How many amps can a 6mm twin and earth cable take?
Owen Barnes
Published Apr 06, 2026
How many amps can a 6mm twin and earth cable take?
We plan to use our standard 1.5mm twin and earth cable that the manufacturer rates at 20 amps, but the cables are run under thick (more than 100mm) insulation in the loft (installation method 101) so our cables current carrying capacity is reduced to 13 amps (from top table)….How many amps 6mm cable can carry?
| Cable size | Rating in Amps |
|---|---|
| 6mm | 47 |
What current can 6mm twin and earth carry?
2 Answers from MyBuilder Electricians. 6mm twin and earth cable (which this almost certainly is) can be backed up by a maximum of a 32a MCB, even lower if other factors are involved. You’ll need that 10mm cable and a 40a MCB unfortunately as your shower is going to draw over 32a.
How many amps is 6mm cable good for?
Cable Size Chart
| Auto Size | Nom Area mm² | Amp Rating |
|---|---|---|
| 3mm | 1.13 | 20 |
| 4mm | 1.84 | 28 |
| 5mm | 2.90 | 37 |
| 6mm | 4.59 | 48 |
Can you have a 9.5 kw shower on 6mm cable?
9.5kW is either 39A or 41A depending on the voltage it is rated at. 6mm cable is 47A when installed in the most favourable conditions. So 6mm could be used, depending on how it is installed. However it would be usual to use 10mm which would allow the fitting of a higher rated shower either now or in the future.
What is the maximum load for 6mm cable?
The regulations allow for a 145% increase in current carrying capacity for one hour so using a 6mm for a maximmum load od 32A with a 32A MCB is acceptable. It is not possible to protect a 6mm cable with a maximum load of over 50A with a 32A MCB.
What size cable does a 9.5 kW shower need?
Cable Sizes by kW Rating
| kW Electric Shower Rating | Recommended Cable Size |
|---|---|
| 9500 (9.5 kW) | 10mm2 |
| 10,000 (10 kW) | 10mm2 |
| 10,500 (10.5 kW) | 16mm2 |
| 11,000 (11 kW) | 16mm2 |
What is 6mm cable used for?
6mm cable is normally used to power a cooker and or a hob. In older propertys you may find it has been run in to supplie a shower however 10mm is more appropriate now.
How many amps 6mm twin and earth cable can carry?
Simply so, how many amps can a 6mm twin and earth cable take? We plan to use our standard 1.5mm twin and earth cable that the manufacturer rates at 20 amps , but the cables are run under thick (more than 100mm) insulation in the loft (installation method 101) so our cables current carrying capacity is reduced to 13 amps (from top table).
Which is the maximum carring capacity for twin and Earth?
Looking at BS7671:2018 Table 4D5 which is specifically for 70 deg C Thermoplastic PVC cable (Twin & Earth) we have the maximum current carring capacities for various conductor sizes depending upon where they are installed and the amount of thermal insulation present, better know as ‘reference methods’.
What’s the maximum temperature for twin and earth cable?
In order to prevent this from happening we have a 70 Deg C maximum permitted temperature at the conductor for a standard thermoplastic PVC Twin and Earth cable. (See regulation 523.1 and Table 52.1 BS7671:2018) and we must ensure that our conductor does not go above this temperature.
How much current does a 6mm Cable carry?
The cables are still grouped. The spacing factors are not there for circuit design in terms of current carrying capacity. 6mm will carry 47amp clipped direct (on your tray, spaced from other cables). It will carry less than this in trunking, and even less if in trunking and grouped with other circuits.
Simply so, how many amps can a 6mm twin and earth cable take? We plan to use our standard 1.5mm twin and earth cable that the manufacturer rates at 20 amps , but the cables are run under thick (more than 100mm) insulation in the loft (installation method 101) so our cables current carrying capacity is reduced to 13 amps (from top table).
Looking at BS7671:2018 Table 4D5 which is specifically for 70 deg C Thermoplastic PVC cable (Twin & Earth) we have the maximum current carring capacities for various conductor sizes depending upon where they are installed and the amount of thermal insulation present, better know as ‘reference methods’.
Can a twin and earth be backed up with a 40A MCB?
In the tables for cables, I note that twin & earth, enclosed in conduit, installed in plaster, is only good for 39.4A. Am I correct in saying that the 6.00mm T&E should be backed up with a 32A mcb, as a 40A mcb, does not provide protection to the cable.
In order to prevent this from happening we have a 70 Deg C maximum permitted temperature at the conductor for a standard thermoplastic PVC Twin and Earth cable. (See regulation 523.1 and Table 52.1 BS7671:2018) and we must ensure that our conductor does not go above this temperature.
