Electrisaver Boost installation together with heater switch

[andreasy]

Hello everyone,

I have a 30Amp heater switch that controls my hot water immersive heater and I have bought a horstmann boost control (Horstmann :: Electrisaver) which is 13Amp and I need to install this together with the heater switch in order to automatically control the time my heater switch operates.

My question is:
Both the heater switch and boost have Mains (L/N) and Load (L/N). The way I'm considering to install is to connect the mains supply on the boost and from boost out to send to heater switch mains and heater switch load to immersive heater. assuming that it is a 30Amp HS, is this correct or should I install mains supply on heater switch, heater switch load to boost mains and boost load on immersive heater?

I hope I explained well.

 

[Sintra]

First thing to check is that the current rating of the immersion is less than or equal to 13A.

 

[andreasy]

I have no way to check that now but as far as I can remember, it should be higher than 13A, hence the 30A HS

 

[Sintra]

So if your load is greater than 13A why the heck are you thinking that a 13A electrisaver would be a suitable replacement for your existing 30A switch.

 

[Engineer54]

The largest immersion element i have seen on a domestic installation in Cyprus is a single 4.6 KW jobbie and that was a pretty big water tank. I take it, that this is on a roof solar water heating system with an electrical back-up element for early morning winter use, or the extremely rare days where there isn't any or much sun!!

Anyway, regardless of what the switch rating is (and it's generally a 20A switch not 30A), the vast majority of all these solar system immersion heaters will be 3 KW, and use a typical UK immersion heater element and thermostat.

The Holstman timer should fit directly into the single 25/35mm back box (you may need a spacer for a 25mm depth box with the Holstman unit) that the existing immersion switch is currently occupying. Your means of local isolation would then be the circuits 16A MCB in the DB/CU, that is probably a couple of metres away at most, on the same upstairs landing!!

Yes i do know about Cyprus, that is my permanent place of residence... lol!!