Switch/separate fused unit order question

[MM2005]

Hi
I have an electrical spur which currently powers my cooker hood and 3 under cabinet lights in my kitchen. The cooker hood and lights all go to a fused box on top of the cabinets (out of sight). The fused box is then connected to a fused switch (which in turn is connected to the power from the spur). I am busy re-doing the kitchen and wonder if it is necessary to have the fused switch as well as the fused unit above the cabinets? Would it be safe to have an unfused switch connecting the mains to the fused unit above the cabinets? Or should the fused unit come between the switch/mains connection?
I hope this is clear enough for you to understand. Thanks for your anticipated help!
Cheers
MM2005

 

[Steve]

I hope this is clear enough for you to understand. Thanks for your anticipated help!

could i be awfully rude and ask for clarification - what is this fused unit? can you take a picture and upload at image shack and post the link here.

 

[Big_Spark]

The lights and the Hood should be on seperate supplies, it sounds like the supply has been split and the lower spur controls the lights only.

It is likely that the supply to the first fused spur has been looped to the second fused spur and that the outputs of the respective spurs will only control either the Hood or the Lights.

Can you confirm that if one is off, the other equipment still works?

 

[MM2005]

Cheers for replies:

I've drawn out the connections (crudely):

http://img107.imageshack.us/my.php?image=switch6do.jpg

The FCU is just a standard fused terminal. Bear in mind that both connections from the FCU to the lights and from the (currently) fused switch to the FCU are behind tiles/wall units.

My original question was, do I need a fused switch (which I have currently) - or could this just be a normal switch (for 13 amp of course)? There is no way I can add a separate mains (that I can think of) without destroying the kitchen!

Your help is much appreciated.

CHeers
MM2005

 

[andy]

what you should have is 2 seperate feeds from the mains. 1 to power the cooker hood and 1 for the lights.

what you can do is take the cable from the first FCU on the ring main into 2 FCU's (instead of 1) and use 1 for the lights and 1 for the hood. have the first at 13A and the other 2 at 3A

i think this is what your asking?

 

[Big_Spark]

MM, try this for the connections.

It is how it should be done.



++++++++++++++++++++++++++++++++

what you should have is 2 seperate feeds from the mains. 1 to power the cooker hood and 1 for the lights.

what you can do is take the cable from the first FCU on the ring main into 2 FCU's (instead of 1) and use 1 for the lights and 1 for the hood. have the first at 13A and the other 2 at 3A

i think this is what your asking?

Adam, he can use a single supply, but they need top be seperated and independantly controlled locally, as per my drawing above.

 

[MM2005]

Thanks for your help Andrew. Yes, I guess so - my question was to do with how to do this safely given the predicament I have, i.e. the wires are already behind the walls!

Here's how I think you mean:

http://img261.imageshack.us/my.php?image=switch26fd.jpg

I have gone from the switch into the 13 amp FCU rather than having a splitter box (which I think you're suggesting). I think this will have the same result and be safe too?

If this is OK, my final question is do I need a fused switch where I have it on the diagram or can I get away with a standard switch (without fuse) as I have the fuses above? Or is it not wise to have an unfused switch directly from the mains (i.e. should there be a fuse before the switch if I was having an unfused switch)?

Sorry for the questions - I just think an unfused switch looks nicer. No harm if it's better/required to be fused.

Cheers
MM2005

 

[andy]

Adam, he can use a single supply, but they need top be seperated and independantly controlled locally, as per my drawing above.

im andrew

the way i suggested was to have 1 FCU feeding a further 2 FCU. that way, he has only 1 spur. i read it as the first FCU was on the ring main, and not the CU as your diagram

Thanks for your help Andrew. Yes, I guess so - my question was to do with how to do this safely given the predicament I have, i.e. the wires are already behind the walls!

Here's how I think you mean:

http://img261.imageshack.us/my.php?image=switch26fd.jpg

I have gone from the switch into the 13 amp FCU rather than having a splitter box (which I think you're suggesting). I think this will have the same result and be safe too?

If this is OK, my final question is do I need a fused switch where I have it on the diagram or can I get away with a standard switch (without fuse) as I have the fuses above? Or is it not wise to have an unfused switch directly from the mains (i.e. should there be a fuse before the switch if I was having an unfused switch)?

Sorry for the questions - I just think an unfused switch looks nicer. No harm if it's better/required to be fused.

Cheers
MM2005

all should be fused as mentioned in first post. in your diag, do you relize that the cable coming from the FCU going to the lights is not connected to the fused side of the hood FCU

 

[MM2005]

Cheers Andrew. So I should have one FCU going off into two separate ones. One (13amp) going to hood - One (3amp) going to lights.
I'm assuming I can replace the first FCU with a splitter box (but still have the 2 FCU's between hood/lights as said)?

Also, can you confirm whether fused switch is needed as on my diagram (i.e. the one at the bottom of the diagram)?

I could replace FCU between hood with fused switch I guess to try and isolate it as FSL suggests is required.

The problem with one switch of course means I can't turn the hood/lights on separately of each other, but not too bad I guess.

 

[andy]

Cheers Andrew. So I should have one FCU going off into two separate ones. One (13amp) going to hood - One (3amp) going to lights.
I'm assuming I can replace the first FCU with a splitter box (but still have the 2 FCU's between hood/lights as said)?

Also, can you confirm whether fused switch is needed as on my diagram (i.e. the one at the bottom of the diagram)?

I could replace FCU between hood with fused switch I guess to try and isolate it as FSL suggests is required.

The problem with one switch of course means I can't turn the hood/lights on separately of each other, but not too bad I guess.

from the first FCU (the 1 on the ring - 13A) take a feed to another 2 FCU's each of these FCU's will have a 3A fuse. 1 switch will work the cooker hood and the other will switch the lights

 

[MM2005]

Andrew, when you're saying switch in your last sentence I assume you mean FCU? The only switch I have (and can have unless I redesign my kitchen!) is the one labeled Fused Switch in my original diagrams.

Here is how I think it might work safely:

http://img305.imageshack.us/my.php?image=switch32oe.jpg

As you said except I have replaced the FCU to the hood with a switched fuse so it can be turned off independantly of the lights.

The 13amp fused switch is still the only way of turning both hood and lights on but I am not fussed about this. Is this safe?

I cannot do anything else as to getting two separate lines of supplied to hood and lights due to wiring already being done.

 

[Big_Spark]

Andrew, apologies for the Adam!! Don't know where that came from!!

MM, in your second diagram there is no need for the first FCU, however if you wish to keep it then so be it.

Other than that there is nothing wrong with diagram.

 

[Spark123]

Think this is what you are looking for, please note the two cables in the right hand side of the hood fcu are to be connected together in parallel to the load side.

 

[MM2005]

OK guys, thanks all for your help. I think the main thing here is having separate units (i.e. hood/lights in this case) on separate fuses (which it isn't at the moment). Don't worry they're not switch on anyway yet!

Should I have a switched FCU on the cooker hood or does it not really matter, seeing as I can turn this off at the 13amp fused switch?

 

[andy]

OK guys, thanks all for your help. I think the main thing here is having separate units (i.e. hood/lights in this case) on separate fuses (which it isn't at the moment). Don't worry they're not switch on anyway yet!

Should I have a switched FCU on the cooker hood or does it not really matter, seeing as I can turn this off at the 13amp fused switch?

do as suggested and then they can both be individually controlled via the FCU's. you need the first FCU feeding the other 2 otherwise it would be a spur on a spur. fair enough there isnt much load, but in the future someone else could add more load thinking its OK