C4 Panelised Lighting – Electrical Scope (UK)

[Cumulus]

Hi,

Apologies for the wordy post/question, but I think that I need to give some basis for the question  . . . . 

I am just about to go out to tender for the Main Contractor to build a new house in Aberdeen, UK. In principle, I have decided to go for Control4, but at the build stage, scope will be for lighting only. (A structured cabling infrastructure has been included in the MC’s electrical scope and I am comfortable with specifying & designing that myself).

 However, I want to install a C4 panelised lighting system to control around 24 “smart” lighting circuits (a few C4 Zigbee switches will be included too). At this point, the architect is preparing the drawings to include with the MC tender package and we are working on the principle that the Contractor’s electrical scope will include wiring of the lighting loads back to the C4 lighting panel for commissioning by the C4 vendor. I just need to be able to accurately describe the Contractor’s electrical scope and get clarity on the split of responsibility between the MC and C4 vendor.

I had been working towards finalising the C4 scope with a C4 dealer, and based on discussions to date, I had believed that he would have been a good choice for me to do the panelised lighting supply and install etc. However, due to the current Covid situation, staff furloughs/shortages and lack of resources, he has just declined to be involved on the basis that he cannot provide adequate support at the moment. To some extent, this reflects well on him as a dealer in that he does not want to commit to a project that he cannot adequately resource, but on the other hand, it leaves me a bit “high & dry” in that I have to complete the bid package documentation as a matter of urgency without the C4 dealer being on board.

I don’t need people telling me that this is a bad idea, I do need some help from C4 Panelised lighting experts in the UK who can help answer a couple of specific questions on wiring panelised lighting in the UK to meet the requirements of BS7671:2018 (the “IEE Wiring Regs”). A replacement C4 dealer will be appointed in due course, but I have a little more time to do that once the MC has been appointed.)

So, for Panelised lighting installations in the UK, can someone help with the following queries please ? . . . .

 

Install & Testing

How are the LV supply & load cables marshalled in the C4 lighting panel? For example, would the electrician just wire to, say, DIN rail mounted terminals, with panel wiring to the C4 dimmer modules done by the C4 dealer/installer, or would all the panel LV wiring be done by the electrician, including connection to the lighting module terminal blocks?

This has implications for testing as the MC’s electrical team would be responsible for testing the LV wiring. Demarcation between electrical and C4 scope at the DIN rail would be neat, but the C4 dealer may not want, or be qualified, to complete the LV wiring but having the electrician test up to the C4 module input terminals is likely problematic – meggering the C4 module is probably not a good idea! Would having the electrical contractor only test as far as the DIN terminals before his final termination to the C4 modules be acceptable?

RCDs

30mA RCDs are pretty much mandatory for final circuits in the latest issue of the Regs. What are the implications of this for C4 panelised lighting? Does each output from the C4 dimmer module require its own RCD or would a single RCD on the line input to the C4 lighting module be adequate? Obviously, my preference would be for the latter with 3 RCDs needed as opposed to one on each load circuit (24 RCDs).

If a single RCD per module was installed, would it provide RCD protection for the 8 channels (as required by the regs)? Is there any C4 documentation that covers these details for a UK electrical installation? Alternatively, what guidance can be provided to the MC’s electrical team to confirm that a single RCD would meet the wiring regs (assuming of course, that it did)? I really don’t want to have to install 24 RCDs in the C4 panel (even supposing that there was enough space?) but I fear that there might not be a way around it?

 

I would really appreciate it if a UK C4 dealer/installer with electrical expertise (e.g., Part P registered) could help me with these queries so that I can get the MC tender document completed.

For the next stage, I would also like to hear from C4 dealers who would be interested in taking on a new project in the Aberdeen area. Initial scope would be Panelised lighting with a minimal C4 system to be included at the build stage (VAT exempt), post completion, additional C4 scope would be added (subject to VAT) to include AV switching and distribution.

Regards

Dave

[tdougray]

im sure @Crustyloaferwill be able to help you, I’m sure he’s in Scotland so give him a message. Super knowledgeable and so helpful. 

[SMHarman]

The panel has wiring blocks that the HV primary conractor wires to and can test to.  

The loads into that block will be on the RCD, so only 3 needed, or based on load calcs fewer still as potentially all 3 dimmer packs could be on one breaker. Here in the US my lighting panel loads are on a single breaker for the panel. 

You are overthinking the RCD and dimmer pack. You would not be asking if each light switch or dimmer in a traditional wiring structure needed their own RCD, centralizing doesn't change the current flow.  Just the location of the parts. 

The panel has a HV side (250) on the left and LV on the right to meet with electrical code.