How to measure dedicated circuits

RichardU
RichardU Registered Users Posts: 19
To measure a load with a Killawatt, it needs to be plugged in. But I have a lot of dedicated loads (e.g. ceiling lights) I'd like to measure (over time if possible). Does anyone have a good way to do that?

Comments

  • NorthGuy
    NorthGuy Solar Expert Posts: 1,913 ✭✭
    Re: How to measure dedicated circuits

    When I needed this, I buit a simple device where KaW may be plugged in. The white wire is connected to neutral bas. I remove the circuit wire from the breaker, connect it to the black wire. Then I insert the red wire into the breaker. Or, was it black wire to breaker and red wire to circuit? Don't remember now.

    KaW is then plugged into the outlet, and the plug is plugged into the KaW. Very klugy, but worked for me.

    Disclaimer: Don't try that at home.
  • tons001
    tons001 Solar Expert Posts: 71 ✭✭
    Re: How to measure dedicated circuits

    http://efergy.com/us/products/engagee2hub
  • RichardU
    RichardU Registered Users Posts: 19
    Re: How to measure dedicated circuits

    Thanks Northguy, very ingenious.

    And thanks Solar Hobbyist. I've seen things like before including google power. Unfortunately it would not give circuit level data.

    I'm actually investigating building something based on an Arduino.
  • solar_dave
    solar_dave Solar Expert Posts: 2,397 ✭✭✭✭
    Re: How to measure dedicated circuits

    You can measure individual circuits with a TED, I measure 4 lines with mine. I do wish it was more however.
  • tons001
    tons001 Solar Expert Posts: 71 ✭✭
    Re: How to measure dedicated circuits

    I don't have it but it was something I remembered reading about awhile back and thought it might be a fit. I wonder if you move the sensor from hot leg of a circuit in the panel to another once a week to get circuit level data for a week. I also did not research how many sensors could be added but the cost would far outweigh NorthGuys solution.

    Marc
  • RichardU
    RichardU Registered Users Posts: 19
    Re: How to measure dedicated circuits

    Thanks solar_dave. The TED is a bit pricy, but looks like it would do the job. BTW, I clicked on your link for My TED 5000 System and it was a dead end for me.
  • solar_dave
    solar_dave Solar Expert Posts: 2,397 ✭✭✭✭
    Re: How to measure dedicated circuits
    RichardU wrote: »
    Thanks solar_dave. The TED is a bit pricy, but looks like it would do the job. BTW, I clicked on your link for My TED 5000 System and it was a dead end for me.

    Yeah it is an issue with my DNS provider, since I have a dhcp address from my provider. I wil chase it later this week.
  • Coach Dad
    Coach Dad Solar Expert Posts: 154 ✭✭
    Re: How to measure dedicated circuits
    NorthGuy wrote: »
    When I needed this, I buit a simple device where KaW may be plugged in. The white wire is connected to neutral bas. I remove the circuit wire from the breaker, connect it to the black wire. Then I insert the red wire into the breaker. Or, was it black wire to breaker and red wire to circuit? Don't remember now.

    KaW is then plugged into the outlet, and the plug is plugged into the KaW. Very klugy, but worked for me.

    Disclaimer: Don't try that at home.

    Nice job North Guy...
    This is clever.:D
  • RichardU
    RichardU Registered Users Posts: 19
    Re: How to measure dedicated circuits
    NorthGuy wrote: »
    When I needed this, I buit a simple device where KaW may be plugged in. The white wire is connected to neutral bas. I remove the circuit wire from the breaker, connect it to the black wire. Then I insert the red wire into the breaker. Or, was it black wire to breaker and red wire to circuit? Don't remember now.

    KaW is then plugged into the outlet, and the plug is plugged into the KaW. Very klugy, but worked for me.

    NorthGuy: just to be clear: the red wire goes to the hot side of the socket, the black wire goes to the same side of the plug. Did you connect the white wire to the other side of the socket or the plug or both?
  • NorthGuy
    NorthGuy Solar Expert Posts: 1,913 ✭✭
    Re: How to measure dedicated circuits
    RichardU wrote: »
    NorthGuy: just to be clear: the red wire goes to the hot side of the socket, the black wire goes to the same side of the plug. Did you connect the white wire to the other side of the socket or the plug or both?

    I connected the white (neutral) wire to both. You need to make sure that the construction of the plug is such that you cannot insert it backwards.
  • RichardU
    RichardU Registered Users Posts: 19
    Re: How to measure dedicated circuits
    NorthGuy wrote: »
    I connected the white (neutral) wire to both. You need to make sure that the construction of the plug is such that you cannot insert it backwards.

    I figured that much, so I'm using one with a ground prong. Thanks.
  • RichardU
    RichardU Registered Users Posts: 19
    Re: How to measure dedicated circuits

    Hmmm. I'm trying the NorthGuy circuit, but not getting good results.

    I set my 4460 at $1 per kwh just to simplify the math -- I really want to know annual kwh per circuit. So first I hook the 4460 directly to a 75 watt bulb, and pretty quickly it tells me I will spend about $650 per year which is what 75 watts times 24 hours times 365 days equals. Good.

    Next I hook the 4460 to the NorthGuy device which is on a circuit with 8 @ 65 watt ceiling bulbs. That's 520 watts, so it should tell me my annual consumption will be $4,555. Instead it says $8.76. So it's only detecting a trace of the total usage.

    Something tells me it's because the white wire to the circuit is still connected the buss. If I disconnected that wire, and ran it straight to the plug it would mechanically duplicate the effect of plugging in a table lamp. It would also complicate the usage of the device since my white wires into the buss are harder to identify than the black wires into the breakers.

    Any thoughts?
  • BB.
    BB. Super Moderators, Administrators Posts: 33,431 admin
    Re: How to measure dedicated circuits

    Be careful with "white wires"--They are the center tap of a 120/240 VAC system. They only carry the "difference" in current of the two 120 VAC hot leads (black and red).

    And if you disconnect a white return wire--You can get 240 volts across your 120 VAC loads (and a shock/electrocution hazard too). While wires should never be disconnected unless all of the breakers for the circuits are off (or whole house mains pulled).

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • NorthGuy
    NorthGuy Solar Expert Posts: 1,913 ✭✭
    Re: How to measure dedicated circuits
    RichardU wrote: »
    Something tells me it's because the white wire to the circuit is still connected the buss. If I disconnected that wire, and ran it straight to the plug it would mechanically duplicate the effect of plugging in a table lamp. It would also complicate the usage of the device since my white wires into the buss are harder to identify than the black wires into the breakers.

    Any thoughts?

    I had a very all Kill-a-Watt meter. It died when I measured things outside. I cannot verify this now, but I suspect it wasn't even of Kill-a-Watt brand. When I ordered a new Kill-a-Watt from eBay, I noticed that the buttons were in a different positions. It could be one of two things:

    1. My old one had a sensor on the hot wire, and the new one may have the sensor on the neutral wire

    or

    2. You wired the hot wires on the left side of the outlet/plug and neutral wires on the right side.

    If this is #1, you probably can fix it by doing #2 and running wires backwards, but I strongly recommend against this. The better solution is to connect the neutral from the plug to the neutral of the circuit instead of the outlet. Of course, you need to disconnect the circuit's neutral wire from the bus then. This complicates things.

    If this is #2, it's easy to fix.
  • RichardU
    RichardU Registered Users Posts: 19
    Re: How to measure dedicated circuits

    I already tried reversing the wires, and the result was identical. So I suspect they are sensing the neutral wire which is unfortunate. I have 160 recessed lights in my house and I was really hoping to track usage. I'll investigate some of the alternatives.
  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    Re: How to measure dedicated circuits

    Interrupt both wires.
  • jcheil
    jcheil Solar Expert Posts: 722 ✭✭✭
    Re: How to measure dedicated circuits
    RichardU wrote: »
    I have 160 recessed lights in my house...

    Holy crap! 160 lights? In a house?
    Off-Grid in Central Florida since 2005, Full-Time since June 2014 | 12 X Sovello 205w panels, 9 X ToPoint 220w panels, 36x ToPoint 225w panels (12,525 watts total) | Custom built single-axis ground mounts | Complete FP2 Outback System: 3 x FM80, 2 x VFX3648, X240 Transformer, FLEXnet-DC, Mate-3, Hub-10, FW500 AC/DC | 24 x Trojan L16RE-B Batteries 1110ah @ 48v | Honda EU7000is Generator and a pile of "other" Generators | Home-Made PVC solar hot water collector | Custom data logging software http://www.somewhatcrookedcamp.com/monitormate.html
  • RichardU
    RichardU Registered Users Posts: 19
    Re: How to measure dedicated circuits
    jcheil wrote: »
    Holy crap! 160 lights? In a house?

    According to my electrician: "You can dim down, but you can't dim up."

    It's a big house, and we went a little overboard. I'm trying to prioritize replacing the 65w bulbs with LEDs.
  • jcheil
    jcheil Solar Expert Posts: 722 ✭✭✭
    Re: How to measure dedicated circuits
    RichardU wrote: »
    According to my electrician: "You can dim down, but you can't dim up."

    It's a big house, and we went a little overboard. I'm trying to prioritize replacing the 65w bulbs with LEDs.

    I can't imagine how much additional (wasted) air conditioning it takes to keep up with the heat produced from THAT many lights! Might pay for all the new LED lights in a month or two.
    Off-Grid in Central Florida since 2005, Full-Time since June 2014 | 12 X Sovello 205w panels, 9 X ToPoint 220w panels, 36x ToPoint 225w panels (12,525 watts total) | Custom built single-axis ground mounts | Complete FP2 Outback System: 3 x FM80, 2 x VFX3648, X240 Transformer, FLEXnet-DC, Mate-3, Hub-10, FW500 AC/DC | 24 x Trojan L16RE-B Batteries 1110ah @ 48v | Honda EU7000is Generator and a pile of "other" Generators | Home-Made PVC solar hot water collector | Custom data logging software http://www.somewhatcrookedcamp.com/monitormate.html
  • RichardU
    RichardU Registered Users Posts: 19
    Re: How to measure dedicated circuits

    Most of my lights are on a home automation system and I have them come on at 70%. Plus there's rarely more than a dozen or so lights on at any one time. I do have a scene which turns on most of my lights, but have never used it for more than a moment or two.
  • jcheil
    jcheil Solar Expert Posts: 722 ✭✭✭
    Re: How to measure dedicated circuits
    RichardU wrote: »
    I do have a scene which turns on most of my lights, but have never used it for more than a moment or two.

    Likely because you would be blinded or sunburned for 2-3 days afterwards right?
    Off-Grid in Central Florida since 2005, Full-Time since June 2014 | 12 X Sovello 205w panels, 9 X ToPoint 220w panels, 36x ToPoint 225w panels (12,525 watts total) | Custom built single-axis ground mounts | Complete FP2 Outback System: 3 x FM80, 2 x VFX3648, X240 Transformer, FLEXnet-DC, Mate-3, Hub-10, FW500 AC/DC | 24 x Trojan L16RE-B Batteries 1110ah @ 48v | Honda EU7000is Generator and a pile of "other" Generators | Home-Made PVC solar hot water collector | Custom data logging software http://www.somewhatcrookedcamp.com/monitormate.html
  • BB.
    BB. Super Moderators, Administrators Posts: 33,431 admin
    Re: How to measure dedicated circuits

    I put ~24 small 4" ~11 watt Halo LED cans (first I had seen with zero insulation clearance) in a small 3 bedroom California Rancher in the Living room, dining room, kitchen, bathroom, and hallway. In the Living room and kitchen, I put them on several switched circuits so I do not need to turn them all on at once.

    Attachment not found.

    Very happy with the results. The home is being rented right now, so no furniture but looks very nice in the evening (lots of light). Not too much light and no glare.

    I saw a Condo that did similar with standard 6" Can lights (I had replaced 120 watt filament with in CFL a few years ago). Not near as nice (LED look better and CFL were too bright--something about color temperature or similar made them almost uncomfortable to use--even on dimmers--just not as nice looking).

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • RichardU
    RichardU Registered Users Posts: 19
    Re: How to measure dedicated circuits

    I've been pretty happy with A19 screw in LED bulbs for my existing fixtures. They look a bit different if you stare at them, but no one ever does.
  • BB.
    BB. Super Moderators, Administrators Posts: 33,431 admin
    Re: How to measure dedicated circuits

    I did put a Costco screw in (smaller form factor) flood/spot type bulb in one fixture we use all the time a few years ago--And I cannot tell the difference (perhaps a bit more spot light than flood from the LED). I do not change the rest of the bulbs yet... Don't use them enough (and I still have excess power from my GT solar array at the end of the year).

    Prices are coming down--So probably will change out more next spring/summer.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset