Can it be used to measure DC amps? None of my other meters can handle more than 10 amps and I suspect a motor I have draws more than 10 amps. It has stranded 10 gauge wire. Must be a reason for that.

 

Yes there are DC clamp meters.

 

Let me try again, can I use my AC clamp meter to measure DC amps?

 

Probably not going to work because micro in the meter is not programmed to do it.
It will show something, I just don't think it will be right.

 

Some AC clamp meters will work, if they use Hall Effect elements. But a "normal" transformer type will not.
I think they will have a DCA setting if they can measure DC

 

5:40 PM Mountain - tremor.

How would I know if I have a transformer type?

[edit] Opened the back. Four wires come from the clamp. Connect to silk screen labeling L1 & L2. Probably pure AC only.

 

It is probably a transformer type if there is no DC setting.

 

L1 and L2 sound like inductors, L is usually used to indicate inductor. Transformers are sort of inductors.

 

No, its going to only work on AC.

If you didn’t pay $500-2000 for it, it’s not going to be a fancy unit designed for both AC and DC

 

Can you wire in a shunt resistor?

https://www.digikey.com/product-detail/en/vishay-dale/WSBS85181L000JK34/541-3325-ND/6709520

As others have said, non contact DC current measurements are relatively rare and expensive.

 

I can wire in a shunt; I have one intended for a small cheap panel meter that displays both voltage and current. It's rated for 100 amps. I'm sure it won't be very accurate but accuracy is not so important at this point in the venture.

 

No, it will not work for DC. It is an inductive device.

There are Hall Effect based clamp on ammeters. Sears (Craftsman) has an ~$80 unit that will do DC. I have one, it is cheap and only measures to 0.1 amps but it's all that I needed at the time. If I need better accuracy or precision I'll wire a shunt resistor or use an ammeter inline.

 

Thanks LV.

 

No, its going to only work on AC.

If you didn’t pay $500-2000 for it, it’s not going to be a fancy unit designed for both AC and DC

You can have a very well built one for about US$40. (Uni-T UT210E)

If you don't mind used, you can have a Fluke Y8100 for even less. For this one, you will need an external multimeter.

 

If it is the old moving coil/needle type ammeter, they only work with AC.
The dual AC/DC ammeter attachment for my Fluke meter was around $150.00.
Max.

 

There is a way to read DC current with an AC clamp type of meter but it is tedious and it requires an adjustable DC power supply with an ammeter. From the DC supply a wire is wrapped around the same leg of the clamp on meter so that the current flows in the opposite direction from the current being measured. If there are 10 turns on the wire then the max current can be up to 10 times the supply current. The supply current is adjusted so that there is no needle movement as the clamp is opened and closed, indicating that the two magnetic fields are cancelling each other. Then multiply the supply current reading by the turns ratio and you have the other wire's current, within the ability of detecting that the fields are cancelling.
I told you that the process was tedious, didn't I?

You can also use your current shunt, which really should be quite accurate, almost as accurate as your millivolt DC meter. Just make sure that all of the connections are tight and not a shock hazard.

 

You can also use your current shunt, which really should be quite accurate, almost as accurate as your millivolt DC meter. Just make sure that all of the connections are tight and not a shock hazard.

Was planning on using the shunt. We're only working with 12 volts. But thanks for the caution.

 

https://www.amazon.com/1mA-DC-Clamp...r&qid=1559253983&s=gateway&sr=8-1-spons&psc=1

$43 bucks

• [1mA Sensitivity]: 1mA sensitivity when measures AC/DC current by clamp.
• [Dual Line Display]: Dual line display can show both AC voltage/current and frequency or Celsius and Fahrenheit on the screen.
• [Low Impedance Mode]: Low Impedance (LoZ) mode for identifying and eliminating ghost or stray voltages.
• [Activate V-Alert at Any Function]: Activate V-Alert (non-contact voltage detection) function under any function design makes non-contact voltage testing more convenient.
• [Back Clip Design]: Back clip design make it more portable, hang on your belt or pocket.

 

Was planning on using the shunt. We're only working with 12 volts. But thanks for the caution.

OK, not much of a shock hazard, but with big wires at 12 volts you can generate a whole lot of heat really fast if there is a short circuit.

So what sort of motor are you testing? Just curious as to what sort of things anybody has come across.

 

So what sort of motor are you testing?

In another thread I'm building a high amperage PWM to control a blower motor from a BMW. When I asked the guy at the scrap yard he said the motor draws 6 amps. I'm just not comfortable with his assertion. A 6 amp motor doesn't need 10 gauge stranded wire. Before I commit components to the task I want to verify the actual amperage. This is a picture of all the information listed on the motor. I've searched and can find replacement blowers but no information on its draw. I'm currently on a BMW site asking for information regarding this but so far I've gotten no responses. If ANYONE can find info on this - I sure would appreciate the help.