Confused about how to do this

[Dylan123]

Hi,

I am getting a media wall installed. I want to light it internally with 180 watts of flexible tube.

This runs off 24V so in my mind

180W
——- = 7.5A
24V

There is existing lights in the space so I wanted to power from here, this is above a 5A fuse on the circuit. Also, the kit is mains plug.

Is the amp calc correct? Low voltage lighting uses a high ampage?

2nd question.

I have one spur to power: 2 KW fire, TV and other appliances like PlayStation. And the lights. A bit worried one spur can’t handle that.

the floor is laminate so don’t want to get it up. If the spur isn’t right, I can bring another spur down from upstairs.

I am wondering also, adding all this to the downstairs main will be too much for 30A when washing machine/airer etc is running.

Do fires usually go off their own circuit to the board?

Over to you!

Thanks

 

[AdrianUK]

Nope. You have gotten a little confused with the calculations.

You are right that 180W @ 24V is 7.5A BUT ... it is the power which is the constant..... so 180W @ 230V = 0.78A (ignoring losses & assuming your 230V to 24V converting widget is 100% efficient.... which it wont be.... but 0.8A will be close enough)

7.5A @ 230V would be 1,725W

(And before anyone chips in ..... I know 7.5A @ 230V AC would technically be 1725VA not 1725W but lets not worry about power factor for the moment!)

 

[Jurassicspark]

Hi,

I am getting a media wall installed. I want to light it internally with 180 watts of flexible tube.

Ok. 180W sounds a lot.

This runs off 24V so in my mind

180W
——- = 7.5A
24V

There is existing lights in the space so I wanted to power from here, this is above a 5A fuse on the circuit. Also, the kit is mains plug.

Is the amp calc correct? Low voltage lighting uses a high ampage?

How many amps can the power supply output?

2nd question.

I have one spur to power: 2 KW fire, TV and other appliances like PlayStation. And the lights. A bit worried one spur can’t handle that.

Ditch the electric fire to somewhere else and it will be able to handle it.

If the spur isn’t right, I can bring another spur down from upstairs.

You can do that but the socket from where you will spur from should not be already supplying another spur (if its a ring circuit)

I am wondering also, adding all this to the downstairs main will be too much for 30A when washing machine/airer etc is running.

Do fires usually go off their own circuit to the board?

It will be okay. Even on an underload condition, the MCB will trip and prevent from any fires.

 

[Dylan123]

Ok. 180W sounds a lot.

How many amps can the power supply output?

The media wall is a central bit with the tv and either side there are alcoves. Currently there is a lamp in each alcove from the lighting circuit for the downstairs.

I want to fill each alcove with built in shelves aboht 16 - 20 inches between shelves so there will be about 5-6 shelves.

These lamps will have to go as they will be in the shelving.

I was hoping to use th to power the RGB flexible lighting which will be recessed into the bottom of each shelf.

The issue is the kit is mains so it makes more sense to just cover these over and run the lights from the power inside the media wall.

It just seemed logical to use that power for the lights but it’s impractical as I have the transformer to think about so would have to chase it back from the alcove anyway into the main central unit - far easier to just make sure there’s enough mains power in the middle.

I think the best COA is:

- Ignore the lights in the alcove, plate them off and clad, the back of the alcoves with be clad anyway.

- accept the 1 spur in the middle won’t power it all.

- Bring down a spur from the upstairs to power the fire alone. Mark on CU. Seems best to put the heavy using item off the upstairs which gets used rarely.

- Use the existing spur to power the TV, lights and sky etc.

Make sense?

Another question.

I need another socket downstairs. Given the floor. Taking 2 spurs from upstairs makes sense down the wall (house is being decorated too)

I know you can’t spur a spur, but do regs allow 2 spurs from the same RM? Ie a spur from 2 sockets on the same main?

 

[Jurassicspark]

- Bring down a spur from the upstairs to power the fire alone. Mark on CU. Seems best to put the heavy using item off the upstairs which gets used rarely.

- Use the existing spur to power the TV, lights and sky etc.

Ok.

Make sense?

Another question.

I need another socket downstairs. Given the floor. Taking 2 spurs from upstairs makes sense down the wall (house is being decorated too)

I know you can’t spur a spur, but do regs allow 2 spurs from the same RM? Ie a spur from 2 sockets on the same main?

Yes.

 

[ericmark]

A 180 watt power supply will likely have a range of in coming voltage, say 100–240 volts, and it will likely be switched mode, so it had a capacitor to charge, so in-rush could easily be 2 amps, even if running amps only 0.78.

My cabinet lights are around the 60 watt mark, at full output, but rarely set to even half.

To me, 180 watt seem rather OTT.

 

[AdrianUK]

A 180 watt power supply will likely have a range of in coming voltage, say 100–240 volts, and it will likely be switched mode, so it had a capacitor to charge, so in-rush could easily be 2 amps, even if running amps only 0.78.

My cabinet lights are around the 60 watt mark, at full output, but rarely set to even half.

To me, 180 watt seem rather OTT.

A ~200W SMPSU, the initial in-rush to fill that capacitor would be alot more than 2A. I wouldn't be surprised to find its in the order 50A for a few mS.

 

[SFK]

CPC is Good supplier of electrical supplies in my opinion.
Here are their 24V DC led power supplies

https://cpc.farnell.com/c/electrical-lighting/batteries-power-supplies/power-supplies/led-power-supplies/led-power-supply-24v

And I had a very quick look and this should be suitable for your 24Vdc constant voltage, 180W requirements.

https://cpc.farnell.com/tiger-power-supplies/tgr-24v-200w/led-driver-24v-200w-waterproof/dp/PW04908?st=led%20power%20supply%2024v