DROK A/C PANEL METER AMP READING IS NOT ACCURATE

[ROBERT LO June 6, 2021 at 11:54 pm Post count: 0]

#72864 Reply |

I have a DROK A/C power meter SKU 200199 installed CORRECTLY in my RV. When plugged into shore power my DROK power meter will illuminate and display the watts, amps, kWh & volts. The display colors are good and the brightness is excellent.

The problem is that the power meter displays incorrect amps. When multiplying the power meter displayed watts x volts with a calculator, I get a completely different reading than the DROK meters AMP reading. The amp reading on the power meter is off by more than 2 AMPS.

Is this meter defective or does it have a way to reset and or calibrate?

[DrokKeymaster June 7, 2021 at 10:01 am Post count: 2971]

#72923 Reply |

Hello ROBERT LO,

Did you check the current reading with other meter?  Could you please tell us how large the actual current it is?

And please kindly notice this meter only show active power.

The computational formula for Active power : P=U*I*cosφ (cosφ is power factor)

If the power factor of load is  equal to 1, the Active power can be equal to U*I .

But when power factor is within  0-1, you can’t calulate current  directly by  formula U*I.

Best regards,

DROK

[ROBERT LO June 8, 2021 at 4:08 pm Post count: 0]

#73049 Reply |

While testing I had a small load of 0.67 amps and 124.4 volts on the DROK meter. My Fieldpiece meter read 0.69 amps and 124.7 volts.

The watts on the DROK meter read 43.9 watts.

124.4 volts ÷ 0.69 amps = 83.348 watts

 

My DROK meter is not accurate. Can you please advise?

 

[DrokKeymaster June 9, 2021 at 9:48 am Post count: 2971]

#73137 Reply |

Hello ROBERT LO,

As what we mention before, if  the power factor of load is not equal to 1, you can’t calculate power directly by the  formula P=U*I

There are three kinds of power: Active power(P), Apparent pow er(S) ,Reactive pow er(Q)

Our meter only show Active power.

The formula for Active power is P=U*I*cosφ (cosφ is power factor)

Please check the power factor for your load firstly. In general, the power factor for inductive load is less than 1.

Best regards.

[ROBERT LO June 9, 2021 at 2:43 pm Post count: 0]

#73164 Reply |

How do I check the power factor? and are you saying that that my meter is operating properly?

[DrokKeymaster June 10, 2021 at 8:10 am Post count: 2971]

#73252 Reply |

Hello,

Current and voltage are correct, so  active power reading should be no problem.

You can measure power factor with  power factor meter directly. If it is hard to find that meter,  you need to caluate it by yourself. There are many measurements online, you can refer to some of them.

Best regards.

 

 

[ROBERT LO June 11, 2021 at 12:25 pm Post count: 0]

#73371 Reply |

From what I have explained so far, is my meter operating within manufacturer specifications or my meter defective?

[DrokKeymaster June 17, 2021 at 3:13 am Post count: 2971]

#73999 Reply |

Hello ROBERT LO，

As current and voltage reading are correct, we think  the  active power reading is also  no problem.

If you want to verify that, please try to measure power factor with  power factor meter directly.

Best regards,

DROK

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