Rako lighting systems

[stalkera]

Any of you guys and girls out there work on Rako lighting systems?

 

[plugsandsparks]

Come across them every now and again. Whats the issue, Rako have quite good tech support if you just need some help,

 

[stalkera]

Come across them every now and again. Whats the issue, Rako have quite good tech support if you just need some help,

Thanks for coming back on this. 1st I agree, they do have good tech support. I think this is more of a man on the ground type job.

Basically I keep get fuses blowing in the old style toroidal transformers (though the lamps are LEDs) and the RCD trips. Though I don't know if the blown fuse is tripping the RCD or the other way round.

 

[plugsandsparks]

Can you upload a pic of the dimming module which is blowing fuses. I have had units blow fuses and the units can be sent back to Rako for repair. Need to make sure that your loads are balanced so you dont have too much lighting on one channel. You may also have a fault on the cable from the unit to the lights, again easy to test. Most electricians should be able to deal with this, its not the programming side which requires their software, just checking the loads and wiring, which is what any electrician can do. If it is the unit that is faulty, the old ones just have dip switches (if the unit needs to be repaired) when it comes back just remember which switches were in what position (photo it) and which cable goes to which channel.

 

[stalkera]

This is system - I think its fairly new.

I realise that there are several (8?) modules per box - but I don't think this is the problem as several circuits started doing this at the same time after being stable for well over a year. The lighting is well spread out over the circuits, but several different switchplates are in control of the same circuit - think of landing switching ++. Could this be causing the problem?

 

[plugsandsparks]

"I keep get fuses blowing in the old style toroidal transformers"

Where are the fuses that are blowing ?

No problem with several switches operating the same light.

Is the issue (s) confined to ccts on the same module or across both modules, also how are the modules powered from the "fuse box" one cct or two , a photo of the fusebox showing the lighting cct MCBs and RCDs will also help.

 

[stalkera]

Hi,

the real fuses are in the transformers, you can make them out at the top of the case 3.15a slow blow.

Its the RCB that runs the Rako boxes that is tripping. I wondering if it is the indictive load that is blowing the fuses when RCB trips?

 

[Avo Mk8]

Also in each transformer box as well as the fuse appears to be a varistor surge limiter in series with the toroidal transformer, which is there to reduce the inductive surge. I don't believe they are prone to fail short-circuit, but that might explain the tripping and fuse blowing. Rako could maybe confirm if this is a known problem, and supply replacement parts?
I don't see any residual current breakers, only MCB's.

 

[plugsandsparks]

As AVO mentioned, there is not an RCD in the fusebox you have photographed , this looks like a sub board off your main fuseboard ? where there may be an RCD, if it is the B10 MCBs that are tripping this makes sense if the fuse is also blowing, however i am confused about the role of these transformers , are they remote from the Rako kit as it looks like the actual lights are commoned together on the output of the transformers.

Dont suppose you have the Rako project file to hand ?

What i would have expected is that each lighting zone is connected to an output directly of the Rak dimming unit. So do these transformers work for just 2 zones, if so, and the lamps are LED , i would be looking at removing them and installing the appropriate dimming LED driver to replace these transformers.

Again a call to Rako will confirm whether these transformers are appropriate for this installation. I suspect not

 

[stalkera]

Also in each transformer box as well as the fuse appears to be a varistor surge limiter in series with the toroidal transformer, which is there to reduce the inductive surge. I don't believe they are prone to fail short-circuit, but that might explain the tripping and fuse blowing. Rako could maybe confirm if this is a known problem, and supply replacement parts?
I don't see any residual current breakers, only MCB's.

Hi Avo Mk8,

thanks for joining in here. You are correct re the MCB - and it is the unit 1 switch that is tripping. There is an RCD upstream of this but this is not tripping. I will try Rako, about known problem with old skool toroidals. However the "boxes" have WML-300 dimmers (for leading edge dimmable loads) which are intended for inductive loads. TBH - I was planning to replace them with modern drivers anyway. In any case they had previously been working happily for over 12 months .

 

[stalkera]

As AVO mentioned, there is not an RCD in the fusebox you have photographed , this looks like a sub board off your main fuseboard ? where there may be an RCD, if it is the B10 MCBs that are tripping this makes sense if the fuse is also blowing, however i am confused about the role of these transformers , are they remote from the Rako kit as it looks like the actual lights are commoned together on the output of the transformers.

Dont suppose you have the Rako project file to hand ?

What i would have expected is that each lighting zone is connected to an output directly of the Rak dimming unit. So do these transformers work for just 2 zones, if so, and the lamps are LED , i would be looking at removing them and installing the appropriate dimming LED driver to replace these transformers.

Again a call to Rako will confirm whether these transformers are appropriate for this installation. I suspect not

Yes. Correct re the MCBs blowing and it being a sub-board off the main RCD unit. The lamps are 12v retrofit MR11s and hence need the transformer (one per circuit each with around 9 lamps), there were halogens previous and hence the transformer is a bit over-clubbed for the LEDs. There is one WML-300 dimming unit per transformer. Yes I am planning to change the drivers for something more modern - but there seems to be Rako-phobia amongst the local sparkies - do you do jobs in London? I renamed the project file as a jpg as otherwise I can't upload here - hopefully that works.

 

[stalkera]

As AVO mentioned, there is not an RCD in the fusebox you have photographed , this looks like a sub board off your main fuseboard ? where there may be an RCD, if it is the B10 MCBs that are tripping this makes sense if the fuse is also blowing, however i am confused about the role of these transformers , are they remote from the Rako kit as it looks like the actual lights are commoned together on the output of the transformers.

Dont suppose you have the Rako project file to hand ?

What i would have expected is that each lighting zone is connected to an output directly of the Rak dimming unit. So do these transformers work for just 2 zones, if so, and the lamps are LED , i would be looking at removing them and installing the appropriate dimming LED driver to replace these transformers.

Again a call to Rako will confirm whether these transformers are appropriate for this installation. I suspect not

You are correct, it is the MCB that is tripping - there is an RCD upstream, but this seems to be fine.

I do have the project file, but the website only allows JPGs (I did rename - but it rejected the whole message!).

Each zone/circuit has its own transformer (powering several lamps) and its own Rako WML-300 dimmer (for leading edge dimmable loads). These are the right ones for inductive loads and were working fine for over 12 months until this suddenly started happening.

I am certainly interested in replacing the toroidal for something more modern but the local sparkies I have spoken to seem Rako-phobic, which is the main reason I came to thee forum. Do you do jobs in East London?

 

[plugsandsparks]

No i dont work south of Rugby, thats why i was trying to advise remotely -

You have a couple of options change all the MR11s for 240V GU10s dimmable and ditch the transformer altogether, trick here is to make sure the dimmable GU10s match the existing dimming module in the Rako.

Another option is to change the lamps to 350mA constant current type, rewire them into series and install a dimmable constant current driver in place of transformer (this is generally how its done as it solves most compatability issues and most drivers i have found can handle leading or trailing edge and give very good dimming range and minimal flicker

Change transformer to dimmable 12 V driver, keep existing lamps.

Either way its less of a Rako matter and more matching lamps to drivers and drivers to Rako leading edge dimming module. If you dont want to change the Rako in any way you can solve this with lamps and drivers.

BTW, are you actually dimming these lamps or are they simply on/off ?

AVO's point about the in-rush device expiry could be why they are failing now but TBH i have never connected Toroidals to electronic dimmers just never felt right

 

[plugsandsparks]

Just occured to me that these lamps could be in a bathroom or en-suite which may be why they were kept at 12V in the first place, if so, its almost certain that option 1 converting to 240V lamps wont fly due to regs.

 

[stalkera]

There isn't much space in the ceiling void height (hence I suspect the original use of MR11s) - also the lamp wiring isn't earthed, does this matter if I upgraded to 240v GU10s (ex bathroom)?

I was leaning towards the dimmable 12V driver and leaving the lamps in parallel - but as you mentioned it, does the series approach tend to have less compatibility issues?

Rako suggest that their leading edge dimmer modules work with LEDs, but I might have to switch to t/e if they flicker too much. TBH I don't use the dimmer much except I think 37% which was the lowest I could go on the current set-up.

Now I know more about this, I'm rather surprised that the installers didn't mention about switching out the toriadals when they installed the system - which is kind of reason I'm looking elsewhere now!

 

[plugsandsparks]

Lack of earthing on those lighting ccts is not ideal but in reality you will be looking at double insulated GU10 fitting which do not have provision for an earth connection. However BS7671 recommends earth provision for the future, just in case the fittings are changed for Class 1 (i.e. requiring an earth connection) - TBH it would not stop me doing for myself, by now i would have got the GU10s in scrapped the transformer and experimented with different makes of lamps to get the best dimmable action. It really is trial and error, the main issue is that lamps do fail and are constantly changing manufacturer and design , they are generally getting better but for commercial / non domestic applications the 350mA constant current lamps, simply do not suffer from these issues as the dimming is done by the central driver, not the lamps and Tridonic for example have a great range of drivers and they are very good. So if i want good dimming control, no hassle in the future i go down this road. The last rako i did had the RAK 4 dimmers, early version of yours, and i had a mix of 240V GU10s and 350mA for bathrooms and low level lights / picture lights. The RAK4 did a pretty good job with the GU10s once we got hold of the appropriate lamps. I think but cannot be sure RAKO recommended the lamps, they may not do this anymore but i ordered a shed load and left surplus with client for replacements as and when.

There is plenty of info on-line for the lamps in question, OSram, Megaman, Luceco etc etc for Gu10s
The dimmable lamps need to be stated as suitable for leading edge but as time has gone on, they had got better.

 

[davesparks]

You have a couple of options change all the MR11s for 240V GU10s dimmable and ditch the transformer altogether, trick here is to make sure the dimmable GU10s match the existing dimming module in the Rako.

I'd want to know what the outgoing cable is before recommending a change from ELV to LV. That cable may not be suitable.

 

[plugsandsparks]

TBH, there are a number of "things" that need to be checked, not least where the lamps and cables are going.
All my recommendations are based on helping the Op get an electrician in rather than a Rako specialist.

To the OP, DS is questioning the voltage rating of the outgoing cables from the transformer, you may be lucky and find markings on the cable denoting its characteristics, however at no time am i suggesting you DIY the solution just that its doable for an electrician with no rako knowledge

 

[stalkera]

Thanks for your help on this plugsandsparks and AVO (I think my old man has one of those in the leather case somewhere - from the time when lights were lights), much appreciated. I'll let you know how I get on.