electricity meter

[PG1995]

Hi

Please have a look here.

What does it mean? It might mean that the maximum current which could flow thru meter is 30A. Do I have it right? And what about "5"? Thank you.

Regards
PG

 

[dr pepper]

With it being chinese I couldnt be certain, however that would normally mean 5a inductive load and 30a resistive load.
'Standards' vary so it could mean something totally diffrent.

 

[JimB]

Have a look here:
**broken link removed**

The first number appears to be the "Test Amp Rating", effectively the current at which it is calibrated.
The second number is the maximum load current, which is generally 666.66% of the Test Amp Rating.

I think that I have just learned something.

JimB

 

[dr pepper]

Me too.

 

[KeepItSimpleStupid]

OK,me too.

 

[gary350]

Best thing to do is call the power company and ask them what it means.

 

[moty22]

It could also mean 5A continues 30A max, a sensible spec.
Don't be so unkind to the Chinese, they gave us the gunpowder so we can blow each other up.

 

[Tony Stewart]

It could also mean fake specs to be meet customer requirements. The original part is only 5(20) indicating a ratio of 400% which declines with higher current units.

Model : DDS844
Material : ABS
Accuracy : Class 10
Rated Voltage : 110, 120, 220, 230, 240V
Rated Current : 1.5(6), 2.5(10), 5(20), 10(40), 15(60), 20(80), 30(100)

It is supposed to mean 5A continuous and no loss in accuracy at (peak currents )

https://www.banggood.com/DDS9666-52...-Two-Wire-Electric-Energy-Meter-p-955160.html

Looks like "no attempt" to "cover-up" the cover-plate photo-edit.

 

[dr pepper]

No unkindness meant, esp as there may be members here of that origin.
I was just saying saying that standards vary in diffrent countries.

 

[Tony Stewart]

Perhaps the pulse width of the peak is a factor. But generally pulse width is at least 1 cycle such as motor surge currents at 8x on start at peak voltage.

But then for $8, and no detailed spec, what do you expect?

 

[moty22]

Perhaps the pulse width of the peak is a factor. But generally pulse width is at least 1 cycle such as motor surge currents at 8x on start at peak voltage.

But then for $8, and no detailed spec, what do you expect?

When you switch on your computer the peak current is about 30A till the 470 uF in the power supply is charged. It must be a requirement by some standard and the Chinese way is to correct the label. They put CE mark on their products without even knowing what it means.

 

[PG1995]

Thank you, everyone.

We have a single phase meter and it has written "10(40)A" on it. It can easily run two 2 ton air conditioners which approximately consume 4 kW which gives us the current of 18A (current=4000/220).

The labeling "X(Y)" is quite common on electricity meters. To confirm this you can have a look on some of the pictures from Google.

So far, in my humble opinion, JimB's explanation sounds more feasible.

The first number appears to be the "Test Amp Rating", effectively the current at which it is calibrated.
The second number is the maximum load current, which is generally 666.66% of the Test Amp Rating.

Thank you.

 

[RODALCO]

The 5 Amps is the base load or the test current of the meter.
The 30 Amps is the maximum current for which the meter will measure accurately within its class specifications.
The thermal maximum load may be even another 20 % higher, depending upon the cable size and ability to dissipate heat from the meter terminals, the meter will be under reading as the current coil will saturate at excessive currents.
That linemens reference book is great data specific to American made meters.

 

[rumpfy]

I googled a few DDS844 references, and they all showed the numbers 5(20).
My GUESS is the 20 (30) is the current rating and maybe the 5 is the calibration value.
In Australia, there has been a huge love affair with electronic metering, and the electromechanical type has largely been superseded by the all electronic (remotely disconnectable, remotely read) types.
Electricity meters are required to be able to measure 60 amps per phase and I am certain the performance across the full load range would have to be guaranteed to better than 2% error under all conditions.