Blue Series 2-1 Firmware Changelog | VZM31-SN

Blue Series switches are not compatible with magnetic transformers… that is an inductive load.
You need to read the manual before installing the switches in locations where it would be considered a motor inductive load.


The magnetic ballast uses a magnetic transformer of copper windings around a steel core to convert the input line voltage and current to the voltage and current required to start and operate the fluorescent lamps.
Ballast used to create high voltage for short period and increase the total impedance of the circuit while working. Transformer step up or step down voltage throughout the period.
Step down transformer is not a motorized load, not a ballast…
Obviously you can find any fine print to explain any issue. Like with any drug advertisement - they are all created just to cover producer behind.
As a matter of fact. it worked perfectly fine with 2.08, (with Leading edge). The issue started with 2.14, when firmware changed to trailing edge
Now, why there is no issue with halogen bulbs? Why no buzzing with “3-way Dumb switch” mode, no problem with “Single pole Sine wave” mode (except annoying click sound)?
I bought 2 dimmers first to check with my set-up, before buying another 20 dimmers. Everything was great before moving to 2.14.
Needless to say, no problems with Insteon, Zooz, Lutron.
I already expect reply - use Insteon, or Zooz or Lutron - Inovelli just not for you :slight_smile:
I believe the most reasonable explanation was from Eric_Inovelli is about difference between Leading and Trailing Edge chopping mode. I believe that Trailing Edge just have much more abrupt edges. “In the case of leading edge chopping, when NMOS is turned off, the induced voltage is less than 100V. In trailing edge chopping mode, when the NMOS is turned off, DTU1 generated the induced voltage Vmax-250V

Waiting for firmware update.

Hi @vladimir.korobov, as some have mentioned we don’t support using the switch with an inductive load. Full sine wave mode and 3-way dumb mode (as this will switch it to leading edge) will likely be ok, but we can’t say that it is supported because of the different load types and different customer setups. In the next firmware version full sine wave mode will be the default and leading edge the default after that. You will only be able to enable trailing edge mode to increase compatibility with LED bulbs with a configuration setting or button combination.


But it IS an inductive load


Hi @EricM_Inovelli
As you well know, LEDs are designed to run on low voltage (12-24V), direct-current electricity.

An LED driver rectifies higher voltage, alternating current to low-voltage, direct current (because LEDs intensity (in lumens) is a function of current. The most efficient and commonly used way to control the brightness (dimming) of LEDs is to use “Pulse Width Modulation” or PWM, in which the LED is repeatedly turned “ON” and “OFF” at varying frequencies depending upon the required light intensity of the LED
I am referring to the drivers within LED fixtures or LED bulbs.
pwm light control
Where I am going with that - any LED internal driver is reducing voltage from the line voltage (120V) down to 12-24 V depending on type of LEDs (CREE, Nichia, Osram, Lumileds etc. almost all of LED chips are GaN with yellow phosphor), so there are several major type of most efficient (high power factor) drivers:
Buck Converter (or variants: Inverted Buck converter, Buck-boost) or Flyback Regulators. The point is that any Buck converter has inductor and any flyback has a transformer. They are just embedded in the LED bulb or fixture. Flyback is the most efficient, robust and highest quality driver, but is expensive comparing with Buck

Buck convertor with inductor:

Flyback regulator with transformer in CCM (continuous conduction mode)

Bottom line - claim that Blue 2in1 series is not compatible with inductor or transformer is almost the same as saying that this dimmer can’t work with any LED light. This is different comparing with motors, CFL ballasts etc.
As I’ve mentioned before, at the moment I am replacing LED MR16 bulb with Halogen MR16 50w bulb, buzzing and flickering is gone.
Again, waiting for updated FW with Leading Edge mode


Regardless of it working under a previous firmware version is irrelevant. Even if TE vs LE changes are the cause of the overheating issue, it’s also not relevant.

The switches are not safety rated for motor inductive loads or transformers. This was stated in bold print even in the beginning.

Even if it works on v2.08, there’s still a chance of a failure, smoke, or even worse - fire. Your home owners insurance won’t cover it either if it’s something you did yourself. It’s best to use a properly rated switch. The internals of a switch rated for transformer, outlet, or motor inductive load use are completely different than one rated for lighting only. There’s a reason for this. The price to create a lighting only switch is much less in materials and safety rating costs.


Give me an example of ANY LED driver without transformer or inductor. How you can transfer line voltage to LED voltage (12-24V)? See my previous post

No offense, but do you understand basic thermodynamics?
When you step down a voltage, you create heat. It is inductive.

An LED is not stepping down 120V to 9-12V. That’s not how an LED works.

An LED driver is NOT a transformer. Transformers convert an input voltage to an output voltage while both functioning on an alternating current (AC).
LED drivers convert AC to DC and supply a constant current to the LED.

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Sorry to cut in. Now I’m wondering about my setup due to this discussion. I have a transformer that turns 120v ac to 24volt for a low voltage light strip.
Would that be considered an inductive load or not suitable for the blue series? It’s something like this product :

You can repeat this as much as you can about relevant or not this is the FACT. You are specialist in reverse engineering - take any LED bulb, reverse engineer it and find any without inductor or transformer.
The point is the the peak voltage spikes (as mentioned by Eric) which are different in these two modes.
And if we are talking about difference between transformer and inductor:
(The Difference Between Inductors and Transformers - Shreejee Electronics)

Dimmable 120V LED bulbs are designed to behave like resistive loads regardless of the voltage of the internal LEDs. A transformer for low voltage lights is not.


They don’t use an inductor nor a transformer.
The terms you are using are not exactly correct.
I explained the difference in my above post.
LED drivers convert AC to DC current. Completely different.

I’ve actually built custom LED bulbs before. :slight_smile:

I understand you are frustrated but please, I advise you not to use improperly rated switches for improper use. Safety is a very important thing, don’t take it lightly.


How? You just use resistor as a voltage divider? What was you efficiency and power factor LOL
You did it as hobby, I was in a company that was developing LED drivers for most of the bulb manufactures

I appreciate you concern about my safety…

Built them for a company actually. I would say, but I’m still under an NDA.
My main point is that an LED driver is not the same as a transformer.

So in other words, this is not a suitable use for the blue series? Is there any setting in which I could power a 24volt low voltage light strip and use the blue series as an on off switch, safely?

One way is to get a zigbee controller on the 24V LEDs (gelopto is an example) and place the switch on a different circuit that doesn’t have inductive load and use binding between the two to turn on/off

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TY. Are there any Inovelli or other smart switches that you know of that can be directly connected to a 24 volt transformer?

Also, just to clarify, a product like this which says it is compatible with any dimmer is actually not safe to use with blue series?

Quickly glancing at the description, that one actually looks like it’s supposed to behave like a resistive load and be safe to use with any dimmer.

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