren't. I have two circuits in my room. Each is a 20amp breaker,
but one
is GCFI. My lighting is on the GCFI, as well as my heaters. The return
pumps
are on the regular outlets.

I've had the electrician out here two times to get it set up the way I
like it.

Marc


J wrote:

Marc all your eggs in one basket is a very not smart idea. Home depot
has
three for $20 outlet style I'm sure you could install them or I can if
you
feel uncomfortable.
"

--
Personal Page: http://www.sparklingfloorservice.com/oanda/index.html
Business Page: http://www.sparklingfloorservice.com
Marine Hobbyist: http://www.melevsreef.com