Is there a way to have an Apex detect stray voltage in a tank and possibly shutdown the defective piece of equipment?
Is there a way to have an Apex detect stray voltage in a tank and possibly shutdown the defective piece of equipment?
Nothing native that I know of. If you are skilled/knowledgable in electronics, it would theoretically be possible to make a voltage detection circuit that would then closed a relay, allowing Apex to detect it. The problem is, you wouldn’t necessarily know which piece of equipment is causing the stray voltage, so I really wouldn’t advise this anyway. The other issue is that if you don’t have a grounding probe, it’s very common to have some stray voltage. It may either be ‘real’ from an equipment issue or an induced voltage.
What is your specific concern behind wanting to do this? In general, If you have your tank protected with GFI outlets, they will shut down if there is more than 5 mA of leakage current and a grounding probe will eliminate stray voltage.
Note: there is a lot of debate around grounding probes in tanks. I won’t take an official position here as this is not the forum for such a debate. Here is a lenghty thread on grounding probes the goes through most/all off the aspects.
I was reading stories about failed heaters and pumps that caused electrification of the tank water. All of my tank is plugged into GFI outlets so it should be covered. Thanks for the info and link to the grounding probe discussion.
One thing to be aware of is if you have a GFI and a faulty piece of equipment that is exposed to the water, the GFI will not trip unless there is a path to ground. The typical concern is that you become that path which is what GFIs are designed to protect agains. If you have a ground probe installed, that becomes the path and the GFI will trip as soon as the leakage fault occurs. This is one of the reasons people give for not using GFIs and/or ground probes - they don't want equipment to shut down when they're not there.
A couple of potential solutions are to use the Apex Heartbeat function or to have the Apex Head unit plugged into a different outlet so it does not loose power when your other equipment does and will be able to notify you.
There is a neat way to circumvent that. If you wire a resistor in series with the ground probe, you can limit GFCI trips to a certain voltage. Resistance = voltage limit / 20mA. By doing this, you prevent misoperations for small amounts of stray voltage but still protect yourself for large values. 20V limit would give you a 1000 ohm desired resistance in the ground probe. The wattage must be greater than 20mA ^2 * resistance or the resistor can burn up.Originally Posted by Sleepydoc
Sent from my SM-G965U using Tapatalk
That's a great trick. Many/most GFIs are set to trip at 5 mA, though, so I would alter your equation to be R = V/5 mA
Many are. I would still calculate minimum wattage based on 20mA though. If you want to play it real safe, do wattage based on 120V^2/R
Sent from my SM-G965U using Tapatalk
So the inline resister in the ground probe is a nice trick/tool. I still recommend ground probes and multiple GFCI's.
Just setup the GFCI's so that if one trips the other supplies the minimum requirements for the tank so nothing dies.
I'm sure there's a lot of different ways of doing that.
My approach was to put a GFCI on each outlet in my EB8. It can run into some money at about $10 each but is the best way to go IMO.
The resistor trick is a supplement not a replacement for GFCIs. It's a trick to make using a GFCI more palatable for those that were getting regular GFCI trips for things like pump starting, which can sometimes cause GFCI trips with a solidly grounded grounding probe. Before I started doing this, my grounding probe was left in a closet because my unit would trip every time the apex rebooted on my old tank.
Sent from my SM-G965U using Tapatalk
Posting Permissions
Reply With Quote
Bookmarks