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On the energy meter installed by my utility company (a 1-year old digital Landis+Gyr), I noticed the following steady-state readings when my inverter air conditioner (with a variable speed compressor) was running and I am trying to figure out what could be happening Voltage: 230V Current: 2A Power Factor: 1.0 Power: 315W. Clearly the power reading is [happily] much less than expected - ordinarily I would expect power to be V times A times PF but that is not the case. To ensure the energy meter was not defective (it's just a year old) I connected a 200W incandescent lamp and got 0.75A with 175W, which shows that the meter is correct to within a small margin of error. Can I conclude that the lower-than-expected Wattage reading for the AC is because the compressor is probably drawing pulses of current rather than a continuous 2Amps? (I am not conversant with the exact speed control mechanism of inverter ACs.) If so would it then imply that energy meters such as the Landis+Gyr are NOT designed to show true RMS currents?

Thanks - Ram

On the energy meter installed by my utility company (a 1-year old digital Landis+Gyr), I noticed the following steady-state readings when my inverter air conditioner (with a variable speed compressor) was running and I am trying to figure out what could be happening Voltage: 230V Current: 2A Power Factor: 1.0 Power: 315W. Clearly the power reading is [happily] much less than expected - ordinarily I would expect power to be V times A times PF but that is not the case. To ensure the energy meter was not defective (it's just a year old) I connected a 200W incandescent lamp and got 0.75A with 175W, which shows that the meter is correct to within a small margin of error. Can I conclude that the power shown by the energy meter is lower than VxAxPF for the AC is because the compressor is probably drawing pulses of current rather than a continuous 2Amps? (I am not conversant with the exact speed control mechanism of inverter ACs.) If so would it then imply that energy meters such as the Landis+Gyr are NOT designed to show true RMS currents?

Thanks - Ram

On the energy meter installed by my utility company (a Landis+Gyr), I noticed the following steady-state readings when my inverter air conditioner (with a variable speed compressor) was running and I am trying to figure out what could be happening Voltage: 230V Current: 2A Power Factor: 1.0 Power: 315W. Clearly the power reading is [happily] much less than expected. To ensure the meter was not defective I connected a 200W incandescent lamp and got 0.75A with 175W, which shows that the meter is correct to within a small margin of error. Can I conclude that the lower-than-expected Wattage reading for the AC is because the compressor is probably drawing pulses of current rather than a continuous 2Amps? (I am not conversant with the exact speed control mechanism of inverter ACs.) If so would it then imply that energy meters such as the Landis+Gyr are NOT designed to show true RMS currents?

Thanks - Ram

On the energy meter installed by my utility company (a 1-year old digital Landis+Gyr), I noticed the following steady-state readings when my inverter air conditioner (with a variable speed compressor) was running and I am trying to figure out what could be happening Voltage: 230V Current: 2A Power Factor: 1.0 Power: 315W. Clearly the power reading is [happily] much less than expected - ordinarily I would expect power to be V times A times PF but that is not the case. To ensure the energy meter was not defective (it's just a year old) I connected a 200W incandescent lamp and got 0.75A with 175W, which shows that the meter is correct to within a small margin of error. Can I conclude that the lower-than-expected Wattage reading for the AC is because the compressor is probably drawing pulses of current rather than a continuous 2Amps? (I am not conversant with the exact speed control mechanism of inverter ACs.) If so would it then imply that energy meters such as the Landis+Gyr are NOT designed to show true RMS currents?

Thanks - Ram

I have a Landis+Gyr energy meter installed by my utility company. I noticed the following steady-state readings when my inverter air conditioner (with a variable speed compressor) was running and I am trying to figure out what could be happening Voltage: 230V Current: 2A Power Factor: 1.0 Power: 315W. Clearly the power reading is [happily] much less than expected. To ensure the meter was not defective I connected a 200W incandescent lamp and got 0.75A with 175W, which shows that the meter is correct to within a small margin of error. Can I conclude that the lower-than-expected Wattage reading for the AC is because the compressor is probably drawing pulses of current rather than a continuous 2Amps? (I am not conversant with the exact speed control mechanism of inverter ACs.) If so would it then imply that energy meters such as the Landis+Gyr are NOT designed to show true RMS currents?

Thanks - Ram

On the energy meter installed by my utility company (a Landis+Gyr), I noticed the following steady-state readings when my inverter air conditioner (with a variable speed compressor) was running and I am trying to figure out what could be happening Voltage: 230V Current: 2A Power Factor: 1.0 Power: 315W. Clearly the power reading is [happily] much less than expected. To ensure the meter was not defective I connected a 200W incandescent lamp and got 0.75A with 175W, which shows that the meter is correct to within a small margin of error. Can I conclude that the lower-than-expected Wattage reading for the AC is because the compressor is probably drawing pulses of current rather than a continuous 2Amps? (I am not conversant with the exact speed control mechanism of inverter ACs.) If so would it then imply that energy meters such as the Landis+Gyr are NOT designed to show true RMS currents?

Thanks - Ram