Cable Route

[wreck-it-steve]

Hi,

I know that mains cables have to be within safe zones etc but is there any requirements for 12 / 24v cables?

I need to get a cable to power a 12 or 24v light and there is no ideal cable route.

Thanks

 

[PrenticeBoyofDerry]

//www.diynot.com/wiki/Electrics:walls
Requirement 522.6.101 goes on to say:
A cable concealed in a wall must be:
i. be at least 50mm from surface, or
ii. have earthed armouring or an earthed metal sheath, or
iii. be enclosed in earthed steel conduit or trunking, or
iv. be provided with mechanical protection sufficient to prevent penetration of the cable by nail, screw and the like, or
v. be installed either horizontally within 150mm of top of the wall, or partition or vertically within 150mm of the angle formed by two walls, or run horizontally or vertically to an accessory or CU, or

vi. form part of a SELV or PELV circuit.

 

[wreck-it-steve]

//www.diynot.com/wiki/Electrics%3Awalls
Requirement 522.6.101 goes on to say:
A cable concealed in a wall must be:
i. be at least 50mm from surface, or
ii. have earthed armouring or an earthed metal sheath, or
iii. be enclosed in earthed steel conduit or trunking, or
iv. be provided with mechanical protection sufficient to prevent penetration of the cable by nail, screw and the like, or
v. be installed either horizontally within 150mm of top of the wall, or partition or vertically within 150mm of the angle formed by two walls, or run horizontally or vertically to an accessory or CU, or

vi. form part of a SELV or PELV circuit.

Even for 12v DC fed from a transformer?

 

[JohnW2]

//www.diynot.com/wiki/Electrics%3Awalls
Requirement 522.6.101 goes on to say:
A cable concealed in a wall must be:
i. be at least 50mm from surface, or
ii. have earthed armouring or an earthed metal sheath, or
iii. be enclosed in earthed steel conduit or trunking, or
iv. be provided with mechanical protection sufficient to prevent penetration of the cable by nail, screw and the like, or
v. be installed either horizontally within 150mm of top of the wall, or partition or vertically within 150mm of the angle formed by two walls, or run horizontally or vertically to an accessory or CU, or
vi. form part of a SELV or PELV circuit.

Even for 12v DC fed from a transformer?

I'm not sure what question you're asking. Given all the "OR"s between those points, if it's 12V (or 24V), hence "SELV or PELV", then (vi) is satisfied, so none of (i) to (v) have to be satisfied.

Kind Regards, John

 

[bernardgreen]

is there any requirements for 12 / 24v cables?

As has been said there are no regulations as such but common sense shoud be used.

Consider what will happen if the cable is damaged and then risk analyse the hazards if any created by that damage.

Most ELV circuits in domestic use present no hazard ( other than callers are missed because the door bell wire has been cut )

How powerful is the lamp, what is feeding the cable and has that source got protection against over load ?. I have seen charred ELV transformers that would have survived had there been a fuse in their output

 

[PrenticeBoyofDerry]

Even for 12v DC fed from a transformer?

If the cable feeding the 12V transformers is that of domestic low voltage (normally at 230V/240V) then that must comply to one of the given requirements from i-v of 522.6.101.
It would only be the load cables for the secondary side of the transformer that would be applicable to requirement vi.

 

[JohnW2]

If the cable feeding the 12V transformers is that of domestic low voltage (normally at 230V/240V) then that must comply to one of the given requirements from i-v of 522.6.101. It would only be the load cables for the secondary side of the transformer that would be applicable to requirement vi.

That's clearly all true, but is it not "load cables for the secondary side of the transformer" that the OP (who already knows that LV cables must be in safe zones) is asking about?

I know that mains cables have to be within safe zones etc but is there any requirements for 12 / 24v cables?

Kind Regards, John