Beiträge von Doghouse

UPDATE

Finally resolved the issue with Shelly 2 Dimmer blowing D1 & D14 (IN4007) twice!

With fantastic help from thgoebel and doing some further testing. The Shelly 2 Dimmer does appear prone to high voltage inductive spiking. Nothing showed while using a digital volt meter when devices on the same power line were switched on or off. Closer inspection using a mains analyser I could see HF spiking of >300v on the line when devices were switched on (or off) I assume this was the root cause these diodes fail on the Shelly 2 Dimmers (poor diode response time to HF spiking).

I have since fitted a small two stage mains filter prior to the dimmer which has totally eliminated all signs of spiking on the mains line to the unit, replaced the Shelly 2 Dimmer with the Shelly Dimmer Gen3 which also has additional mains filtering built in. Hopefully this is the end of fry ups! watch this space

Hi,

Looked on Amazon and found these diodes, It doesn't say if they are UF4007 diode's. 100 pcs (£7.05)

100 PCS Fast Recovery/Ultra Fast Recovery Diode 1kV 1A 500ns SOD-123FL F7

Can't seem to find UF4007 diodes with a F7 package?

Any help would be great please

A great reply and superb pictures, thanks for your replies as always.

Would you suggest changing D1 and D14 to the UF4007 diodes on both Shelly 2 Dimmers and Gen3 units just out of safety and reliability reasons. After two units destroyed by these poor response diodes and the fear of a possible fire hazard to my home this should be done?

I connected a mains analyser to monitor to my mains supply in my shed which has a fairly long run of armoured cable (30mtr) from the house. It shows L-E spikes and E-N spiking when my shed light is switched on or off (4ft fluorescent tube) or any electrical units like a garden strimmer, not sure why this is happening???

Many thanks for your great help..

Oh no... Yet another Shelly 2 Dimmer bites the dust!!

This is the second Shelly 2 dimmer in just over a month of replacing it that has blown exactly the same way with D1 and D14 spectaculary going short (No load on at the time) Yet I have other units that have not failed in almost a year

What is the root cause of this? As I understand this may be due to poor response time of the mains input diodes IN4007's or is there some other reason??? This is worrying and have growing concerns with other units around the house that could go the same way with the possibility of a potential fire in my home while away.

My mains supply is stable, I don't live in a rural area where mains fluctuation is a problem. Would a small mains filter be of help?

Shelly have offered a replacement it under warranty with a Gen3 dimmer, but not sure if this has faster response diodes (UF4007) or not, shelly won't respond to my question if this is an underline issue with the Shelly Dimmer 2.

Any help woul be so much appreciated

Regards

Roy

Yes understand that other parts may have been damaged by the arcing, just seems sad to throw it out and fit another (typical engineer) I still don't know why it blew in the first place. You mentioned spikes, but in the UK the supply mains is fairly constant. No other units popped and still function fine, but why these use slow responde diodes in the first place if this is a weak link.

Maybe just bad luck

Thanks again for the help

R

Thank you for the kind response Thoebel,I hope this gets back to you... A superb answer as to why my unit may have failed. If I try to replace these diodes with faster response ones, could you advise which would / could be fitted. I've cleaned the unit and hope by replacing these diodes I can shed life back into it.

Kind regards

RM

Hi All

First time here in the forum and wanted to ask if anyone has had issues with the Shelly Dimmer 2 going bang without any demand on the output load

I've taken apart my unit and see on the (L) and (N) input lines there are two diodes which apear to rectify the incomming mains supply to one point on the PCB.

D1 has completely exploded causing all the soot inside all of the unit, Diode D14 on the neutrial side (N) appears short circuit, which may have been the cause of the failure to the Dimmer in the first place.

Has anyone here had the same issue? I'm just concerned as I've several of these units running on HA around the house and now worried of a fire while away