I have a 2.5 cable from con unit approx 15 Mtr through joist no insulation to a fused spur under sink. Can I connect a 3.7kw ins water heater to this ? Thanks
instantaneous water heater
- Thread starter chucka
- Start date
Is the cable a direct circuit, as in it has its own fuse at the board end?
What fuse rating is at the board end?
Does the cable serve anything else along the way? What was the fuse spur use for previously?
2.5mm direct feed radial circuit will take 20 amp. 20 amp x 230v gives a capacity of 4.6kw. Well over your requirement, subject to it not being spurred along the way, or being a spur from a circuit with other loads on it.
What fuse rating is at the board end?
Does the cable serve anything else along the way? What was the fuse spur use for previously?
2.5mm direct feed radial circuit will take 20 amp. 20 amp x 230v gives a capacity of 4.6kw. Well over your requirement, subject to it not being spurred along the way, or being a spur from a circuit with other loads on it.
You can but you must not. The fused spur unit can take a max 13 amp fuse. 3.7 kW is more than 13 amp.
The cable is a single cable direct from con unit. I know it should have been 4 mm but made a mistake when rewiring house. I did first fix, electrician 2nd, told him what it would be used for but he never told me to use 4mm
It is a 16 at mo but will put in whatever is necessary
20A switch with a flex outlet for the heater, existing cable and 16A MCB left as they are.
That's is not how it is done! The MCB is selected dependant on the cable size, and the installation conditions.
HOWEVER
16 amps at 230 volts is nearly 3.7KW, so you could connect that heater up. Just change the FCU under the sink to a 20amp DP switch without making any other changes.
Thanks everyone. will check with my electrician before buying unit.
DIYnot Local
Staff member
If you need to find a tradesperson to get your job done, please try our local search below, or if you are doing it yourself you can find suppliers local to you.
Select the supplier or trade you require, enter your location to begin your search.
Are you a trade or supplier? You can create your listing free at DIYnot Local
