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I have a basic multi-meter that I am using to measure amp on a load.

I am trying to figure out how much amps my small entertainment system draws. (LCD TV, PC, speakers.) I want to build a small DC inverter system to feed this entertainment system.

My main power is 220V

My ammeter's lowest scale is 200, the highest is 1000. It only has these two settings. The sale is not marked as amps or milli-amps. I am assuming it's amps due to the missing mA notation.

When clamping around the lead that feeds the whole setup (multi plug), I am getting a reading of 00.3 to 00.4 on the screen (scale, 200).

The system if idling and not really doing anything accept being powered on. Tv screen is on, pc is on, and speakers are on.

I am using this meter. DT266 Multi Meter

My meter, however, just displays "A" (with an Aternating current symbol), and not "ACA".

I would normally assume that this is 0.4 amps . However, that seems low.

Alternatively, I tested this same meter and using the same scale (200) on my car battery charger charging a battery, and there it reads 02.5 . The max amps of the battery charger as written on the label, is 6 amps. So hence 02.5 is then 2.5 amps and not 25 amps.

Which brings me back to my initial question.

Is 0.4 amps a "normal" load for the entertainment system as specified?

Using an online calculator, that converts to about 88 watts.

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  • \$\begingroup\$ Are you clamped around just ONE of the power leads? \$\endgroup\$ – analogsystemsrf Mar 22 at 16:42
  • \$\begingroup\$ You have a multimeter that has a 200A capacity? How much was it? \$\endgroup\$ – Solar Mike Mar 22 at 17:04
  • \$\begingroup\$ @analogsystemsrf , yes, only 1. \$\endgroup\$ – Louis van Tonder Mar 22 at 17:24
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I am trying to figure out how much amps are drawn from my small entertainment system ...

I think you mean drawn by my small entertainment system.

My Ammeter's lowest scale is 200.

Presumably you mean 200 A. But maybe you mean 200 mA?

When clamping around the lead that feeds the whole setup (multi plug), I am getting a reading of 00.3 to 00.4 on the screen (scale, 200).

I would normally assume that this is 0.4 AMPS . However, that seems low?

That seems OK for an entertainment system.

... that converts to about 88 watts.

You haven't told us if the system was quiet or running at max volume.

The meter (which you also forgot to specify) probably has an accuracy specification of +/- 5% of full scale (so 5% of 200 whatever units you're using) on AC +/- 2 or 3 digits so your reading will have very poor accuracy.

If the meter is clamp on then make ten turns of your live or neutral wire through the clamp and take the readings again. Divide the reading by ten to get the current.

enter image description here

Figure 1. The meter in question has only got AC A ranges for 200 A and 1000 A AC. Rather unusually the meter has 180° symmetry on the range selector switch.

This is really the wrong meter for the job but there is plenty of room to wind as many turns as you can into the clamp to improve the reading accuracy.

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  • \$\begingroup\$ Lowest amp scale on a multimeter being "200" - it's more likely to be 200mA, not 200A. But it would be best if the OP would clean up the Question to get this right. \$\endgroup\$ – mike65535 Mar 22 at 16:59
  • \$\begingroup\$ "specification of +/- 5% on AC +/- 2 or 3 digits" - which converts to an error of +/- 10A +/- 0.3A, which would make the whole reading completely useless. Note that '%' always refer to full scale, not to the actual reading. \$\endgroup\$ – asdfex Mar 22 at 17:07
  • \$\begingroup\$ @asdfex: Thanks. I was thinking full-scale but forgot to write it. Fixed. \$\endgroup\$ – Transistor Mar 22 at 17:12
  • \$\begingroup\$ Thanks for the answer. I have updated my question based on your comments. \$\endgroup\$ – Louis van Tonder Mar 22 at 17:26
  • \$\begingroup\$ See the update. \$\endgroup\$ – Transistor Mar 22 at 17:51

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