Hello,
I wish to build a project to measure the electricity usage of a few select items in my home: Furnace (80A @ 220vac), Hot water tank (30a @ 220vac), and Refrigerator (15A at 110vac). I live in Canada, and our residential electricity is 110/220vac at 60Hz. After much research, I've learned that the device to do the measuring at the circuit is the toroidal current transformer (CT) - much like a clamp-on ammeter. This little doughnut shaped component goes around the HOT conductor of a circuit. In the case of a 220vac circuit (such as the furnace), I will need two - one for each HOT conductor. Unfortunately, there is little information on the net about how to select and use a toroidal CT in this application - sigh.....
Here are my unknowns:
- what is the correct toroidal CT to buy?
- will I need different ones for circuits of different maximum loads (15A vs. 80A)?
- a typical toroidal CT has two leads. Across these leads do I measure voltage, or current (or both) to know the current load of the circuit being measured?
This is PHASE one of my project! PHASE two will be interfacing output of the toroidal CTs into a computer for logging purposes. This will involve using some sort of DAC with analog inputs, which might create a new thread.
I don't expect one person to have all the answers, so even partial experienced advice is appreciated.
Cheers,
mike
I wish to build a project to measure the electricity usage of a few select items in my home: Furnace (80A @ 220vac), Hot water tank (30a @ 220vac), and Refrigerator (15A at 110vac). I live in Canada, and our residential electricity is 110/220vac at 60Hz. After much research, I've learned that the device to do the measuring at the circuit is the toroidal current transformer (CT) - much like a clamp-on ammeter. This little doughnut shaped component goes around the HOT conductor of a circuit. In the case of a 220vac circuit (such as the furnace), I will need two - one for each HOT conductor. Unfortunately, there is little information on the net about how to select and use a toroidal CT in this application - sigh.....
Here are my unknowns:
- what is the correct toroidal CT to buy?
- will I need different ones for circuits of different maximum loads (15A vs. 80A)?
- a typical toroidal CT has two leads. Across these leads do I measure voltage, or current (or both) to know the current load of the circuit being measured?
This is PHASE one of my project! PHASE two will be interfacing output of the toroidal CTs into a computer for logging purposes. This will involve using some sort of DAC with analog inputs, which might create a new thread.
I don't expect one person to have all the answers, so even partial experienced advice is appreciated.
Cheers,
mike