8Channel Dimmer flashing on and off

Today the downlights on one 8Channel dimmer module began to flash on and off constantly sometimes at random intervals. The NEO wall switches are unresponsive and displaying no led. I turned off the power to the CBUS module but when i connect it back on the dimmer module begins to flash all 8 channels on and off in 1 second intervals. Ive had the system installed for 5 years without a problem just wondering if the reason would be apparent to anyone. The system comprises of 1x PC Interface, 4x 8Channel Dimmers, 2x 4Channel Relays however i only have the PC Interface and 1x Dimmer module connected to the house atm and thats the one playing up, thanks

 

Since the NEO has no LEDs, that problem is probably related to lack of power on the bus. Bus power would come from one or more of the Dimmer or Relay units which incorporate a mains power supply. If a dimmer supply was barely sufficient to power the dimmer itself, but not the C-Bus network, you might see this sort of behaviour. Perhaps the power supply has been damaged by a voltage transient? Sometimes switchmode power suplpies like the type used in C-Bus DIN units can fail in a way that causes them to turn on and off at regular intervals.

If you have more dimmers or relays that you know incorporate power supplies, do they operate correctly on their own? If you use the other units with power supplies, do you get the LEDs lighting in the NEO? If they do, I suggest that you might need to replace only the dimmer that is flashing.

 

What have you got?

Hi T666
you say

no info on the qty of switched or PIR's or else, But then you say to cotradict the above

which if it is the case, as Don points out you've probably got too few power supplies, resulting in low voltage that the bus cannot operate. Also keep in mid the burden & clock, different model's integrate these differently.
In any fault finding scenario, always look where the most recent changes (any work / modifications) in a building that have been done in the first instance. Weather electrical work or not this often catalyst for issues.

Hope we can help further

 

Similar problem

Hi ,
have had similar problem on 3 x 1 amp 8 ch dimmers on 3 different jobs ,
they seemed to pulse on and off , swapped them out and all has been fine since .
Regards

Conor

 

Hi sorry i did not check my post after the initial problem was resolved by replacing 1x TED70 Atco transformer to a down light that had gone out a few weeks prior to the blinking issue. After replacing the transformer the whole system went back to normal.

However now i have an even worse problem 3 months later.

Hopefully someone can give me some insight so i can narrow down what might be wrong here. Last time I feel like I just flooked it by replacing a transformer.

Last night, all cbus power sources automatically turned on, every light and fan in the house went on. The neo wall switches show only the on states for zones that were on prior to the issue. While the leds on the switches are responsive i can click them on and off, they do nothing to control the lights or fans. At the board every dimmer and relay module has all led indicators forced to on. They are not blinking this time they are solid on and they are unresponsive to click. I had to flip the power off to the cbus board to turn them all off. One abnomily is of the dimmers, the second dimmer in the board is not effected. This module is not forced to an on state and the leds are responsive. I can control the lights in that room from this module.

If someone can make sense of this let me know. I have since removed the transformer that seemingly cause the issue last time and just terminated that power cable. That did not help this time. The one environmental factor is it rained very hard here yesterday and perhaps there is moisture somewhere?

The other thing i have a question about is the breakers and power supplies. For example I bought 1x pc interface and 1x dimmer with a power supply, and 3 others dimmers and 2 relays without power supplies, however they are on 2 seperate breakers from the main board. So perhaps this is an issue?

In summary all worked for 5 years, then 3 months ago had the blinking issue, and last night full power on mode to all dimmers and relays (except for the 2nd dimmer).

My cbus system comprises of:

16x Neo Wall Switches E5052NL- 686

main board 16amp breaker >
8amp breaker > 1x PC Interface + 1x 8 CH Dimmer L5508D1A
8amp breaker > 1x 8 CH Dimmer L5508D1AP ( the only module that works)

main board 16amp breaker >
8amp breaker > 1x 8 CH Dimmer L5508D1AP + 1x 4 CH Relay L5504RVFB
8amp breaker > 1x 8 CH Dimmer L5508D1AP + 1x 4 CH Relay L5504RVFB

35w downlights have Atco TED-070 transformers. Each zone has no more than 4 transformers connected to it


Thanks David D

 

I don't think your transformers have anything to do with the issue, since this is on the output side of the dimmer, whereas the symptoms you have been describing suggest a problem on the control side of the system, i.e. the C-Bus side.

The action of turing all the loads on at once is most likely caused by the Remote Override On being activated somehow. The green & green/white pair of conductors, when shorted to C-Bus negative, will cause all loads in the dimmers/relays to be turned on. Under this condition you should see the Unit LED on the output units blinking at approximately 1Hz and all the channel indicators on the dimmers/relays turn on.

It sounds to me that you have a wiring short in your C-Bus network somewhere, that is allowing the remote override to inadvertently be activated.

 

Ummm.. I hate to state the obvious but I would be looking at if you have sufficient power being supplied to run the cbus network..

Flashing led indicators on switches and random control are classic symptoms of not enough juice on the cbus..

Quick calc:
16 x neo switches @ 22mA = 352mA required
1 x L5508D1A @ 200mA supply = 200mA Supply
1 x L5508D1AP @ 0mA supply
1 x L5508D1AP @ 0mA supply
1 x L5508D1AP @ 0mA supply
1 x L5504RVFB? @ 0mA supply
1 x L5504RVFB? @ 0mA supply

If this is all your network consists of you are considerably underpowering cbus..

Cheers,
Nik

 

Update

Replaced my 8 ch dimmer and all is now fine , just added original ga to new dimmer so I assume it was a fault in the dimmer , had this on 2 customer sites as well replaced dimmers there as well and all is well there , all dimmers were all around the same age .
Cheers conor

 

Check the environment

Hi David
Thanks for the informative post, it really helps put us in the picture and best be able to assist you.
Your transformer replacement last time was a co-incidence, it did not fix the problem as it is not causing it. The problem is being caused on the C-Bus 36V side of the network, not the 240V mains side.

If the part numbers are as you state, the 2 x L5504RVFB do have power supply (the B is a suffix for a lower relay current model: 10A for resistive but only 1A for fluoro, previously deleted / no longer in the range)
so if that's the case you have 3 x 200mA power supplies, that is more than adequate to supply the network as you describe.

It sounds to me like a C-Bus power issue, most likely caused by a shorting at a terminated cable end (but still could be a concealed damaged cable). As it is happening intermittently, the rain may be the culprit. e.g. when it rains heavy some water is getting into the wall box behind one switch, and manages to short the un-terminated white & green cores of one cable. That could explain why part of the bus remains active, while the rest are all hard on. But you have had a lot of rain recently (you poor wet buggers, send some down to SA!). Maybe it's only happened went you've had a particularly heavy downpour that has caused some water to penetrate your building when usually it is ok. Or maybe it is only from a certain direction.

You don't mention any PIR's, as they would be the first places to check. If there is anywhere in your building that has a moisture problem check around that area. If not you may have to check each neo switch input, try external walls first.

 

Hi thanks for everyones suggestions,

The above symptoms are accurate, for 3x dimmers and 2x modules the Unit LED is flashing while the channel indicators are unresponsive and ON.

However there is 1 dimmer not effected (the 2nd dimmer L5508D1AP), the Unit LED is solid ON while the channel indicators are responsive and working properly.

If there was a cat5 short somewhere in the system should all the dimmers be effected?

Is there some explanation for why this 2nd dimmer is not effected while all the others are?

From each neo wall switch the cat5 is run independent back to a HUB where they are all looped, and a single cat5 goes into the pc interface and chained to each module until the last one terminated with the clipsal stop plug to end the chain

Just to note with the wiring of the cat5 to each neo switch, only the blue,yellow (-) and bluewhite/yellowwhite (+) are used, the green and greenwhite, brown and brown/white are not connected to anything.

I believe all the internal cat5 cabling through the house and wall switches is dry and un damaged, theres just no way for any water to get near em, BUT the HUB that loops them all together is directly below a roof fan. You can see the roof fan above because i have not finished the ceiling here, and not ducted the fan yet, and i did notice 1 drop of water just to the right of the HUB. It was literally 1 drop lol. This was back on the day that it really rained hard. So perhaps 1 drop has landed right on a connector going into the hub and fried a cable? It should have dried by now but the problem is still here. I have just been using normal lamps for lighting for the past week. This is the only place i can think of being the source of some moisture. Its been working like this for 5 years tho, i should have put something over the hub just to be safe anyways but yeh its like been through worse storms before without even a drop coming through

 

It is possible that this particular unit has a fault and the remote override function is not working correctly. If this unit is at the end of a Cat-5 run it is also possible that there's a break or bad connection in the patch lead that goes to it or a bad connection on one of the connectors at either end of the lead.

The short between the remote override on conductors and C-Bus negative could be just about anywhere. It's entirely possible that, if the hub loops all 8 conductors together, that the short is out behind a switch somewhere. To remove this possibility you could always cut the green/green-white conductors in the Cat-5 run that heads out to the switches. For a bit of belt-and-braces you could also replace the 8P8C connector (RJ-45 plug) on the run that goes to the dimmers & relays and just terminate the 4 C-Bus conductors (blue/blue-white and orange/orange-white), trimming the remote override conductors (green/green-white and brown/brown-white) back to ensure they can't touch anything.

 

Sorry just read your response in full, same as newmans

Problem RESOLVED (well partially)

steps:
1.
I unpluged every cat5 input from the front of the HUB leaving only the cat5 that runs from the HUB to the PC interface and the problem is still there

2.
I unpluged this cat5 at the input of the PC interface, and bang, all dimmers and modules operate as normal!

So the problem is related to this cat5 going from the hub to the pc interface, or the hub itself?

As i had unpluged all of the cat5 coming the wall switches at the front of the HUB and the problem was still there i dont think the issue is to do with those cables or power issues with the neo switches, so perhaps water has dropped onto one of cat5 modules in the back of the hub that loop all the inputs on the front together and that is the issue.

I ran a backup cat5 cable from the HUB to the PC Interface so ill try that out tomorrow to see if just changing that cable fixes things, otherwise im assuming its one of the cat5 modules in the HUB

Its good to have narrowed down the issue it seems either 1 cat5 cable or the hub itself

Ill let you guys know what happens

Thanks David D

 

on the way

Hi David
Good to hear you are making progress.
The star cabling (individual cable to each switch) install sounds a little different than what we're used to seeing. What type/make/part no is the HUB? Can you post a picture? I assume from your description it must be an active device, not just a patch panel with all sockets connected in parallel.

Ragards
Matthew

 

sorry i haven't done anything since last time im still turning the lights on/off in the house from the modules lol.
its a clipsal titanium 24 port hub cp5e, ill get some photos tomorrow of the hub plus the cbus boards. and will test that cable between the pc interface and the hub
i do have one quick other question tho. regrading the pc interface, i no longer have a rs232 port on my computer, could i use a rs232>usb or a rs232>rj45 cable?

 

Yes, you can use a USB <-> Serial converter with the RS-232 PCI. I'd recommend the ones from Dontronics that use the FTDI chipset as these have one of the better emulations of true RS-232 ports.

 

cool thanks man ill get one of those.

i put some photos on my fbook. i pretty much put the system together myself but the cbus technical line was really helpful at the time there was a guy called anand who helped me alot. all the wiring was done by my dads electrician but it was the first time hes worked with cbus so it might not be 100% how u spose to wire it. let me know if looks ok or need some changes. still the ground floor isnt wired into some of the modules and ill get beter photos soon.

http://fbcdn-sphotos-a.akamaihd.net/hphotos-ak-ash4/396945_416967711688083_1276335465_n.jpg
http://fbcdn-sphotos-a.akamaihd.net/hphotos-ak-prn1/561202_416975148354006_1784906536_n.jpg
http://fbcdn-sphotos-a.akamaihd.net/hphotos-ak-ash4/251979_416977971687057_1414133660_n.jpg

i still havnt resolved the override function issue yet, im yet to test if its the hub or the cat5 cable from the hub to the pcinterface but i will next week, and ill put more photos on my facebook soon too. i prety much built the house house if anyone wants to add me just add me on http://www.facebook.com/daviddeitchiii

 

I assume that the device you have plugged all the pink C-Bus cables into is an un-powered patch panel, and not an Ethernet switch or an Ethernet hub?

 

yup i cant see any power to that panel (clipsal titanium 24 port hub cp5e) should that be a pwered hub?
the black panels below are for the home network but i think they are unpowered too.

 

Certainly not. Whilst C-Bus uses 8P8C connectors like Ethernet it is entirely different. Plugging C-Bus into a powered ethernet hub or switch may well let the "magic smoke" out of something.

 

Hi David
As Newman says, the equipment your c-bus cabling is running through is an (un-powered) RJ45 patch panel. While it may physically perform the function of a "hub" it is not usually referred to as that, but a "patch panel" as that is the function it gives. A "Hub" in networking world is typically an active Ethernet device.
Your install looks fine, maybe a bit over engineered, much better that than dodgy . I would say it's been done by a commercial data experienced electrician, not a cottage/domestic experienced electrician.
Anand was an excellent resource, (NSW CIS/Clipsal were certainly the poorer without him) he would have steered you in the right direction.

Just have to find that bad cable/ connection and you'll be back on track.