Type of MCB .........................

[Toneyz]

In domestic when the Zs easily low enough why do we default to have type B instead of C curve MCB's/RCBO's

 

[westward10]

Mindset.

 

[Nigel]

Type B is designed for domestic use.

 

[Toneyz]

Type B is designed for domestic use.

I don't think designed more suitable for the load.

 

[davesparks]

Type B is designed for domestic use.

All 60898 mcbs are designed for use in domestic and similar premsis,not just type B

 

[Flanders]

Is it cost I always thought type C where more expensive than type B ?

 

[Nigel]

Ok. Not soley for domestic but you know what I mean.

There is little in a domestic that requires a Type C.

Installing MCBs that trip at 5-10 times the current rather than 2-3 times should not be installed unless required.

Having a few LED downlights will not require a Type C.

 

[Dave OCD]

Type B will respond better/quicker to an overcurrent so surely the better option when you don't have to allow for inductive loads or startup current for example.

 

[westward10]

In the days of predominate tungsten lighting I always fitted C 6A on lighting to prevent nuisance tripping from a failing lamp. B or C is mindset providing ADS is provided it is totally irrelevant.

 

[Nigel]

In the days of predominate tungsten lighting I always fitted C 6A on lighting to prevent nuisance tripping from a failing lamp. B or C is mindset providing ADS is provided it is totally irrelevant.

Choosing a B or C for me and the sparks I know is down to design.

 

[Dave OCD]

I used to fit C type for the old toroid type wound transformers feeding several halogen downlights with individual outputs, apart from that always B.

 

[Nigel]

My whole house is LED with the largest number on one switch six and all on a Type B.

 

[Deleted member 26818]

Type B will respond better/quicker to an overcurrent so surely the better option when you don't have to allow for inductive loads or startup current for example.

Both will trip in the same time if the current is enough to cause instantaneous operation.
It’s only the thermal side where a difference would be noted.

 

[westward10]

Ok. Not soley for domestic but you know what I mean.

There is little in a domestic that requires a Type C.

Installing MCBs that trip at 5-10 times the current rather than 2-3 times should not be installed unless required.

Having a few LED downlights will not require a Type C.

I don't actually know what you mean.

 

[Andy78]

I think a lot of it is down to availability too. We buy what the wholesalers have in for domestic stock. The wholesalers will be supplied with the devices that the manufacturers supply for domestic use.
This is generally a range of 6kA B curve breakers. You would have to specifically design for and request a C curve usually.

For instance Hager only do B curve mcbs in their 6kA range, and their reduced height RCBOs (aimed at consumer unit installation) at 6kA are all B curve.

 

[westward10]

There is no line of separation between a so called domestic protective device and a device for other purposes, it is mindset.

 

[bill01803]

Back along with wire wound transformers d type was the one to use unless to completely dropped the loading of the circuit.
Don’t you remember walking into a a room and hearing the transformer start!

 

[Andy78]

There is no line of separation between a so called domestic protective device and a device for other purposes, it is mindset.

Are the different product standards not a line of separation ?

 

[westward10]

Are the different product standards not a line of separation ?

The product standard is EN60898 or EN61009 it is the type characteristics which define the intent.

 

[Andy78]

The product standard is EN60898 or EN61009 it is the type characteristics which define the intent.

I was meaning the difference between 60898 and 60947-2, but I think I may be getting a little lost in the argument.
My point was that if a manufacturer's 60898 offerings are solely B curve, that could be a reason why it has become mindset to install them as default.