Refrigerator Circuit Anomaly

Yes, that’s allowed too - up to 50 m² of floor area served per radial.

But we’re going OT.

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Yes, my IoTaWatt and all CTs are located inside my load center. The two CTs in question are about 1 foot apart.

Correct, the A leg does not show any part of the mystery load. It just shows the AC cycling on and off and a standby load of about 15 watts.

My load center is on an exterior wall, facing inward. I believe the wire goes down into the crawlspace, across for about 15 feet, and up an interior wall behind the refrigerator. As much as I would like to avoid it, I believe it is time for me to put the tone generator back on that circuit and trace the wire across the crawlspace to make sure it does not branch off anywhere and that the wire is undamaged.

The crawlspace was definitely a damp location before I bought the house a year and a half ago and put a dehumidifier down there. I will admit that the dehumidifier has not run consistently since then. The plug would occasionally fall out of its socket on the crawlspace ceiling until I installed a new outlet a few months ago.

I am guessing there would be physical signs of a 1500 watt discharge sustained over 14 hours. I will meticulously inspect all visible parts of the wire from the load center to the refrigerator for anything unusual.

If I don’t turn up any evidence of a problem with the circuit wiring then I will head over to the IoTaWatt forum to explore the possibility of hardware or software faults.

I think that more or less rules out anything external influencing both c.t’s/both inputs except for a common current in the cables they’re sitting on.

Hopefully a very stupid question:

And which circuit is that on? (Not that one of those is likely to account for 1.5 kW.)

So there’s a real possibility then that the wires do go somewhere else that you don’t know about. If a discharge is confined to a small area, then surely you will see it. If it’s distributed (don’t ask me how that could be), then it’s going to be a lot harder to see something.

Hi, sorry to be late to this discussion, but in the beginning you say the 14hr trace ends in a strange pattern. I quite often see that pattern of 3 short bursts at the end of long periods of consumption - when my Nissan Leaf battery reaches fully charged.
My Leaf here in the UK normally would draw 2500 watts from a low-spec house circuit, but it is possible to dial the car down further so that it charges at about 1500 watts.
So looking at your scenario from the other end of the telescope, is there any chance that an EV was being charged on that circuit at that time? 20kWh is an unremarkable amount of energy to be dumped into an EV.


Now that’s a very useful piece of information. Thank you.

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That’s it! Not only was there an EV charging but it was a Nissan Leaf! Well done, recognizing that termination pattern! It never crossed my mind that an EV could be charging on the refrigerator circuit.

I went out of town that day with my colleague who parked his Leaf at my house. We plugged it in to an outdoor outlet using a portable level-1 (120v) charger to keep the level-2 (240v) charger open for my wife’s car. That outlet happens to be fed off the refrigerator circuit. I must have had the sensitivity set too low on my tone generator when I checked that outlet last week. I just double-checked it today and confirmed that it is indeed fed from the refrigerator circuit.

Thank you you all for your help in determining that:

  1. The mystery load was almost certainly a real load
  2. It must have been outside the thermal envelope of the house
  3. My refrigerator is not on a dedicated circuit as required by the electrical code
  4. The mystery load was a Nissan Leaf charging up!

I can relax knowing that the mysterious 20kWh of energy was not a random and dangerous discharge but intentionally went somewhere useful. Again, thank you all.