Range Cooker Connection Refusal.

wallywombat: 
The point I was trying to make is that every appliance, by the nature of its design, will have a range of CB ratings that it can comfortably and safely work with. If the manufacturer tells us this info, it gives us maximum flexibility. For example, if an appliance is specified as needing a 32-50A CB, then we can wire it to an existing 40A circuit without changes. If the manufacturer just says “must use a 25A breaker” then the circuit has to be modified, or an an extra circuit added, before the appliance can be added. Which is annoying, as one might suspect that it would actually be ok with a 40A breaker too, if only the manufacturer would tell us!

Agreed … some manufacturers could be a little more open about this. Having said that, some manufacturers have bad experiences of horror installations, and having to prove it's not their appliance that caused the fire … it works both ways.

There are also cultural issues here. For example, installers in some countries feel the manufacturer should specify the OCPD, whereas I get the impression certainly many competent electricians in the UK feel they are being undermined, or, as you say, restricted, by the manufacturer being so specific … especially when it's printed alongside other installation instructions that are clearly nonsense or not applicable in the UK !

wallywombat: 
The point I was trying to make is that every appliance, by the nature of its design, will have a range of CB ratings that it can comfortably and safely work with. If the manufacturer tells us this info, it gives us maximum flexibility. For example, if an appliance is specified as needing a 32-50A CB, then we can wire it to an existing 40A circuit without changes. If the manufacturer just says “must use a 25A breaker” then the circuit has to be modified, or an an extra circuit added, before the appliance can be added. Which is annoying, as one might suspect that it would actually be ok with a 40A breaker too, if only the manufacturer would tell us!

Agreed … some manufacturers could be a little more open about this. Having said that, some manufacturers have bad experiences of horror installations, and having to prove it's not their appliance that caused the fire … it works both ways.

There are also cultural issues here. For example, installers in some countries feel the manufacturer should specify the OCPD, whereas I get the impression certainly many competent electricians in the UK feel they are being undermined, or, as you say, restricted, by the manufacturer being so specific … especially when it's printed alongside other installation instructions that are clearly nonsense or not applicable in the UK !