Gauge Wire for Lighting Comms Cabinet?

[CaptainJack88]

I'm putting together a comms cabinet that will house all my automation for lighting. As a quick overview, the wiring currently looks like this (yes, I know the earthed switch wire is missing):

Sparky is dealing with wiring in the lights and switches, but I need to hook up inside the comms board for the automation part.

Does anyone know what gauge wire I should use for:

• 100A DP Switch to Live Terminal
• Live Terminal to Home Automation Dimmer
• Dimmer to Live & Neutral Terminals

I'm having a look on RS Components, but there's so much to choose from and I'm not sure which is the type I need

 

[Deleted member 18243]

The size of the cable will depend on the size of the MCB, which will be determined by the size of the circuit's load. Once you know the cable size, use that size throughout the circuit.

RS is probably the most expensive supplier available! Try Superlec for small quantities of electrical components.

 

[CaptainJack88]

The size of the cable will depend on the size of the MCB, which will be determined by the size of the circuit's load. Once you know the cable size, use that size throughout the circuit.

RS is probably the most expensive supplier available! Try Superlec for small quantities of electrical components.

Thanks, I didn't actually mean to put MCB there as its just a 100A DP Switch since its already behind one.

 

[Taylortwocities]

The 100A figure on the switch is just the maximum rating of the contacts and has absolutely nothing to do with the actual load!

If you have domestic lighting rig who's load appraches even a tenth of 100A, you need to have a serious rethink.

In fact, why do you think you need a 100A switch
*HINT* add up the total of those things on your drawing that you call "devices"

 

[333rocky333]

What size is that cable feeding into the main switch and what size is the Mcb before that switch.

A 100 amp main switch is likely the cheapest Din rail mounted device capable of providing Double Pole isolation, so I dont see a problem with that

 

[CaptainJack88]

The 100A figure on the switch is just the maximum rating of the contacts and has absolutely nothing to do with the actual load!

If you have domestic lighting rig who's load appraches even a tenth of 100A, you need to have a serious rethink.

In fact, why do you think you need a 100A switch
*HINT* add up the total of those things on your drawing that you call "devices"

It's the cheapest DP Din Rail switch there is. The circuit isn't pulling 100A. Not sure why you think this is an issue?

I'm going to "assume" (without doing any calculations here) that as each Dimmer has 6 LEDs or max 5m of LED strips on them, that 1.5mm wire inside the cabinet is sufficient

What size is that cable feeding into the main switch and what size is the Mcb before that switch.

A 100 amp main switch is likely the cheapest Din rail mounted device capable of providing Double Pole isolation, so I dont see a problem with that

It's a 2.5mm lighting ring cable. Basically there are 2 lighting rings, and I'm putting this comms box before them so I can neatly have my HA setup on them. In theory, I could just stick the dimmers inline on each lighting circuit, but it's not as neat nor accessible.

 

[333rocky333]

Assuming that 2.5mm is protected by a 20 amp max Mcb then my choice would likely be Tri rated 1.5mm its not cheap but nice to work with and best used with bootlace ferrules.
https://uk.rs-online.com/web/p/switchgear-tri-rated-cable/8034225/

 

[Taylortwocities]

I wasn’t saying it was an issue, but you would be surprised how many people see an amp rating on something and presume that it will provide an over-current capability.

Not bring picky, but domestic lighting circuits are almost always radial, not ring final circuits.

 

[winston1]

It's a 2.5mm lighting ring cable. Basically there are 2 lighting rings, and I'm putting this comms box before them so I can neatly have my HA setup on them. In theory, I could just stick the dimmers inline on each lighting circuit, but it's not as neat nor accessible.

Firstly lighting is not on rings.
Secondly lighting is not (usually) wired in 2.5mm cable.

Please check again.