What Size Electric Shower Can I Replace My Existing Electric Shower With?
We are called quite often from property owners saying that their existing shower is not working right any longer and they just want’s it swapping out.
In this video we explain exactly what to look for and how to determine the answer.
Number 1: The existing size of the MCB in the consumer unit (electric box, distribution board or whatever others may call it)
Number 2: The size of the cable from the consumer unit to the shower isolator and isolator to shower. Never assume it’s the same!
Number 3: The route the cable takes, does the cable go up the wall (behind the plaster) and then in the loft, under the insulation and to the isolator? For instance
Number 4: The existing showers output (this sometimes opens up a can of worms as the existing shower may be too powerful)
So, after gathering the above information I then have to make a few calculations
Take the wattage of the desired shower and divide by the voltage
For instance, the property owner would really like a 9.5KW electric shower so I covert the 9.5kw to watts, there are 1000watts per kw, so 9.5 x 1000 = 9,500 watts
The voltage we use for calculation purposes in residential properties is 230v
Therefore, we take 9,500(w) and divide this by 230(v). The answer will give us the amperage that the miniature circuit breaker (MCB) needs to be, this calculation gives us 41.3 amps. I round this down to a 40amp breaker.
Do they have a 40a MCB in their consumer unit that fed the old shower.
Can you obtain a 40a MCB that is the same MCB for that consumer unit. Older consumer units maybe not.
Assuming we have Yes answered to either Step 1 or Step 2, we now need to determine whether the cable they have that runs from the consumer unit to the shower, can carry 40 amps.
Please refer to the following website, as we show you in the video: