I got Two of These...But What Are They?

After pulling the cover off of this Zinsco panel, I found these two “dough-nuts” with wires connected to them.
Never seen them before.
Does anyone know what they are?

Peter W. Bennett, Owner
Residential & Commercial Building Inspections
Infrared Thermal Imaging Services
530 Prospect Avenue Little Silver, NJ 07739
Office 732-758-9887 Cell 732-245-9817
NJ Home Inspector Lic#GI371
NJ DEP Radon MET11140
Certified Infrared Thermographer No.7406
Certified Energy Inspector No. 1364
Certified ASHI Member #205748
Certified Member of INACHI
Authorized United Infrared Contractor
NJInfrared.com - On Roof and Aerial Roof Surveys of Moisture
Roof-IR ~ Moisture-IR ~ Energy-IR ~ BlockWall-IR ~ Equine-IR

101_0110 (Small).JPG

Current Transformers for metering

thanks what are they metering?

Thy likely go to the meter to measure power consumed

Services above 200 amp usually require these to read how much power has been used in the Location .


I’ve seen a few similar looking end-user products like that for homeowners to monitor their own usage. I’ve seen them attached to SE lines to monitor whole-house and also attached to each branch to monitor individual circuits. I had a seller show me the whole system once… it came with a software program so that he could constantly monitor usage and adjust accordingly for energy conservation.