Measuring individual circuits in a standard service panel

Poolguy
Poolguy Registered Users Posts: 10
I'm looking for a way to measure current usage on several individual circuits in my service panel to calculate loads for my PV system. Of course each circuit is wired directly to a GE circuit breaker. I am thinking of making a pigtail of sorts to hook up my Killawatt meter inline so I can use it to measure current etc.
Each circuit is 110 volts and generally low power such as room lights and plugs so I don't think it would be dangerous if I hook it up using safety precautions.

Any thoughts or ideas?
Thanks!

Comments

  • NorthGuy
    NorthGuy Solar Expert Posts: 1,913 ✭✭
    Re: Measuring individual circuits in a standard service panel

    I did that. It doesn't look pretty, but I only needed it temporarely.

    You remove the circuit wire from the breaker and connect it with a bell to the red wire. You put the black wire into the breaker (from where you removed the circuit wire). You connect white to the neutral bus.

    Then you plug KaW into the outlet and then plug the plug into it.

    It can measure halfs of 240V circuits too, but it cannot do big circuits - KaW has limits.
  • BB.
    BB. Super Moderators, Administrators Posts: 33,431 admin
    Re: Measuring individual circuits in a standard service panel

    You do not want to hack in a Kill-a-Watt meter... There are others out there (folks can give you some other links)--But you can start looking at:

    http://www.theenergydetective.com

    They have multi-port models available (you place a current transformer around each circuit to monitor).

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    Re: Measuring individual circuits in a standard service panel

    If you want to use a K-A-W to temporarily measure loads that are hard-wired in circuit it is better to interrupt the circuit at the load rather than in the service panel: it is less likely to make a wiring mistake or cause a short.

    Remove the wiring from the load and connect it to a standard outlet instead. Then connect a short pigtail plug to the load (make certain to use proper wire size). Connect the meter in between and take the measurements.
  • Ralph Day
    Ralph Day Solar Expert Posts: 1,019 ✭✭✭✭
    Re: Measuring individual circuits in a standard service panel

    I got one of these. Not sure about the rounding of consumption numbers. You can put the supplied clamp on meters on single or whole house supply wires (I've only monitored whole house)
    http://www.mtpinc.com/SearchResults.htm?PG=1&CDT=1378556229

    Ralph
  • BB.
    BB. Super Moderators, Administrators Posts: 33,431 admin
    Re: Measuring individual circuits in a standard service panel

    I did not get Ralph's link to work--But they do have an interesting data logger:

    http://www.mtpinc.com/Products.htm?CD=106

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • Ralph Day
    Ralph Day Solar Expert Posts: 1,019 ✭✭✭✭
    Re: Measuring individual circuits in a standard service panel

    Bill, I just tried my link and went right to the site. Might be because of caching on my computer tho.

    Ralph
  • inetdog
    inetdog Solar Expert Posts: 3,123 ✭✭✭✭
    Re: Measuring individual circuits in a standard service panel
    Ralph Day wrote: »
    Bill, I just tried my link and went right to the site. Might be because of caching on my computer tho.

    Ralph

    Your link does not specify the search criteria used, but instead specifies the results of a particular numbered search. As such it is temporary and possibly even tied to a cookie in your browser only.
    You can sometimes get a better result by going to one or more of the links on that page, finding one which shows what you are actually interested in, and then posting that link.
    SMA SB 3000, old BP panels.
  • Poolguy
    Poolguy Registered Users Posts: 10
    Re: Measuring individual circuits in a standard service panel
    NorthGuy wrote: »
    I did that. It doesn't look pretty, but I only needed it temporarely.

    You remove the circuit wire from the breaker and connect it with a bell to the red wire. You put the black wire into the breaker (from where you removed the circuit wire). You connect white to the neutral bus.

    Then you plug KaW into the outlet and then plug the plug into it.

    It can measure halfs of 240V circuits too, but it cannot do big circuits - KaW has limits.

    That is exactly what I need to rig up. I need to measure the current at the box as some of the lights downstream are hard wired into fixtures etc.
    Thanks for the pic and tip!
  • solarix
    solarix Solar Expert Posts: 713 ✭✭
    Re: Measuring individual circuits in a standard service panel

    Hialeah Meter in Florida sells reconditioned utility meters for under $20. Utilities are constantly pulling out these old mechanical types as they transition to electronic ones and they are available cheap. Your local home store should have the meter can to mount it. This is almost cheaper than buying a Kill-a-watt but can handle 100A/240V. Like Jim Lovell in "Apollo 13" says: Let's get it right!