RBgrid

Guides ·

You think the well pump is starting more often than it used to

  • Tested on firmware v1.1.7
  • Intermediate

A well pump doesn't ask. It starts when the pressure switch tells it to, usually in a basement or a well house where nobody is listening, and it stops again. Owners notice the change rather than the thing itself: the pump seems to run more often than it did, or the sound is different, or the electricity bill moved and nothing else in the house changed.

That observation is worth measuring, and this guide is about how to measure it. It is not about what the result means. The numbers below will show you what your pump draws and when it ran; what a change in that pattern says about your pump is a question for whoever services it.

What you need:

  • an RBgrid hub, on your home Wi-Fi;
  • the pump's circuit reachable by an rbAmp module — either at the board the pump is fed from, or at the pump itself;
  • if the pump is in a building or a basement the hub's I²C cable can't reach, a remote node: a second ESP32 with its own rbAmp modules, reporting to the hub by radio. On v1.1.7 a hub takes up to 6 nodes, 4 inputs each (Remote nodes).

Safety. For any work inside an electrical panel, call a qualified electrician.

1. The one thing to get right before you buy

🔑 A node records energy only if one of its rbAmp modules measures voltage. With current-only modules a node still sends live current, and closes no energy records at all — so you would see the pump running and never see what it used. For a pump node, buy a single-phase rbAmp set with voltage measurement.

Two more, both cheap to get wrong:

  • An original ESP32. The node firmware is built and tested for the original ESP32 with 4 MB of flash and no PSRAM. The S2, S3 and C3 are not built or tested, and the one in your drawer is probably an S3.
  • A node is flashed over USB, and has no over-the-air update. So put it somewhere you can still reach with a laptop. A well house is fine; the inside of a sealed enclosure behind the pump is not.

The hub itself needs Wi-Fi for this to work at all: ESP-NOW is the Wi-Fi radio, so a hub with no network has no radio for its nodes either.

2. Will the radio reach the well house?

The only honest answer is that you try it, and the trying takes ten minutes before you mount anything. Pair the node on the bench, carry it to where it will live, and read the link while the pump actually runs — that procedure, and the three numbers it gives you, are in pairing a remote node.

Two things to add for a pump specifically:

  • Read the link while the pump is actually running, not while the house is quiet. A motor starting is the moment a marginal link shows itself, and it is the moment you care about.
  • One fallback belongs at the top of the list for this job and usually gets skipped: meter the circuit at the board instead of at the pump. If the pump has its own breaker in a panel the hub can already reach, you don't need a node at all — you need one clamp on that circuit. A node exists for the pump you can't reach that way, not for every pump.

The rest of the fallbacks, in the order people try them, are in the same guide. I'm not repeating them here, because a procedure explained in two places drifts in one of them.

3. What you will see, and what you won't

This is the part to read before you draw conclusions from anything.

RBgrid gives you two views of the pump, on two different timescales:

  • Live values, every 3 seconds — current, power, power factor. This is where you watch a start happen: open the point and run a tap until the pressure drops.
  • Energy records, one per 15-minute period — how many watt-hours the pump used in each period, kept as history and priced at your tariff.

⚠️ There is no per-start event and no cycle counter. RBgrid does not log "the pump started at 03:14 and ran for 40 seconds". Nothing counts starts, times a single run, or records a run's peak. If you have read that a monitor will tell you how many times your pump cycled, that is not what these figures are.

So how does "it seems to start more often" become something you can look at? Through energy per period, and through your own eyes on the live view:

  • A pump that runs more in a given 15-minute period puts more watt-hours into that period. Compare periods with each other, and compare this week against last.
  • A pump running when the house is asleep shows up as energy in night periods, which is the comparison people find most telling, because nobody is drawing water then.
  • Watch a start live when you can make one happen. The running draw settles within a few seconds, and that settled figure is the one to compare over weeks.

And the limit of the live view, stated plainly: readings arrive every 3 seconds, and energy is totalled per 15-minute period. Don't read the live number as a measurement of the pump's starting surge — a motor's inrush is a fraction of a second, and these figures are not built to resolve it. If you need the start current itself, that is a clamp meter and an electrician, not a monitoring system.

4. Put it on its own point, and name it

In Management → Points, bind the node's channel as its own point and name it before Home Assistant or anything else ever sees it. One point for the pump, nothing else on that clamp: a figure that includes the pressure tank's controller, or the pump and the garage lighting, answers a different question than the one you asked.

On v1.1.7, history is kept for up to 12 measurement points, and a node's points come out of that same pool rather than adding to it — so the pump is one of twelve, not a free extra. Points past twelve still show live values; they just keep no history. (Which loads are worth a history slot works through the choice.)

🔑 If you also meter the sub-panel the pump is fed from, pick one. Meter either the sub-panel or the loads inside it — not both — or the hub's "unmetered" remainder subtracts the pump twice and reads too low. Your house total is unaffected either way: totals come from the supply point, not from adding up the lines.

5. What the hub does when the well house goes quiet

A node is a sender. It holds its own clock from the hub and closes its own 15-minute periods, so a dropped link doesn't lose the measurement immediately:

  • Up to 8 periods — about two hours — are held in the node's memory, then the oldest is lost for good. When the link comes back, those periods arrive late and land in the hours they belong to: energy is filed by when it was measured, not when it arrived.
  • A power cut at the node is different. The queue lives in RAM, so a node that loses power loses the held periods and the period in progress. There is no gap marker in the history to tell you afterwards — which is worth knowing before you power the node from the same supply you might switch off.
  • A node that boots while the hub is unreachable closes no periods at all until it has heard the hub once, because its clock comes from the hub.

⚠️ Out of range and powered off look the same to the app and the API — both are simply a node that stopped being heard, 15 seconds after its last frame. The hints are in the shape: a weak link usually flaps, with lost packets climbing first; a power cut is a clean drop with good numbers right up to it.

The node card shows signal strength, lost packets and when it was last heard. There is no signal or loss threshold in RBgrid, and I'm not going to invent one for you. The honest instruction is the simple one:

watch that lost packets stay at zero and the node stays online while the pump is actually running. If it does, your measurement is trustworthy. If packets climb or the node drops when the motor starts, deal with the link before you read anything into the numbers.

What this doesn't do

  • It does not tell you whether your pump is in trouble. RBgrid measures electricity. It names no fault, owns no threshold, and has no opinion about your pump. If you have searched this subject you will have met the phrase "short cycling" and a set of wattage figures that supposedly settle it; those are claims about pumps, from people who are not us, and we are not going to repeat them as though measurement made them ours.
  • What you can do is show someone a pattern instead of a memory: what the pump drew, in which 15-minute periods it ran, how this week compares with last. A plumber with a chart is better off than a plumber with "it seems louder".
  • No start counting, no run timing, no peak capture — see §3.
  • No alerts. Nothing watches the pattern for you or notifies you when it changes; you look, or you pull the data over the API or as CSV and watch it yourself.
  • RBgrid switches nothing. It has no outputs and no relay. It will never turn your pump off, which for a pump is the right way round.
  • A node doesn't do three phases. On v1.1.7 a node is single-phase only, with no phase grouping — a three-phase pump in an outbuilding is not covered by a node today. At the board, the hub meters three phases perfectly well.

Next