Sunny Boy 4000TL Multi Function Relay

[Orty]

View attachment img116.pdf
I am about to replace my 3Kw Immersion Heater with a 1.5Kw. Please see the attached PDF
I intend to control it with the multi function relay in the Sunny Boy turning on at 1800w. The default setting for self consumption is 1500w
The other settings I am considering altering are the default 30mins for start up power to 15mins.
The original IH timeswitch will be left in circuit for manual/timed operation and the Sunny Boy will overide this.
Has anybody any comments to make on my proposed system please.

Thanks

Orty

 

[Gavin A]

presumably you know you need a contactor as well, and can't run the immersion heater direct from the relay?

 

[BruceB]

I spy a contactor in his diagram.

The circuit is fine in principle, in that it would work. What you could do is think through where you have isolation/fusing/mcb. It is always tricky when you have something that can be powered from x2 routes, but you do not want the second route energising unexpectedly whilst someone is working on it.

Personally I would keep the 'control' aspects and 'power' aspects separate. So:
- single mcb runs the whole lot
- fused spur for the control elements of sunny boy and timer
- timer powers the contactor coil rather than the immersion direct
- if the connection to the sunny boy cannot be safely unplugged at the sunny boy to isolate, then put in an isolator.

Regards
Bruce

 

[Orty]

Both circuits would be from the same trip in the consumer unit, so effectivley all can be isolated in one action.

 

[Gavin A]

I spy a contactor in his diagram.

tbf when I wrote that I'd not spotted there was a diagram...