Limited to 7.5kw shower?

GDB2222

I’ve missed the point that the effective length is doubled. Is the table really for a single conductor, not for T+E? The online calculator is for T+E, if I recall correctly.

coffeehound

GDB2222 said:

I’ve missed the point that the effective length is doubled. Is the table really for a single conductor, not for T+E? The online calculator is for T+E, if I recall correctly.

Yes the tables are for T+E.  I had to double it as using the basic R for 6 sq mm copper

danrv

Section62 said:

coffeehound said:

From danrv's question, it does look marginal to run even 7.5 kW shower from 6 sq mm when under insulation.  Think in that situation I'd rather do the plumbing to run the mixer shower from the E10-heated tank.

Same here - if you've got hot water heated at cheap rate then it makes sense to use that, rather than pay to heat water at the rate when you use it.

The current E10 rates might have marginal benefit compared to a really good single tariff, but I wouldn't expect that to last as we all get 'encouraged' to move to TOU charging via our smart meters.

Does make sense yes, having now looked a power showers available.
The old bidet feed from the loft tank could have been used. At the time, I couldn’t think of a reason to keep it so took it back and capped it at the tank.
I suppose a bathroom company may have suggested a tank fed power shower but electric 
was installed before so went with that as supply’s in place already.