two circuits on single RCBO?

[actionjackson]

I would appreciate some guidance for installing UFH and a whirlpool bath in my bathroom on a 16A rcbo currently unused in my CU.

UFH is rated @ 5 amps
Whirlpool bath @ 4 amps

Can i install two seperate loads on a single RCBO?

The UFH is controlled/switched by an electronic programmer. I plan to install a switched double pole FCU for the whirlpool.

Question is, does the UFH also require a FCU for downrating?

 

[ericmark]

Can i install two seperate loads on a single RCBO?

I will depend if you want to pay the LABC their silly fees? Because of Part P to DIY has become more expensive than to use a registered electrician. But two items can be feed from same circuit

The UFH is controlled/switched by an electronic programmer. I plan to install a switched double pole FCU for the whirlpool.

Question is, does the UFH also require a FCU for downrating?

This is down to manufacturers recommendations. For fixed appliances they can stipulate max and min values. Also the separation values and ability to lock off may mean the thermostat is unsuitable as an isolator. I would fit a FCU or a Plug to every item after the RCD/RCBO so if there is a fault I can isolate both live supplies (Line and Neutral).

Do remember not all under floor heating can be used in a bathroom do ensure you get right type. I had to write to manufacturers to find out which could be used when I fitted it. Lucky the person was disabled so no LABC charge.

 

[actionjackson]

Can i install two seperate loads on a single RCBO?

I will depend if you want to pay the LABC their silly fees? Because of Part P to DIY has become more expensive than to use a registered electrician. But two items can be feed from same circuit

The UFH is controlled/switched by an electronic programmer. I plan to install a switched double pole FCU for the whirlpool.

Question is, does the UFH also require a FCU for downrating?

This is down to manufacturers recommendations. For fixed appliances they can stipulate max and min values. Also the separation values and ability to lock off may mean the thermostat is unsuitable as an isolator. I would fit a FCU or a Plug to every item after the RCD/RCBO so if there is a fault I can isolate both live supplies (Line and Neutral).

Do remember not all under floor heating can be used in a bathroom do ensure you get right type. I had to write to manufacturers to find out which could be used when I fitted it. Lucky the person was disabled so no LABC charge.

Thanks for the advice.

The UFH is Warmup and is suitable for bathroom instalations. I will contact warmup and ask if a FCU is needed for isolation. The UFH load is 5 amps so wouldn't it be compolsoary to downrate the supply to 13 amps?

I'm aware of the Part P regs but haven't decided if i will get a registered electrician in or carry out the works myself after notification to the LBAC. I'm qualified in electrical electronic engineering (10 years ago) and have passed 16th edition so have the ability to carry out the works safely but need guidance because i have been off the tools for 5 years and my background is military/offshore...

 

[ericmark]

With my local LABC charging £100 + Vat last time I asked for all work up to £2000 small jobs are just not economic to DIY.

As to fusing down that depends on manufacturers recommendations so I can't answer. Personally I would use switched FCU's allowing isolation and lock off in case of a fault.

 

[actionjackson]

With my local LABC charging £100 + Vat last time I asked for all work up to £2000 small jobs are just not economic to DIY.

As to fusing down that depends on manufacturers recommendations so I can't answer. Personally I would use switched FCU's allowing isolation and lock off in case of a fault.

Just spoke to Warmup customer services which was a waste of time. They can't advise if a 16 amp RCBO needs fusing down for the 5.2 Amp UFH. Apparantly its up to the electrician to decide?

 

[riveralt]

With my local LABC charging £100 + Vat last time I asked for all work up to £2000 small jobs are just not economic to DIY.

As to fusing down that depends on manufacturers recommendations so I can't answer. Personally I would use switched FCU's allowing isolation and lock off in case of a fault.

Just spoke to Warmup customer services which was a waste of time. They can't advise if a 16 amp RCBO needs fusing down for the 5.2 Amp UFH. Apparantly its up to the electrician to decide?

For goodness sake - the purpose of the MCB side of the RCBO is to protect the cable not to protect the equipment. What size cable are you using? Clipped direct 1.5mm - Conduit 2.5mm - though you might get away with 1.5mm.
If the manufacturers instructions don't instruct then stick with 5Amp FCU's for both.

Since you intend to stick two circuits on one RCBO then you need to be able to isolate one without affecting the other.

 

[ban-all-sheds]

Apparantly its up to the electrician to decide?

Well - you want to be the electrician in this case, so you are the one to decide.

 

[ericmark]

Apparantly its up to the electrician to decide?

Well - you want to be the electrician in this case, so you are the one to decide.

Well put. One can't DIY without having the knowledge required. The point is portable appliances like your TV can't rely on the fuse in the plug or supply MCB's and if the manufacturer decides it needs a 2A fuse he must include it in the TV.
But once we move to fixed appliances then the manufacturer can and in many cases does stipulate what protection is required. He can stipulate semi-conductor fuses, MCB's, motor overloads and the installer has to provide them. And the commissioning engineer will check they are in place.
If you want to DIY then that will include filling in an insulation certificate where you sign for the design, installation, and inspection and testing. You can employ someone to do one or more of those functions but you can't write in design "As advised on a forum" you must have some one to visit and sign the form. The completed form you will give to LABC who if they don't believe what is written down can re-test any items. So they don't do testing for you they verify your results. Some LABC will test for you at an extra charge.
If you were doing a full house re-wire then to buy or hire test equipment may be worth while. But in real terms the option to DIY and involve the LABC is not really for Joe Public but for people like me who have a full test set know exactly what they are doing but are not a member of a scheme.
Putting it bluntly the job is too small to be worth doing as a DIY.

 

[riveralt]

Apparantly its up to the electrician to decide?

Well - you want to be the electrician in this case, so you are the one to decide.

Well put. One can't DIY without having the knowledge required. The point is portable appliances like your TV can't rely on the fuse in the plug or supply MCB's and if the manufacturer decides it needs a 2A fuse he must include it in the TV.
But once we move to fixed appliances then the manufacturer can and in many cases does stipulate what protection is required. He can stipulate semi-conductor fuses, MCB's, motor overloads and the installer has to provide them. And the commissioning engineer will check they are in place.
If you want to DIY then that will include filling in an insulation certificate??? where you sign for the design, installation, and inspection and testing. You can employ someone to do one or more of those functions but you can't write in design "As advised on a forum" you must have some one to visit and sign the form. The completed form you will give to LABC who if they don't believe what is written down can re-test any items. So they don't do testing for you they verify your results. Some LABC will test for you at an extra charge.
If you were doing a full house re-wire then to buy or hire test equipment may be worth while. But in real terms the option to DIY and involve the LABC is not really for Joe Public but for people like me who have a full test set know exactly what they are doing but are not a member of a scheme.
Putting it bluntly the job is too small to be worth doing as a DIY.

Crossed wires????