I think my dimmers just blew up :(

As the subject says, the symptoms aren't looking too good, but hopefully someone here can offer me a glimmer of hope!

My CBus installation is about 3 years old, and consists of 3x8ch dimmers (w/power), 2x12ch relays (w/o power), 1 additional power supply, 1 pac, 1 cni, 1 pci, and a houseful of s2000 keypads.

I was just sitting here tapping away on my pc, and experienced a nasty power surge. UPS started beeping at me and my study lights dimmed down about 10%.

(My UPS didn't recover, and then spiked my PC, which now isn't booting. But another PC which was not plugged into the UPS survived without even a reboot. Go figure. But that's another story).

I went to ramp my lights back to 100%, but the switch wasn't responding. Nor were any other dimmer lights in the house. Relay lights not a problem. Went to the switch board, RCD looked okay, but reset it anyway and flicked the lighting circuits off for a few secs then back on. Over to the CBus panels, and I've got lights on the relays, PCI, CNI, Power supply, PAC, but with the dimmers, no-one's home

I figure there's two possibilities - either both my dimmers have been fried, or they're on a circuit of their own, and the circuit breaker has fried itself (does that happen?)

Regardless, I'm doubting it's a problem that I'm qualified to solve, so unless there is something else I can try to get my dimmers up and going again, are there any electricians reading this that can come to my aid in Melbourne's north (Preston?)


Thanks,
Mark.

 

Hmm.. after lying awake for another few minutes unable to let it rest til the morning, I decided to stick my multimeter into a power point. 188V. What the?!

That would explain why my UPS is still going crazy, but my other PCs (with 110-240V switch mode power supplies) are working ok.

Also explains why the lights dimmed down. So I'm guessing its just a matter of the relays being more tolerant of lower voltage than the dimmers?

I've called my electricity supplier, and am I've currently on hold with "high call volumes in the fault centre", so I'm hopeful that its a grid supply problem that will be fixed by the time I wake up in the morning.

Ok. Cancel that, lights just came back. Thanks for listening

 

The DIN Relay and Dimmer units have in-built monitoring of the condition of the mains voltage. Once they detect that mains is going down they shut off the outupts and store the current state to EEPROM (if enabled). 188V probably put the dimmers just under this threshold, meaning that they thought that power was failing, so they were probably sitting in shut-down mode.

The relays (w/o c-bus power) were probably very close to doing the same thing, but the subtle difference in thresholds caused by having a different type of power supply, meant that they were working, but probably only just.

 

Thanks for the explanations guys.