So a week or two ago I had my gas hot water heater tank replaced by a heat pump water heater (HPWH). It was hooked up to a dedicated 30A/240 circuit using an available double slot space in my panel. I asked the installer to route the wires from the HPWH through the installed CT clamps to the breaker. I have to explain here that back when sense was first installed, we were not physically able to clamp to the bus for whole house, so the installer bundled all L1 and separately L2 wires to the breakers together, and put a CT clamp around each. That worked as intended although be it a little messy (but dictated by the situation).
Today I was comparing my utility’s reported net usage and it does not add up vs. the data I have from sense (it always did before that install date). The utility reports more net usage than I have through sense. I opened up the panel to verify he had routed the wires, as requested. They all apear to be running in the same direction through each CT and likewise he routed all wires going to the bottom connection on each double breaker together etc. (in other words it does not appear he combined L1 and L2 wires in the same CT).
I switched the breaker to the HPWH off and then on again a little while later. The sense meter shows nothing changing. The delta between the sense solar production and consumption as about 300 W larger than what the utility meter reports. That difference would be what the water heater is consuming right now. If I look at the deltas for past days comparing utlity report with sense, the differences are pretty much all explained by the energy consumption that the HPWH itself reports through its own cloud connection.
Anyone have any ideas why things are not being picked up, or what else to verify?
You mention that the bottom connection on each double breaker are routed through the same CT. Depending on the posisition of the breaker in the panel, the bottom connection could be L1 or L2. You can check this by measuring the voltage from bottom connection to bottom connection. If they are all the same you should see zero volts. You might see a few volts which is OK, if you see 240 volts that one is through the wrong CT.
This was ac very good suggestion, and I should have thought of it myself. I attach pictures of the left and right side breakers. The top-left double is the new water heater. He used a white wire were I would have expected red (is that a code violation?).
Ignoring the white red, you can see the left side is full with only double breakers with each one having red on the bottom lug, black on the top. Measured all potential differences between all tops and all bottoms and they are (close to) 0. So far so good.
On the right side things look a little different in that, from bottom to top, there is: double, single, double, double and double. Measuring voltage between red on the bottom-left side of the panel and all the reds on the right side shows all 0, except… the second double from the bottom, where I measure 240. Considering there is a single slot “jump” right above the bottom double, which has red on the bottom, I would expect all doubles above the jump to need to have red on the top, which they do, except the one.
So I am thinking that when they installed the new HVAC as well, they must have disconnected the wires to the outside unit (which are attached to that exact double breaker), and hooked them up in reverse. No idea why they would have taken them off, but it seems like the explanation.
You can also see from the pictures that literally all red wires (including the one white) are through one CT and all black through the other. So this mismatch causes one black wire through one CT to be in the wrong CT, and one red one as well.
I am planning to fix as follows:
Throw main breaker
Pull that one double breaker out of the panel
Reverse wires on that breaker
Push it back in
Throw main breaker to on…
Any disagreement, or other suggestion? It is much harder to re-route the wires through the CTs and it seems to my that the reversed L1/L2 hookup on that breaker is confusing to anybody due to coloring standards?
Thanks, I decided not to go ahead and do this myself since I just recently had the work done on the HPWH and the HVAC and still waiting for city inspection. I don’t want there to be any opportunity for finger pointing at/after inspection. So I contacted the installer to come rectify things. That means waiting a few more days, but avoids problems down the line.