EKM Metering

Hi,

Now we are using the EKM-Omnimeter-I-v3 for development and we have some questions about installation.

By the EKM-Omnimeter-I-v3 spec if the utility power system uses the "120/240V 120/208V Single-Phase 3-Wire / 2 Lines & Neutral" the spec suggests adding the L1 & L2 CT sensor.

Is it necessary to add two CT sensors? If we only install the L1 CT sensor. Does it have some risks in using the meter? Or just can't get the L2 current value only?

Because in our knowledge the AC L1 L2 current rms value shouldn't be different so we can calculate the total watts using the L1 to L2 voltage and the L1 current to calculate?

Thanks

To our knowledge here are the possible ways that you could install an Omnimeter on a system and get accurate measurements. See the 5 possible electrical systems here: https://help.ekmmetering.com/support/so ... 6000200176

If you have a single phase 3-wire system with 2 hots and a neutral, then yes, you absolutely need 2 current transformers in order for the meter to be accurate. For starters, the amperage in L1 and L2 is not going to be balanced in this type of system. Also, if you only meter one of the legs then you will not be accurate, if you pass both primary wires through the CT you will also not be accurate.

If you have a single phase 3-wire system with 2 hots and a neutral, then here is the wiring instructions you must use in order to be accurate: https://help.ekmmetering.com/support/so ... v-metering

I hope this answers your question.

Yes,

The answers are helpful for us.

Many Thanks!