Rules and Guidelines
Want to participate in the discussions? Please read our Community Rules and Guidelines. Need some help? Visit Support and Answers.

  • State Not Answered
  • Locked Locked
  • Replies 32 replies
  • Subscribers 32 subscribers
  • Views 2802 views
  • Users 0 members are here
Options
You may also be interested in
This discussion is locked.
You cannot post a reply to this discussion. If you have a question start a new discussion

Range Cooker Connection Refusal.

Zoomup

A lady today asked me to estimate to do some cooker circuit alterations in her house. She has an old electric range cooker in the kitchen which she is to replace with a new one rated at about 11.2kW.

 

A certain national electrical retailer would not connect up her new and paid for range cooker as the cooker supply is run in 10.00mm2 T&E and protected by a B50 M.C.B. plus R.C.D.

 

The reason given was that the supply is too big and will overload the new cooker.

 

The retailer insisted that the  B50 M.C.B. be replaced by a B40 M.C.B. and the final cooker connection from connection unit to cooker, be run in 6.0mm2, the 10.002 final connection being removed.

 

Comments please.

 

Z.

 

 

 

 

Parents
  • 0

    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!

    I think that we can all see why a minimum size of MCB should be specified, but I am struggling to see why the maximum should be for a dedicated one appliance circuit. If the cooker specifies, say 40 A and 6 sqmm cable, but 50 A and 10 sqmm are used, the circuit cannot be overloaded. You could even use 6 sqmm cable on the 50 A MCB subject to the higher let-through energy of the larger MCB not being excessive - 433.3.1(ii).

Reply
  • 0

    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!

    I think that we can all see why a minimum size of MCB should be specified, but I am struggling to see why the maximum should be for a dedicated one appliance circuit. If the cooker specifies, say 40 A and 6 sqmm cable, but 50 A and 10 sqmm are used, the circuit cannot be overloaded. You could even use 6 sqmm cable on the 50 A MCB subject to the higher let-through energy of the larger MCB not being excessive - 433.3.1(ii).

Children
No Data

Join us to get the best from IET EngX.

Joining EngX lets you personalise your experience so you stay up to date on the topics that interest you, plus you’ll be able to make connections who are looking to collaborate, exchange ideas and more.

Join us Not now

Community Rules & Guidelines