SurgeProtector Strange behaviour

[SuperCapacitor]

Hi.

I am having a bit of trouble with a device I manufacture. When plugged directly into the mains it operates perfectly fine with no issues at all. This has been the case for for the past 18 months.
Recently i have had a couple of returns where the device acts strange.

I dont want to give away all the details due to it being a commercial product and anyone can read this.
The device has a built in isolated PSU that powers 2 microcontrollers and an LCD display with touchscreen. One of the microcontrollers control a Triac via an opto triac.

So on a straight up mains supply it operates as expected no issues for the past 18 months. However when plugged into a surge protector it takes minutes to start up. When it does eventually start up then it restarts every few minutes.
If using the very cheap surge protectors the LCD displays controller is damaged and will not respond to any commands from the microcontroller.

I have spoken to Masterplug about this and they have no idea why its happening. I find it odd that they work flawlessly until plugged into a surge protector.

One such unit was returned as the LCD display was not responding. after establishing the surge protector being plugged in i replaced the LCD and returned the device. That same device has run flawlessly now for over 12 months.

Is anyone able to shed any light on possible causes as myself and Masterplug are both stumped as to the problem.

Thanks in advance.

 

[Alec_t]

IF the surge protector includes an inductor and IF your circuit draws a rapid burst of current I guess it's possible that a back-emf voltage spike is generated which gets through to something critical in your circuit?

 

[SuperCapacitor]

I am told by Masterplug that in their protectors they have only 3 MOVs the more expensive model has a Suppression diode included.
My device is a dimmer so it is plausible that it could draw rapid bursts of current.

Would this back EMF be able to get past a transformer and 2 regulators with smoothing caps? Would it also be able to disturb the power supply so much that it stopped the microcontroller starting up?

If it is then how can i go about stopping it from happening?

 

[AnalogKid]

Is the surge suppressor information secret also, or can we get the manufacturer/part number/schematic/whatever?

ak

 

[SuperCapacitor]

I dont have any information on the surge protectors, not schematic wise anyway. For obvious reasons the manufacturer isnt going to just hand me the schematics for their devices.

Im just going on ifs and buts at this point.

Googling surge protector schematic i see a lot of variants, from simple MOVs across the live and neutral to multiple MOVs with resistors and inductors.

 

[(*steve*)]

You should probably get someone to characterize your device's power demands both with and without the surge protector.

 

[Alec_t]

Would this back EMF be able to get past a transformer and 2 regulators with smoothing caps? Would it also be able to disturb the power supply so much that it stopped the microcontroller starting up?

Who knows?
Since we don't have a schematic of either the surge suppressor or your device we're working with both hands tied behind our backs .

 

[Arouse1973]

You need to tell us about your device, I have tested many surge suppressors to lightning levels. You need to be a bit more open about your product.
Adam

 

[Arouse1973]

Who knows?
Since we don't have a schematic of either the surge suppressor or your device we're working with both hands tied behind our backs .

I have a 007 key to release you