guys a quick ask please,during re-fitting a bathroom i've been asked to change the old immersion heater(no longer works),noticing that at some point the wiring has been hijacked to power the shower pump...i can run some new cable direct from the box and install a new outlet no problem-is this 2.5t+e as existing supply?,16Amcb?-advice needed please.
immersion heater wiring
- Thread starter bigbrother3269
- Start date
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I assume you are getting the immersion system back up and running?
If the rating of the protective device is 16A and the load on demand is less than that, the cable of choice would be one that can safely carry 16A.
Don't be fooled by the section of cable, when manufactures state a value the cable can carry, as this is a maximum value and certain factors, such as route the cable is taking, the method of installation (clipped direct, within walls/ceilings, trunking/conduit) and if any thermal insulation is within the route of the cable and also the distance the cable run needs to be given for voltage drop. These all need to be calculated in before a safe selection can be made.
If cable is routed through thermal insulation, it can have a de-rating factor of up to 50%.
2.5mm T&E can carry a maximum current of 27A but as soon as it is installed within thermal insulation for a distance equal or greater than 500mm, that can then drop to 13.5A.
So a little more information is required.
If the rating of the protective device is 16A and the load on demand is less than that, the cable of choice would be one that can safely carry 16A.
Don't be fooled by the section of cable, when manufactures state a value the cable can carry, as this is a maximum value and certain factors, such as route the cable is taking, the method of installation (clipped direct, within walls/ceilings, trunking/conduit) and if any thermal insulation is within the route of the cable and also the distance the cable run needs to be given for voltage drop. These all need to be calculated in before a safe selection can be made.
If cable is routed through thermal insulation, it can have a de-rating factor of up to 50%.
2.5mm T&E can carry a maximum current of 27A but as soon as it is installed within thermal insulation for a distance equal or greater than 500mm, that can then drop to 13.5A.
So a little more information is required.
If the immersion is used (more or less never) as a back up for hw should the boiler fail then a 3 amp spur for a pump via a fuse spur unit will be ok.
As mentioned a 2.5mm the in clean air copes with circa 26 amp, if the route for tha cable isnt surrounded by insulation you will be fine.
As mentioned a 2.5mm the in clean air copes with circa 26 amp, if the route for tha cable isnt surrounded by insulation you will be fine.
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