Lighting increasing and appliances blowing?

Good Evening,


I have a client for whom we have just completed a full rewire within a small commercial unit with a single-phase supply. The coffeeshop/bar opened eight weeks ago and since then has had several issues, including the following;


1. Lighting is fed via a four-way MK dimmer module, increasing in brightness intermittently.
2. A laptop charger stopped working. Once investigated, it was reported to be due to a power surge,
3. An amplifier for the audio system is going into standby mode due to a potential surge.
4. The coffee grinder is cutting out halfway through use.


The distribution unit is a Schneider with all separate RCBO circuits. The faults are intermittent, and none of the breakers tripped from the above. The lighting circuit is fed with one feed and distributed via two dimmers, both affected by the increased brightness.
I checked all the usual culprits, like loose connections, and the EIC had nothing suspicious to report. Can anyone please help me with understanding what is going on here?

Kind Regards,

Andy

  • On the dimmer subject, I use nothing but Varilight items - the rest, including Knightsbridge, Click etc are rubbish.

    Stuff not working - is it simultaneous? Or random? Agree about logging for a period, but is it something silly like an appliance being switched on which is triggering the events you describe? The coffee grinder thing is interesting - Am guessing it has a hefty motor which will create some disturbance when initially switched on.

  • Hi Andy,

    Thanks for the reply. There is no SPD fitted, and as you said, it will only protect from high voltage; I spoke to Schneider about this, and they do not sell anything protecting from low voltage anomalies. It seems to be a good bit of advice about recording the voltage over a long period. I believe by hiring a Fluke 1736 tester and recording the voltages over time, then I can send a report back to the DNO.

    Before that, I will complete an EIC again to ensure I have not missed anything for the third time; I will also replace the main incoming fuse and check the carrier for erosion, etc.

    Andy

  • Thanks, JP; No surge protection. I will check the voltages again when I retest the install.

  • Thanks for the reply. I agree the Varilight dimmers are good, especially with the low-voltage circuits. 

    The faults occur randomly, as I did think it could be the coffee grinder creating some sort of a surge, but I believe the appliance has been checked and used in other shops with no faults reported.