Computer Power Supply: is it SELV?

[dar07967]

Just a quick question: would a circuit run from a computer power supply (this type: http://www.amazon.co.uk/tag/atx power supply/products ) FELV, PELV, or SELV?

Thanks!

 

[Paul.M]

Depends on how the cables are run. Look at this

Extra-low voltage - Wikipedia, the free encyclopedia

 

[shanky887614]

personally I wouldn't because you would need to short pins out on the motherboard cable to start it unless you want 5v

 

[ian.settle1]

More like a switch mode power supply

 

[dar07967]

Hi there

I just tested one (a computer ATX power supply), and there is continuity between the ELV neutral and the LV earth.

So, that means it's not SELV. But can anyone help me deciding if it's PELV?

I am wondering whether these can be used to power 12VDC circuits according the regs (the power supply won't exceed 12VDC).

 

[Adam W]

What kind of 'circuits'? What do you actually want to do?

 

[dar07967]

Thanks for the reply.

The plan is to use a 12V power supply to power several items: (a) 12V PIR detectors; (b) waterproof LED strip lights; (c) CCTV cameras. No extra earth connections.

The complication is that they may be outdoors, but all connections will be made in IP55 boxes.

The alternative power supply is something like this: Buy LED Drivers LED Driver, 75W 24V 3.15A IP65 PowerLED PCV2475E online from RS for next day delivery. which is SELV.

So, the question really is - is a computer ATX power supply used for this type of circuit PELV?

Thanks for your help.

 

[shanky887614]

Thanks for the reply.

The plan is to use a 12V power supply to power several items: (a) 12V PIR detectors; (b) waterproof LED strip lights; (c) CCTV cameras. No extra earth connections.

The complication is that they may be outdoors, but all connections will be made in IP55 boxes.

The alternative power supply is something like this: Buy LED Drivers LED Driver, 75W 24V 3.15A IP65 PowerLED PCV2475E online from RS for next day delivery. which is SELV.

So, the question really is - is a computer ATX power supply used for this type of circuit PELV?

Thanks for your help.

whats the distance? the problem you will run into is a good quality 500 watt @12v psu will be around £40

get a bronze certificate psu for a cheap one that should be reasonably reliable

 

[dar07967]

whats the distance? the problem you will run into is a good quality 500 watt @12v psu will be around £40

get a bronze certificate psu for a cheap one that should be reasonably reliable

The voltage drop will be OK - will be using 2.5mm2 cable.

 

[shanky887614]

The voltage drop will be OK - will be using 2.5mm2 cable.

I was thinking more about the power draw and what will you do when power goes off and needs resetting?
it will need a lead making up to short two pins together to turn it back on

 

[dar07967]

I was thinking more about the power draw and what will you do when power goes off and needs resetting?
it will need a lead making up to short two pins together to turn it back on

Oh, OK. The power draw will be around 120W - the power supply will go up to around 300W/30A on the +12V rail.

(The power supply can be set to run automatically by permanently shorting the (green) PS_ON motherboard wire to a neutral wire, so no problems there.)