Ammeter/multi meter wiring

[mogmog2]

I'm having trouble with this cheapo PZEM -031 multi meter I bought to get an idea of the output from my wind generator (at the moment I have only a Nasa BM2 which gives a net reading and includes solar)
AIUI, the load should be pos from the turbine charge controller and neg to the house battery (bus bar) and the two DC are just 12v (from the house bus bars) to power the unit?
However, if I wire it thus, the DC negative sparks when the wire touches the terminal and gets warm if left in contact.
Any ideas? Many thanks

 

[Alex_Blackwood]

I'm having trouble with this cheapo PZEM -031 multi meter I bought to get an idea of the output from my wind generator (at the moment I have only a Nasa BM2 which gives a net reading and includes solar)
AIUI, the load should be pos from the turbine charge controller and neg to the house battery (bus bar) and the two DC are just 12v (from the house bus bars) to power the unit?
However, if I wire it thus, the DC negative sparks when the wire touches the terminal and gets warm if left in contact.
Any ideas? Many thanks
View attachment 196546

This the instructions diagram, can't see what you have wrong. Oh yes I can!
Bit confusing but looks as though the DC in should come from the wind geny. and then the output should be connected across the load. (Battery)

 

[mogmog2]

This the instructions diagram, can't see what you have wrong. Oh yes I can!
Bit confusing but looks as though the DC in should come from the wind geny. and then the output should be connected across the load. (Battery)

Thanks for this. Unfortunately I'm not sure how what I've done differs from the diagrams you found (beyond using buses instead of battery terminals).

 

[andsarkit]

I would wire it up exactly as shown and not connect the two negatives to a bus bar. It could either sense the current in the positive or negative lines so you need to make sure both go through the meter and not connected elsewhere..You could be right to connect the battery on the power supply terminals to keep it constantly reading. It would then normally read discharge from the battery and hopefully also read a current flowing in from the wind charger as the opposite polarity.
For a test, connect the battery and then put a small load on the load terminals and see what it reads.

 

[mogmog2]

I would wire it up exactly as shown and not connect the two negatives to a bus bar. It could either sense the current in the positive or negative lines so you need to make sure both go through the meter and not connected elsewhere..You could be right to connect the battery on the power supply terminals to keep it constantly reading. It would then normally read discharge from the battery and hopefully also read a current flowing in from the wind charger as the opposite polarity.
For a test, connect the battery and then put a small load on the load terminals and see what it reads.

Thanks for this. I'll have a look in the morning. We've got a few hours for the tide.

 

[VicS]

Thanks for this. I'll have a look in the morning. We've got a few hours for the tide.

I suspect your meter may be unsuitable for your purpose . It will take its own power from the DC input terminals which in your case will be the input from the wind gen controller. Normally this will be a battery or other stable and continuous power supply. Perhaps it will work while the wind gen is charging but I suppose that is when you want it to work !

Also. Assuming you want your battery monitor to monitor the house battery the battery negative and monitor shunt wiring is incorrect as shown. It will monitor the two batteries combined

If the power for the meter coming from the wind gen is OK then the diagram below may help

 

[William_H]

I think the problem is with cheap volt meter/ amp meters that the current shunt in the meter is connected to negative supply for the meter. This can be confirmed with an ohmeter between the negative supply wire and the negative current sensing wire. That means that the current sensing can only be done in the negative wire of the load.
Either move current sensing to negative supply or provide an isolated supply voltage. This can be done with a small 9v battery or a specific converter isolating input volts to output volts. Something like this or even smaller. Pardon Our Interruption...
ol'will

 

[Alex_Blackwood]

View attachment 196555

I suspect your meter may be unsuitable for your purpose . It will take its own power from the DC input terminals which in your case will be the input from the wind gen controller. Normally this will be a battery or other stable and continuous power supply. Perhaps it will work while the wind gen is charging but I suppose that is when you want it to work !

Also. Assuming you want your battery monitor to monitor the house battery the battery negative and monitor shunt wiring is incorrect as shown. It will monitor the two batteries combined

If the power for the meter coming from the wind gen is OK then the diagram below may help

View attachment 196580

+1 for that, Basically what I tried to say in #2. I don't think? he is worried about monitoring the two batteries as what he wants is the output from his W/G ?
I also think that you are correct in saying that the meter may be unsuitable for that application. The load Terminals are designed to have a resistive or inductive load i.e. lamp, motor etc. not a voltage source such as a battery.
Is the input to the charge controller ac or DC? from the OP's diagram it looks like ac. He would need to get on the DC input to the controller from the Geny. and connect that to the DC terminals of the meter and connect the load terminals of the meter back to the DC input terminals of the controller.
It might then work, or not as the case may be. What make Geny. and controller?
I hope the above makes sense, haven't time to do a diag.

 

[andsarkit]

It claims to store the data when the power is off. In that case you could connect the wind generator to the power terminals and the battery to the load. As soon as the voltage gets up to 6.5v it should start recording again. The only way to find out is to do a test and see what happens. Certainly worth trying and report back on what you find. You might find that a slowly rising and varying voltage causes it to get a mess as the wind generator starts up. Perhaps a large capacitor on the input might help with this.
If all this fails you could just put in an analogue ammeter and keep it simple.

 

[Alex_Blackwood]

It claims to store the data when the power is off. In that case you could connect the wind generator to the power terminals and the battery to the load. As soon as the voltage gets up to 6.5v it should start recording again. The only way to find out is to do a test and see what happens. Certainly worth trying and report back on what you find. You might find that a slowly rising and varying voltage causes it to get a mess as the wind generator starts up. Perhaps a large capacitor on the input might help with this.
If all this fails you could just put in an analogue ammeter and keep it simple.

See #8 Ah hae ma doots that connecting a voltage source to the load terminals of the meter will work.

 

[[70521]]

I'm having trouble with this cheapo PZEM -031 multi meter

This might be your problem!

One came with my last boat, a complete work of fiction.

 

[andsarkit]

At £4.62 delivered it might be worth a punt and you won't feel bad about binning it if it doesn't work. I got a similar one to check the power comsumption of my fridge which is impossible without something to total all the switching cycles. It came out at 20Ah per day which I was quite pleased with, if correct. I also want to put it on my tillerpilot which is another intermittent load.
Coming from an electronics background I still can't be;ieve how they do it for the money. Most of our work systems were into the hundreds of thousands.

 

[S04]

Isn't that exactly the device that the OP already has? He mentions PZEM-031 in post #1.