Grounding Probe Noise

[BirdGuy21]

So I have s concerning, strange question. I have a grounding probe plugged into my 45 gallon tank. While sitting down tonight watching the tank after unplugging and plugging back in pumps for feeding, I hear strange noise coming from the tank. I said it sounds like a mix between a crackling like radio static and my girlfriend said more like a running toilet. So I go and unplug everything one by one thinking a pump is burning up or failing- nothing. The only thing left to take out of the water is the grounding probe- and the noise stops. Place it back into the water and the noise starts back up again

So I place it on top of my screen lid, which is made out of plastic mesh and aluminum rails, like from the framing of a window screen. The metal part of the probe was only touching the plastic. I go to move the lid and get a decent shock from the metal sides.

So what is going on? Should I be concerned about something emitting high amounts of electricity into my tank?

 

[BirdGuy21]

Ok so it happened again only very loud this time. Turns out it was the heater....heater failure. The outer casing of the heater tube was turning white in a spot. Thankfully it only increased my temps about 1 degree, so it must have just started.

 

[TheHarold]

That makes sense. I was going to say- I can’t think of a way that a solid metal probe can make a noise like you described, must be something else.

 

[sandswhitson]

Nice catch. What kind of heater? Had it ever been out of the water while still turned on?

 

[BirdGuy21]

Aqueon pro heater, 200w. I can’t say for sure if it was ever run out of water as I bought the tank setup used in November. Since then it definitely has not been turned on when not submerged.

Really glad I caught it in time. I’m guessing the stray voltage from the heater was being picked up by the grounding probe and caused some sort of vibration or created a frequency of some kind, thus the noise.

 

[A sea K]

Wow, thats pretty scary! I was reading a thread the other day on the topic of grounding probes, from what I gather they are best used in conjunction with a gfci of some sort, the idea being the gfci (with a probe)will immediately be able to detect the stray voltage and trip the breaker. It also seems that probes or gfci by themselves only offer minmal protection and in some cases can be more dangerous than nothing at all. Jury is still out for me, my system is powered by a dedicated circuit with a gfci breaker but I have no ground probe.

 

[ihavecrabs]

@Brew12 you might find this interesting

 

[scriptmonkey]

Is the probe connected to a GFCI outlet?

 

[Brew12]

@Brew12 you might find this interesting

Very interesting, thanks for the invite!

I'm a big fan of the GFCI/Ground Probe combination. I have a failing piece of equipment in my system that could be leaching copper or other heavy metals I want to know about it ASAP. I also want it de-energized since current flow will speed up most types of corrosion. I could remove my ground probe now since I use titanium heaters with 3 prong ground plugs. They do the same things a ground probe.

I will say that it must have been one heck of a fault if it were causing a vibration. Makes me wonder if your breaker is bad.

 

[A sea K]

I could remove my ground probe now since I use titanium heaters with 3 prong ground plugs. They do the same things a ground probe.

Would this still be the case if the heaters are run off of (through?) a ranco controller?

 

[scriptmonkey]

Yeah. I thought with the probe that as soon as the stray voltage went to ground it would immediately trip.

What does not make sense is if he pulled the probe out of the water with the failing heater why was it still energized enough to shock him when he touched the lid aluminum?

 

[Brew12]

Would this still be the case if the heaters are run off of (through?) a ranco controller?

Not familiar with the Ranco's but yes, it should be the case on any properly designed controller. The ground prong should not be interrupted by the control circuit, only the hot.

Yeah. I thought with the probe that as soon as the stray voltage went to ground it would immediately trip.

What does not make sense is if he pulled the probe out of the water with the failing heater why was it still energized enough to shock him when he touched the lid aluminum?

Without a GFCI nothing would trip until the total circuit had reached 15 amps or more.

Best guess is this. The OP removed the ground probe which had been shunting the voltage from the heater to ground. This kept the tank water at the same potential as ground. When he removed the ground probe, fault current stopped flowing but the tank water then went to 120V. When he touched the aluminum lid, he became the best path for that electricity to flow to ground and he got shocked. It wasn't the ground probe the caused the shock. The current path was most likely: Heater ->water->salt creep->aluminum lid->person->ground

 

[scriptmonkey]

That's what I was missing. Jump from water to aluminum...stupid salt creep, screwing EVERYTHING up! again.

 

[A sea K]

Not familiar with the Ranco's but yes, it should be the case on any properly designed controller. The ground prong should not be interrupted by the control circuit, only the hot.

So far as I know the Ranco is actually a commercial grade controller so I would assume properly designed. Thanks for the info, very helpful for me!

 

[BirdGuy21]

Electricity is so interesting, especially considering how we use it as aquarists to safely power equipment in water.

Stupidly the probe was not connected to a GFCI outlet at the time. The heater that was causing the problem was quickly removed, thankfully I had a replacement ready to go. What makes it worse is I have been meaning to hook it up to my ReefKeeper Lite controller, but hadn't gotten around to it. Suffice it to say the replacement heater is already hooked up and being controlled by the RKL- which I am hoping would help prevent future failures.

Another potential disaster avoided the following morning- since the fault occurred late at night and I am usually in bed by the time I had it all figured out, I failed to notice that the heater tripped the powerblock it was plugged into, causing the wavemaker and ATO to go offline. I realized the next morning that the water level looked low and discovered my mistake. Thankfully the salinity only increased from 1.026-1.027 and everything seemed okay. So, lessons learned- plug the grounding probe into a GFCI outlet, pay attention to details, and improve my cord management.

 

[Brew12]

Electricity is so interesting, especially considering how we use it as aquarists to safely power equipment in water.

Stupidly the probe was not connected to a GFCI outlet at the time. The heater that was causing the problem was quickly removed, thankfully I had a replacement ready to go. What makes it worse is I have been meaning to hook it up to my ReefKeeper Lite controller, but hadn't gotten around to it. Suffice it to say the replacement heater is already hooked up and being controlled by the RKL- which I am hoping would help prevent future failures.

Another potential disaster avoided the following morning- since the fault occurred late at night and I am usually in bed by the time I had it all figured out, I failed to notice that the heater tripped the powerblock it was plugged into, causing the wavemaker and ATO to go offline. I realized the next morning that the water level looked low and discovered my mistake. Thankfully the salinity only increased from 1.026-1.027 and everything seemed okay. So, lessons learned- plug the grounding probe into a GFCI outlet, pay attention to details, and improve my cord management.

You may want to install a GFCI outlet with an audible alarm to let you know immediately.

 

[BirdGuy21]

You may want to install a GFCI outlet with an audible alarm to let you know immediately.

Definitively on the list for the weekend project.