Dimmer circuts turning on themselves

Hi All

We have installed our first lighting system in a small domestic house using 1A and 2A dimmer packs controlled by standard 4 button switches and 1 DLT. The problem is that at various times of day 3 of the circuts will turn themselves on without user input and will stay on until the user turns them back off. All 3 circuts are in one area of the house (Kitchen) but are on different dimmers and relays. Any ideas what could be causing this.

Another quick question is about a 2A dimmer pack "L5504D2A". We installed and commisioned a system in another house with all working 100% and when we returned to show the occupier how to use it 2 months later one dimmer pack was completely dead with no lights lit anywhere on it. All outgoing circuts are protected by 1A & 2A MCB's. Any reasons for this to happen and can it be repaired as it is out of warranty

Any help would be appreciated

Thanks

 

When unexpected things happen on C-Bus the first thing to do should always be to use the C-Bus Diagnostic software to look at the C-Bus messages. This will tell you where the messages are coming from.

 

Turning on lights without user inputs

Hi All,

We also had a same kind of a problem,in the Cbus installation in the factory premises.Some particular lights are turnig on at various times of day and acoding to the maitenance crue some are at the "sundays"of the circuts will turn themselves on without user input and will stay on until the user turns them back off.
Situation seems bit funy and hard to guess at all,what the problem exist there.
Can any one pls help on this matter.

Regards..
Madhawa

 

The C-Bus Diagnostic software has the ability to log the network traffic. By looking at the network messages at the time of the lights turning themselves on, you'll be able to determine why they are turning on.

 

Lights never go on by themselves. Although it is common for people to report that this is happening, there is always a good reason for why they have done it. It could be that there is a PIR switching it on, or a Schedule or Logic switching on the light. It could even be something as simple as a security guard switching on lights and forgetting to switch them off.

I once discovered that the cause of a similar problem was a touch screen that was running some test schedules. It had been locked in a cupboard and forgotten about. Within a few minutes of using the C-Bus Diagnostic software, we discovered that the messages were coming from a touch screen, then they realised what was going on.

I also recall a case where a child was sleep walking (or maybe just going to the toilet when very sleepy) and was switching on lights at night then leaving them on.

As Newman suggested, use the C-Bus Diagnostic Software log to see when the light came on, and which C-Bus unit the message came from. Once you know that, you will know where to start looking for the cause.

So for example, if you are looking for when group 32 came on, you might see a message like:

11:08:47 Rx : Source Unit 5, GA 32 On

This tells you the light when on at 11:08 and that unit 5 sent the message. You can then use the Identify function to find out what type of unit address 5 is.

If you have PICED, then read the Advanced C-Bus Fault Diagnosis document (C:\Clipsal\PICED_4_7_1\Manuals\Advanced Fault Diagnosis.pdf). If you don't have PICED, then download it, because it is the best thing since sliced bread

 

I bet that was first reported as a software bug

I read that the term "bug" was originally used with computers after an insect caused a problem. From Wikipedia:

 

I have the best bug story about C-Bus and it happened about 6 weeks ago.

One day very very early in the morning the beautiful bride got out of bed at about 4.30am to go to the toot. She came back to bed complaining that she could smell an electrical burning smell.

I got up (under protest) to investigate the issue. I noticed the smell as I walked through the hallway. I walked into the dining room to notice the rear outdoor porch light was on, however the key input unit adjacent to the door and in the same view as the light showed that the C-Bus channel was OFF. Now even though it was 4.30am I knew this was wrong - after all, I installed all the C-Bus and programmed it years ago.

It gets better, the light seemed to be dimmed somewhat, this was odd because it was connected to a relay unit. I pressed the key input to turn the channel on and the light went to 100%. I turned the channel off and the light dropped to about 50%, now it's 4.30am and I am not very smart at the best of times, but this was not right.

So, my mind turns to each aspect of the install, this is a brand new 1.5mm twin and earth tps run from the relay channel to a single light over the rear porch - what the hell could be going wrong ???????????? And what is with that electrical burn smell ????

So here we go, down stairs get the bloody ladder, get the bloody torch and back up stairs to the man hole in the bloody bathroom to get up into the bloody roof. (Sorry about all the bloody's, but remember it is 4.30am in the morning.) In the roof I crawl along the "new" cable run to the rear porch light doing the big sniff at a frequency of 2 sniffs per second. No evidence of cable damage and no electrical burn smell to be found.

So I crawl out of the roof and make my way back to bed. Did I mention I was now about 10 minutes to 5am ? I nestle back into bed only to have the bride say "I am worried about this"

OK OK OK - I get back out of bed and trudge outside to shut down the light circuits in the meter board, only to get back inside and find the bride was so so worried that she is now sound asleep. I get back into bed and try to relax, the whole light dim on the relay channel issue still does not compute but bugger it, by now I have the ****s.

This is a really really really long story so I hope you have some time.. In the morning (when the sun came up) I had to compute if this was all a dream or if it was real. The lights are not turning on so the bit about turning off the light circuits and for that matter the rest of the story must not have been a dream.

Now it gets even better again. The air conditioning kicks in and we can smell a really bad and warm electrical burning smell. Ah Hah ! it was not the C-Bus it was the A/C (still doesn't explain the he whole light dim on the relay channel issue). About 1 year ago the outdoor A/C condenser unit ( the big box with the big fans) burned out its run capacitor and it stunk. So the fan coil unit in the ceiling must have a similar problem. So here we go again - down stairs get the bloody ladder, get the bloody torch and back up stairs to the man hole in the bloody bathroom to get up into the bloody roof, open the fan coil unit and find the bloody run capacitor. (Sorry about all the bloodys) the run capacitor is relatively small compared to the condenser unit. A relatively cheap 6uF unit. Off to heatcraft and buy a new one. I am not really sure if this is the problem but the AC is 10 years old and I can't think of anything else.

Well long story short, well not that short, it was not the run capacitor. So off I go with the sniffing device at 2 Hz. The electrical smell is concentrated near in the middle of the upstairs hall, in this area is the AC return duct (important for later info) as well as the C_Bus panel in the nearby linen press cupboard. I can't work this whole thing out, and the now isolated rear porch light switch wire on the C-Bus relay unit is still worrying me. I decide to change the old relay unit for another spare.

The replaced relay unit works fine, the light behaves as it should and the smell has gone. The problem is everything changed at once and I am not really sure what the problem was. I chucked the old relay unit in the bin and decided to move on with my life - did I mention - the light seemed to be dimmed somewhat, this was odd because it was connected to a relay unit ?? Even though the relay unit was in the bin and I had moved on this bit was nagging me.

I have to finish this as there is a 300Mb limit to posts. A week later on a quiet Sunday afternoon the outstanding question got the better of me. I grabbed the old relay unit and started to dismantle it. After about 20 minutes of bashing and crashing ...... I uncovered the circuit board of the relay section in question, to find a cricket had found its way into the unit and had its body across the big solder lugs for the relay contacts / load. It turns out that when the channel was OFF the current was traveling through the cricket's body, when the channel was ON the current traveled through the relay contacts as normal - hence the 100% - 50% situation early that morning. The cricket and the circuit board he was fused to, was starting to burn - Just as well I turned of the lighting circuits at 10 to 5am.

Turns out also that the smell from Mr Cricket was getting sucked into the AC return and warmed up by the FCU which made the AC really stink. I am so glad I decided to pull the relay unit apart otherwise this would have been the 9th mystery of the world.

Now that is a great C-Bus "bug" story, and it is bloody, bloody bloody true...

 

Bloody hell mate, what a stinker

 

That is an awesome story!

 

Brilliant story Mr. 555 !

I just remembered another story of lights doing odd things.

We had a report that lights would "go on and off at random by themselves". This seemed hard to believe so I went to site for a look.

There was a conference room with a series of different scenes for different situations, all stored in a C-Touch and triggered from a key input unit. The installer rapidly pressed the scene keys, firing off about 20 scenes within just a few seconds. The C-Touch processed the scenes and sent out all of the commands in the queue over a period of 10 seconds or so. During this time, a lot of the groups changed states (for the different scenes) and this was described as lights doing random things all by themselves

There is now an FAQ topic "C-Bus Command Queue" which explains how it works.