Choosing right cable to power Power Supply Units

[multimarcus]

Hello everyone,
I need to supply power from an A/C wall plug to an enclosure containing 2 power supply units.
These are:
1 - Switching Power Supply INPUT 100-240v 3.0A / OUTPUT 5v = 40A --> connected to LED lights
2 - Power Supply Unit INPUT 100-240v 1.5A / OUTPUT 5v = 10A --> connected to microcontroller

I calculated that together they won't take more than 300Watts
The cable I will use is 3.5mts, it will have one UK plug on one end (with 13A fuse) and be connected to an electrical box.
And from there spliced to the 2 PSUs with WAGO terminal blocks.

Can I use one with the following specs:
Cross Sectional Area 1.50mm²
Material: VR Insulated / Though rubber sheath
3 cores
Voltage Rating: 300 / 500V

Thanks a lot for your time and for helping!!!
Marcus

 

[telectrix]

you could use 1.0mm cable fused in the plug at 13A, 5A

 

[westward10]

I get the input to around 1000w.

 

[telectrix]

I get the input to around 1000w.

that's max, assuming the load is as stated, probably be less.

 

[pc1966]

Can I use one with the following specs:
Cross Sectional Area 1.50mm²
Material: VR Insulated / Though rubber sheath
3 cores
Voltage Rating: 300 / 500V

Short answer is yes.

For the Wagos they take fine0stranded flex if they are the leaver sort, not the push-in ones.

Longer answers above is 1mm is probably acceptable, and the use of tough rubber or PVC (or even silicone rubber) are really down to the environment the cable goes through. The rubber cable like this sort is tolerant of oil and UV light so common for power leads out doors and in garages, etc:

H07RN-F FLEX MAINS & CONTROL CABLES EN60332-1-2

H07RN-F also known as EPR / PCP flexible mains and control cable is designed primarily as a trailing cable for use in the supply of energy for portable or mobile equipment. The cable can also be used in drainage, water treatment, cold environments and severe industrial environments and can...

www.superlecdirect.com

 

[multimarcus]

Short answer is yes.

For the Wagos they take fine0stranded flex if they are the leaver sort, not the push-in ones.

Longer answers above is 1mm is probably acceptable, and the use of tough rubber or PVC (or even silicone rubber) are really down to the environment the cable goes through. The rubber cable like this sort is tolerant of oil and UV light so common for power leads out doors and in garages, etc:

H07RN-F FLEX MAINS & CONTROL CABLES EN60332-1-2

H07RN-F also known as EPR / PCP flexible mains and control cable is designed primarily as a trailing cable for use in the supply of energy for portable or mobile equipment. The cable can also be used in drainage, water treatment, cold environments and severe industrial environments and can...

www.superlecdirect.com

Nice! Thank you! I was thinking of this one from CEF cable.
Yes the WAGOS are those with lever, rated at 32A.
Thanks for the explanation re rubber, I thought it was more resistant to heat, great to know about the environment. The installation is for indoor, I wanted to use rubber because of the way it bends (and smells ))

 

[multimarcus]

you could use 1.0mm cable fused in the plug at 13A, 5A

Thank you!
Yes, I did some calculations with the app on Doncastercables. It was giving me 1.0mm².
I thought 1.5 was going to keep me a little safer, just in case?

 

[multimarcus]

that's max, assuming the load is as stated, probably be less.

Thanks, yes, the load won't go beyond 300w (probably more approx 250w at max)

 

[pc1966]

Nice! Thank you! I was thinking of this one from CEF cable.

If you only need a few meters of cable then you might want to look at something like this:

Doncaster Cables 3 Core Round Flex Cable (3183Y)

• White.• BASEC• PVC insulated/sheathed• 300 - 500V• BSEN 50525-2-11

www.toolstation.com

However, if you have other plans for the rest of it, say to make up your own extension leads, etc, then going for a reel of 1.5mm rubber is a better bet. Or just buying it cut to length from the likes of Superlec.

 

[pc1966]

Thank you!
Yes, I did some calculations with the app on Doncastercables. It was giving me 1.0mm².
I thought 1.5 was going to keep me a little safer, just in case?

A short 1mm cable to a known fixed load is fine from a 13A fuse, as it will disconnect before the cable is damaged in the event of a fault.

More generally if the load is unknown, for example an extension lead, then 1.25mm is needed for 13A fuse (also uncoiled!) so it provides overload protection. But if the length is significant then 1.5mm is needed to keep voltage drop within reasonable limits (and is also more widely available).

You can also get 10A fuses for 13A plugs from the likes of RS components or CPC/Farnell (also 7A, 2A and 1A, as well as your common 3A/5A/13A), but they are unusual.

Thicker flex, like 2.5mm or above, won't fit sensibly in to the terminals of a 13A plug so really are not suitable for standard extension leads.

 

[telectrix]

or come to Tel's workshop/man cave. I got loads of short bits leftovers.

 

[Lucien Nunes]

0.75mm sq (rated 6A in free air) is perfectly sufficient, the PSU's cannot overload it, and it is sufficiently protected against short-circuit by a 13A fuse. It is the normal choice for electronic goods up to 1kW.

I think the '1000 W' mentioned above is a red herring. SMPSUs run at approximately constant efficiency so the input current is inversely proportional to the supply voltage. The maximum rated current is therefore quoted at the minimum rated voltage, 100V for both the above units. That makes the maximum total current with both PSUs fully loaded 3 + 1.5 = 4.5A at 100V or 450VA. At 230V the current will be 450/230 = 2A maximum, and less than if they are not pushed to their limits ( a microcontroller is not realistically going to take 100W, more like 2W)


It is pointless fitting a heavy cable rated for 15A to a system that will draw less than 2A, unless it is to be supplied from a non-RCD-protected source and you need to keep the loop impedance low.

 

[multimarcus]

or come to Tel's workshop/man cave. I got loads of short bits leftovers.

Thank you!!!

 

[multimarcus]

A short 1mm cable to a known fixed load is fine from a 13A fuse, as it will disconnect before the cable is damaged in the event of a fault.

More generally if the load is unknown, for example an extension lead, then 1.25mm is needed for 13A fuse (also uncoiled!) so it provides overload protection. But if the length is significant then 1.5mm is needed to keep voltage drop within reasonable limits (and is also more widely available).

You can also get 10A fuses for 13A plugs from the likes of RS components or CPC/Farnell (also 7A, 2A and 1A, as well as your common 3A/5A/13A), but they are unusual.

Thicker flex, like 2.5mm or above, won't fit sensibly in to the terminals of a 13A plug so really are not suitable for standard extension leads.

Great, thank you!

 

[multimarcus]

0.75mm sq (rated 6A in free air) is perfectly sufficient, the PSU's cannot overload it, and it is sufficiently protected against short-circuit by a 13A fuse. It is the normal choice for electronic goods up to 1kW.

I think the '1000 W' mentioned above is a red herring. SMPSUs run at approximately constant efficiency so the input current is inversely proportional to the supply voltage. The maximum rated current is therefore quoted at the minimum rated voltage, 100V for both the above units. That makes the maximum total current with both PSUs fully loaded 3 + 1.5 = 4.5A at 100V or 450VA. At 230V the current will be 450/230 = 2A maximum, and less than if they are not pushed to their limits ( a microcontroller is not realistically going to take 100W, more like 2W)


It is pointless fitting a heavy cable rated for 15A to a system that will draw less than 2A, unless it is to be supplied from a non-RCD-protected source and you need to keep the loop impedance low.

Thank you for the detailed explanation when it comes to electronics, really appreciated.
Does this mean that I could also go for a 1mm² a rubber wire like this?
It's rated for 300-500V, it will still be connected to a fused plug 13A.
Ah! Does this also work in Europe, if, let's say, I buy an EU adapter?

 

[Lucien Nunes]

Yes.

0.75 & 1.0mm sq. can be safely connected to EU power outlets when feeding a fixed load like this.

 

[multimarcus]

Yes.

0.75 & 1.0mm sq. can be safely connected to EU power outlets when feeding a fixed load like this.

Thanks heaps!