Single phase supply--> 2 electric showers

[making_1998]

I recently installed a 2nd electric shower in my in laws house. There are now two 8.5kw showers installed. The supply fuse is rated at 60amps. Both showers running together would draw ~70amps.
To over come this, I installed a 40A 30ma RCD with a 40amp MCB. The output from the MCB I have connected to a 40amp DP contactor. The switch for this contactor is fed from a lighting circuit and consists of a 5amp pull cord switch beside shower #1. Depending on the wheter this switch is on or not, power will either go directly to shower #1 or to a DP 40amp pull cord switch to supply shower #2.
With this set up only one shower can be on at once and shower#1 has to be switched off before shower#2 can operate. This is a small in convenience, but I was wondering if it was okay to leave installation like this. Is it okay to use just one 40amp MCB ?

 

[plugwash]

sounds generally ok just a couple of things to mention

1: i would have used 2 way switching on the contactor control cuircuit
2: you shouldn't be relying on the contactor as the local isolation for shower 1 both showers should have double pole isolating swiches either as pullcords in the bathroom or wall mounted near the bathroom

 

[ban-all-sheds]

All I can say is that it's a good job FWL isn't here...