Blues 2-1 and a transformer for halogen spots

Yesterday I attempted to replace a dumb switch that controls two halogen spots in my bathroom with a Blue 2-1 switch and ran into what seems like an electrical issue. It was wired for on/off single-pole load, with neutral wire and a ground. When I tested the switch by turning it on, both the switch and something in the direction of the spots (a transformer?) started making an angry buzzing noise, so I turned it off.

I replaced the old dumb switch back, but now I’m wondering: Are these spots not supportable by the 2-1’s? And if they should be supported, what could I have done wrong?

(Edit: I consistently misnamed the 2-1 switches; fixed now)

It could be an incompatibility with the transformer if those are low voltage halogens, but you would not think in the switch mode that would matter.

You have to separate Romex conductors in the switch box, correct? When you installed the smart switch, did you test to determine which 2-wire was the line in which 2-wire was the load?

I didn’t test which one is load and which one is line at the time of installation, but now that I opened it up again, I tested the wires and they were installed the right way around (line gets the hot wire, load gets the one leading to the transformer). These are low voltage halogen bulbs, so maybe an incompatible transformer is the issue?


What hub are you using? Post back with what parameters 258 and 261 are set to. Should be a value of 0/1 or disabled /enabled.

I’m on zigbee2mqtt. Can’t find the place where I can translate the “pretty” names to the numbers you asked for, so here’s the next best thing: a state dump as json.

    "action": null,
    "activeEnergyReports": null,
    "activePowerReports": null,
    "autoTimerOff": null,
    "buttonDelay": "0ms",
    "defaultLed1ColorWhenOff": null,
    "defaultLed1ColorWhenOn": null,
    "defaultLed1IntensityWhenOff": null,
    "defaultLed1IntensityWhenOn": null,
    "defaultLed2ColorWhenOff": 0,
    "defaultLed2ColorWhenOn": null,
    "defaultLed2IntensityWhenOff": null,
    "defaultLed2IntensityWhenOn": null,
    "defaultLed3ColorWhenOff": null,
    "defaultLed3ColorWhenOn": null,
    "defaultLed3IntensityWhenOff": null,
    "defaultLed3IntensityWhenOn": null,
    "defaultLed4ColorWhenOff": null,
    "defaultLed4ColorWhenOn": null,
    "defaultLed4IntensityWhenOff": null,
    "defaultLed4IntensityWhenOn": null,
    "defaultLed5ColorWhenOff": null,
    "defaultLed5ColorWhenOn": null,
    "defaultLed5IntensityWhenOff": null,
    "defaultLed5IntensityWhenOn": null,
    "defaultLed6ColorWhenOff": null,
    "defaultLed6ColorWhenOn": null,
    "defaultLed6IntensityWhenOff": null,
    "defaultLed6IntensityWhenOn": null,
    "defaultLed7ColorWhenOff": null,
    "defaultLed7ColorWhenOn": null,
    "defaultLed7IntensityWhenOff": null,
    "defaultLed7IntensityWhenOn": null,
    "defaultLevelLocal": null,
    "defaultLevelRemote": null,
    "dimmingSpeedDownLocal": null,
    "dimmingSpeedDownRemote": null,
    "dimmingSpeedUpLocal": null,
    "dimmingSpeedUpRemote": null,
    "doubleTapUpForFullBrightness": 0,
    "energy": null,
    "firmwareUpdateInProgressIndicator": null,
    "invertSwitch": 0,
    "ledColorWhenOff": null,
    "ledColorWhenOn": null,
    "ledIntensityWhenOff": null,
    "ledIntensityWhenOn": null,
    "linkquality": 255,
    "loadLevelIndicatorTimeout": null,
    "localProtection": null,
    "maximumLevel": null,
    "minimumLevel": null,
    "onOffLedMode": null,
    "outputMode": 1,
    "periodicPowerAndEnergyReports": null,
    "power": null,
    "powerType": "Neutral",
    "rampRateOffToOnLocal": null,
    "rampRateOffToOnRemote": null,
    "rampRateOnToOffLocal": null,
    "rampRateOnToOffRemote": null,
    "relayClick": 0,
    "remoteProtection": null,
    "smartBulbMode": 0,
    "state": null,
    "stateAfterPowerRestored": null,
    "switchType": "Single Pole",
    "update": {
        "state": null
    "update_available": null

I also took a video showing how the lights pulse/buzz: (neutral installed, verified load at the load terminal).

Thanks. I’m probably not the guy you want interpreting your zigbee2mqtt settings, but I do see that you have the relayClick=0, which should be P261, which is what I was looking for.

Just want to make sure the switch isn’t set as a dimmer. That may be in those settings but not labeled as such. Maybe output mode, not sure.

So let me ask you this. When you turn the switch on or off, do you hear the relay click? Not the paddle click, but a slightly deeper click that immediately (more or less) follows the paddle click.

258 is outputMode, and 1 is On/Off, so should be good to go.

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You sure it’s not supposed to be 0 for On/Off?

Pretty sure, verified mine is set to 0 and is dimming :slight_smile: and that’s what’s in the actual driver notes. @Eric_Inovelli can you update the config docs please?

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Pretty certain it’s in on/off mode. I used the local setting method (up and config x 3, see red led indicator) to ensure it was set to on/off, prior to even pairing it with my coordinator.

Do you hear the relay? See my question above. There are two on/off modes.

The relay click doesn’t do anything other than click the relay though :frowning: Even in on/off mode with relay click enabled, the power sent to the load is from the dimmer circuit, and isn’t a smooth sine wave, which may be the source of the buzzing.

At this point I’m just trying to confirm that the OP has his device with the click enabled. That’s about the best we’re gonna get.

I dont’ disagree with you that a less than perfect sine wave could cause the transformer to buzz. The design spec for this device is for it to use the physical mechanical relay when set to the mode we’re discussing. Theoretically, this should be the same as a dumb switch,

I saw the step in your scope screenshot labeled “Brightness 100/100”. Was that in the on/off mode with the relay clicking? Ideally, Inovelli should conduct their own independent testing to confirm the purity of the output.

At this point I’m just trying to confirm that the OP has his device with the click enabled. That’s about the best we’re gonna get.

Confirmed. I tried with and without the click enabled. Same effect.

Thanks. I can’t think of anything else to try. The settings you enabled should mimic a dumb switch, but apparently there is more to it.


No, that was in dimmer mode. I did test in on/off mode with the relay click, but since it was almost identical to the 100/100 screenshot, I didn’t take another screenshot. If I remember correctly, the power was on very slightly longer (like less than 0.1 ms) than when at full brightness in dimmer mode. Or maybe it was the other way around–power was on slightly longer in dimmer mode than in on/off mode. But either way, there was still a significant voltage jump as the dimmer circuit switched the power on, rather than being a smooth sine wave.

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A simple transformer might get upset. A transformer is coils of wire and any coil tries to keep the current flowing. The dimmer might be suddenly turning off the current path which does bad things when the coil is trying to force the current to continue.

The device is always dimming a little bit even when full-on and even when the relay is clicking. The power always goes through the dimmer circuit.

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In theory, in a neutral config with relay enabled, Inovelli asked for/expected the switch to be sending a straight sine wave through. I think Eric and team are looking into why this might not be the case since oscilloscopes are not showing this to be the case.

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It was a theory, but it’s not what happened in practice. The relay is being used to swap between traveler wires in a 3-way circuit with a dumb switch.

In theory this was to be an on-off or dimmer. In practice it is just a dimmer that can be programmed so it is either off or at full brightness.

I can set the Red to emulate an on-off and so it clicks when installed as a single pole with a neutral.

Right, but it was a switch requirement from the start. We’ll have to see whether this was a “missed the mark” thing with the manufacturer or whether it can be incorporated via firmware update.