Ls Lr why isn’t some dont bother

[cliffed]

Just your thoughts on this one,helping a sparky out on a real nice ufh system wireless stats & heatmiser wireless control box.
i asked you got all the cables in from boiler to junction boxes.,3core to each one mate.
why is it they don’t look @the diagram,it shows a volt free contact,to the boiler & each box.
Ls Lr.
We will use the signal cable only,you don’t need the other one,it will go on the Lr & get the live off the local junction box.
it’s not what the drawing says,& also what if that volt free contact isn’t @ 230v.
I do believe it’s still workable but,drawings are there & should be adhered too O,its lucky there are the valve switches & the stats too,for the switchable option.

 

[Leesparkykent]

The volt free contact on heatmiser wiring centres is fine for 230V.

 

[davesparks]

Not quite sure I follow the post completely but yes drawings should be followed, they will have been drawn the way they are for a reason.

The use of Ls and Lr terminals at a boiler is usually done so that if the internal fuse in the boiler were to operate it makes the whole thing dead. If a permanent live is picked up from elsewhere to feed to the Lr terminal then it bypasses the boilers internal fuse and the Lr can remain live when the internal fuse operates.
[automerge]1590923581[/automerge]

The volt free contact on heatmiser wiring centres is fine for 230V.

I think the OP is referring to the boiler's Ls and Lr terminals not always being 240V.

As far as I can make out the problem is that the other person is planning to use a permanent live to one side of the volt free terminals in the heatmiser then just take a S/L to the Lr terminal of the boiler.
The way it should be done is, obviously, the Ls and Lr of the boiler connected across the volt free terminals of the heatmiser.

 

[cliffed]

Cheers it bothers me why this is not adhered too.
They have wireless stats too,but switching, does not alter the enable function @ the heatmiser

 

[freddo]

If a permanent live is picked up from elsewhere to feed to the Lr terminal then it bypasses the boilers internal fuse and the Lr can remain live when the internal fuse operates.

It will also bypass the mains switch on the boiler.

 

[cliffed]

It will also bypass the mains switch on the boiler.

Good point,like we all said the volt free needs to be connected,in the way it should be.

 

[davesparks]

It will also bypass the mains switch on the boiler.

If it has one yes, they don't all have an on/off switch on them.