Wifi relay three phase power supply problem

(Bernardino Morillo Merino) #1

I have installed 3 wifi relay devices in a installation.

Everyone works fine for 2 or 3 switches, but then they stop to work.

Led light still working, and wifi menu and it is not burn.

Supply voltage is 250V (three phases installation), and I disconnected them and reconnected in a 230V but they don’t work.

I can hear relay opening and closing but really really quiet (“click”)

I don’t know how to solve it, if I change the relay or not, and why happend that.

The relays lines are for lighting and no more than 10A, so I discarted over amperaje.

Any help?

(Martin Harizanov) #2

I’d start by checking the wiring to make sure the units are connected correctly. Make sure that you are not shorting anything.
These are very high quality relays, I don’t think you can burn them easily:

If the PSU looks operational, it is most probably something in the relays or the relay driver. If you can post close up pictures of the board, that may provide visual clues

(Bernardino Morillo Merino) #3

Now they are working again, but only disconected of the 250V and connected to 230V

I don’t understand nothing.

I can open-close them by http using the own wifi of the sensor

I am using them only by HTTP control, any problem with that?

(Bernardino Morillo Merino) #4

The relays work fine the FIRST TIME after that the not open-close and “click” sounds very quiet

I am totally lost now

Capacitors problems?

I am testing them connecting only to power, without relay conections


(Bernardino Morillo Merino) #5

Is there any incompatibility with 3 phases supplies?

Lighting lines are 250V from a 3 phase supply


(Bernardino Morillo Merino) #6

The boards are totally perfect

I guess it is something related with relay inside or software


(Bernardino Morillo Merino) #7

Very close pictures of one of the wifi relays boards. In my opinion are totally perfect.


(Bernardino Morillo Merino) #8

(Bernardino Morillo Merino) #9

Still researching.

Relays works perfectly all if I power them directly 5V throug a supply to the pins

Now i am again totally lost.

It must be HTTPs control or onboard supply.

(Martin Harizanov) #10

Can you detach the board from 230V completely and power it with 5V from the FTDI header? Check if relays behave as expected. That will eliminate PSU issues. If all works fine when powered from 5V then the PSU is damaged and not providing stable 5V. Do you have multimeter or better off oscilloscope?
again: mind and respect 230V AC

(Bernardino Morillo Merino) #11

I have measured that:

  • 5V supply perfect
  • Relays running perfect
  • Now I have 2 relays totally working, I don’t know how exactly, after relays tests with 5V supply.
  • Now I have 1 relay with a problem, when I switch it through http the LED blinks once (a milisecond) and then switch off automatically.

I didn’t test FTDI header. I will try now


(Bernardino Morillo Merino) #12

Ok I have restore the bronken one,

Only with the reset botton.

Now they works fine again, but I have invest all the evening in that and I still without any information about why they doesn’t works with a 250V line. I have some options:

1- HTTP control doesn’t connect properly, even with the proper line
2- Capacitor problems. Sometimes the relay tries to move, but the income voltage is low (LED bright very much)
3- Onboard power supply problems with 250V
4- A weird automatic cnfiguration or something I don’t know yet of the menu or settings.

Relays are perfect and board in general doesn’t have any problem.

I will learn how to work with MQTT and learn how to set wifi menu in all the settings.


(Bernardino Morillo Merino) #13

Finally the problem is related to power supply.

With FTDI 5V supply they work perfectly. Maybe one of them have one second delay, but it is reasonable

Finally i will solve my problem including a external power supply of 5V in order to avoid over voltage and wiring at 5V, I prefer that in fact.

I recommend Martin to develop one relay with only 5V supply, it is easier to solve and probably it will be cheaper and thinner.

Thanks for all

I will send more info with the final solution and tests.

Best regards

(Bernardino Morillo Merino) #14

The last question

One of my relays do something strange.

When I feed them through 5V external supply everyone works perfect but one reboot wifi connection when I switch OFF the relay. The blue led freeze for a second and I can’t switch on for 2-3 seconds.

It only one of them, the other 2 work fine, Any advice?

(Robert Wall) #15

What type of load is it switching - resistive or inductive? Do you need a contact suppressor across the contacts?

(Bernardino Morillo Merino) #16

The loads are inductives because of the 12V power supplies for the LEDs

I don’t understand the other question. I only need to cut the hole line, not partially.


(Bernardino Morillo Merino) #17

Ok, I don’t have a contact supressor as you mentioned, I need one, I am pretty sure now. Any recommendation?

(Bernardino Morillo Merino) #18

How to introduce them, I don’t know any example

(Bernardino Morillo Merino) #19

Ok, I am seeking diode.

What about this?


(Bernardino Morillo Merino) #20

I am a bit lost with the diode problem, it seems to be finally my problem, How to solve it Martin?