voltage leak

[brianf40us]

If i were to test for a voltage leak how would i do that i know i have to use a multi meter. However here is my question if i put the red tip into the water and the black end into the ground hole on my recepticle in that ground hole do you want to touch the side of the hole or go straight in because if i go strait in with the black probe i dont get anything but as soon as i touch a side with the probe i get a reading. Is it possible that i am shorting out the reading due to touching the sides of the hole.

 

[RogerMcAllen]

The grounding pin on your plug generally makes contact with the side of the hole, and not the bottom.

You are doing the right thing by touching the side, probably just missing the contact in the outlet when you poke straight down the middle.

 

[brianf40us]

On my voltage meter I get a reading from my light fixture. Is that normal i get a reading of 2.5. On my multimeter it is a digital one i have two settings one for 500 and 200 if i set it to 200 i get a reading of 2.5. When i had a FW tank i also got a reading from my light fixture is this normal for light fixture's to do.

PS if i lift my light fixture up i dont get a reading.

 

[Ziggy953]

Moved thread to General Hardware and Equipment discussion.

I'm curious. Why are you checking for leaking voltage? Have you been shocked when you put your hand in the tank?

 

[brianf40us]

I check on a regular basis. Why is it that i have a reading on my multi meter i dont think there should be anything going through my water except H2O hahaha. What ya think? If i pick my light bar of the aquarium my meter reads 0 but when it touches it reads 2.5

 

[Jnam]

Do you remember in grade school when you made a potatoe light a little light? Salt water is an elctrolyte. Any contact with copper will cause a small voltage reading. Try taking your probe and putting it into a salt mix before. you put it in the tank... Now take any flourecent or high ouput light and place it near your water. The EME generated by your light causes the electons in the water to vibrate in a certain frequency thats what your multimeter is picking up. ANother test you can do is take a NO flourecent bulb and put it near your fixture while its on. it will be hard to see but the bulb will floresse (spelling?) even though it isnt connected to a voltage source.

 

[brianf40us]

So is this harmless to the fish?


And why is it that when i lift the light off the aquarium just a little bit it drops the voltage to 0. When i say lift it off the tank im talking about lifting it so it barely does not touch the tank. It is still close to the water just not touching the tank.

 

[Jnam]

Harmless unless the fish are grounded to the voltage source(dont put you light in the water LOL) Although glass and plastic are insulators the surface (especialy in a salty tank because of the salt creep) can conduct the electrons to the water. Voltage alone will not harm the fish... current is the killer... at any given time your fish can be subject to up to 20+ volts in ambient voltage due to the salty conditions... I wouldnt be worried. If you want to test something that will give you a better way of telling if something is shorting to your tank or if a fire hazard exists. Test the current over a load. take a small resistor solder a lead of flexible wire to it. strip about 2 inches of insulator off the end of the wire. heres a pic itll better explain what i am saying...


You are testing for mA you should see close to 0. put your multimeter on its second most sensitive setting.

PS the squigly line that everything is connected to is the resistor

 

[Jnam]

If you get a reading above say 0.01mA that would indicate a short to your water... Be very carefull I take no responsibility if you hurt your self or any of your belongings!!! LOL.

 

[brianf40us]

So if i set my Multimeter to AC 200 what does that mean. Or should i set it to AC 500. AC current is measure in voltage correct? how do i measure current in my water using a multimeter?

If i have a leak into the water would i definitly feel the current when i stick my hand into the water or not?

 

[Jnam]

current is measured in Amperes
Voltage is the pressure at which the electricity moves
Current would be the amount of volume that is moving...


AC 500 setting is to measure the voltage at a limit of 500 volts AC
1 Amp is enough to kill you so if you are seeing a reading at the 200 A reading and the AC setting above 1 then unplug everything. And check to make sure you didnt make little salty snacks of all your fish...


If you have a "leak" yes you would feel it. AC is alternating current. So depending on what you are testing to find the leak you may not use the AC setting instead you may use the DC setting.

Can you type on here the brand name and model # of your multimeter. Also can you tell me what type and brand and model # of your lights? Most pumps use a sealed system so no way that could cause a voltage leak. And if a heater goes and leaks your breaker will go off. Same thing with and submersible pumps they would also trip the breaker.


If your lamps are running DC at the bulb poles then you need to use the DC setting if they are AC.

Please explain what you are testing when you get a reading on your light. the exact setting of your multimeter and exactly where you have placed your probes. This is all very key to understanding what and why you are getting a reading.

The info i gave two posts ago was assuming you were testing for DC voltage. if you have your multimeter set on AC 200 I am hoping that is for the Voltage test of AC with a limit of 200 Volts AC. Not a Amperes setting.

Are you touching your light with your bare skin when you are testing for the AC 500? Because that means you are grounding the circuit through you.

 

[Jnam]

Pictures!!!

 

[jsoong]

Just a different perspective: My heater broke in my FW tank a while back, and I could feel a tingle when touching the light (light is grounded). <I measured 110 V between the tank water & the canopy/ground!> Since mine is FW, it is more of an insulator so less current will flow through me, so I just felt a tingle. In a SW setup I would expect a h*** of a shock!

If you are measuring a voltage differential between the light canopy & ground, I would surmise that the canopy itself is not grounded. Perhaps there is some salt on one of the endcaps that is completing a circuit to the canopy when it touches some salt water at the tank rim? At 20V AC, you might not feel much if it is low current.

My suggestion is that instead of measuring current leaks as a safety check, just assume that there will be high risk of shorts when mixing electricity & SW & act accordingly. Replace the recepticle with a GFI unit. It will cut out the electricity if there is any current (a fraction of a milliamp) between the hot/neutral & ground, protecting you & your fishies. <For the GFI to be most effective, all your electricals should be grounded, some also ground the tank itself.> Ever since my heater incident, all my tanks are plugged into GFI units.

 

[Kurt_Nelson]

My suggestion is that instead of measuring current leaks as a safety check, just assume that there will be high risk of shorts when mixing electricity & SW & act accordingly. Replace the recepticle with a GFI unit.

(That'd be a big "two thumbs up")

And if you're worried about minor "stray" voltage, then use a grounding rod in your tank.

 

[Jnam]

GFI outlet should give you more peace of mind knowing that it will trip like jsoong said with just a fraction of a milliamp change. my final suggestion would be to (depending on your climate) put your heater on a separate GFI circuit that way if the rest goes out while your at work you still can keep the heat on.