Troubleshooting Amp Meter

[summerofgeorge]

I don't want to debate whether an amp meter is necessary. I have one already and just want to make it work...

I have a meter like this: http://www.ebay.com/itm/3-1-2-Blue-...131?pt=LH_DefaultDomain_0&hash=item5adb01fc8b

When I power my panel up, the meter comes on and shows 0A. I've tried plugging a few things into the panel but the meter stays at 0. I think I have it wired correctly (one hot leg going through the shunt and the two monitoring wires across the shunt). Power is coming from a wall wort within my panel. I thought there could be a problem with the power source so I powered the meter from a outlet outside of my panel but still nothing.

Is there a good way to test it? I'd almost like to replace my separate volt and amp meters with a combo meter but then I'd have an extra hole in my panel. Any suggestions on something else to put in the hole?

 

[1MadScientist]

Do you have it hooked up to a DC power supply, as in this link?

http://www.theelectricbrewery.com/control-panel-part-2?page=9

 

[-CHRIS-]

I've tried plugging a few things into the panel but the meter stays at 0.

What are you plugging into the panel? You need something with a meaty load like a vacuum, pump or heating element to register anything on the meter.

The ammeter is very useful for troubleshooting PID issues and calibration.

Chris

 

[summerofgeorge]

I'm powering the meter with an old cell phone charger that puts out about 11V DC (meter says 8-12V AC or DC for input).

I had a space heater hooked up because I figured that would draw enough. I also tried a 12 amp vacuum and still nothing.

 

[summerofgeorge]

I also just tried powering it with a 9V battery. Same story. Powers up but nothing moves it from 0.

 

[-CHRIS-]

Try reversing the polarity (flipping the wires) on the meter/shunt connections. The way that type of meter works is it very accurately measures the voltage drop across the shunt. If the meter is receiving "negative" voltage it may not register.

You can also check the function of the shunt with a regular multimeter, you should read a few mv of voltage drop across the shunt.

The meter could also be broken. I think you are wasting your time messing with the power supply, if it lights up it should work. I think your problem is with the shunt, your wiring or the meter itself.

more than 1 amp of draw should easily register.

Chris

 

[augiedoggy]

Try reversing the polarity (flipping the wires) on the meter/shunt connections. The way that type of meter works is it very accurately measures the voltage drop across the shunt. If the meter is receiving "negative" voltage it may not register.

You can also check the function of the shunt with a regular multimeter, you should read a few mv of voltage drop across the shunt.

The meter could also be broken. I think you are wasting your time messing with the power supply, if it lights up it should work. I think your problem is with the shunt, your wiring or the meter itself.

more than 1 amp of draw should easily register.

Chris

I agree. I have a few of these and had one behave the same way when converting my popup to solar power, it was a defective meter in my case..
I also agree that they are very useful to see whats going on or not working.

 

[Takuie]

Definately try flipping the leads if still a no go, meter is bad. I found a schematic on Google showing the leads are wired backwards compared to how the original ad shows.

Also, make sure your shunt is on the hot leg of the load. You can also compare it to the readings from a handheld multimeter with an amp probe. If multimeter shows load present, and your box display doesn't then it is a defective amp meter.

Sad thing about those China ebay companies, it takes forever to return and receive a new one. For the 7 bucks, I'd just take it in the nose and order another one.

 

[augiedoggy]

I seen multiple seller in the states selling the dual volt/amp meters for about $11 if you dont want to wait. I believe it was amazon actually. I bought and used 2 so far with no problems. The one I had an issue with was a dc voltage one.

 

[summerofgeorge]

Well I tried flipping the wires and still nothing. Looks like I'll be getting a new one. I'd like to go with the combination volt/amp meter. Problem is that I already have 2 holes in my panel. Any suggestions for the other hole if I go with the combo? Here's the current layout: