Stephen Johnson
Hi John, There are numerous different shapes and formats of MCB's, generally depending on their age and use. Some manufacturers MCB's will fit well in other manufacturers distribution boards, whilst MCB's of the same type and rating will be manufactured to the same electrical standard they are not manufactured to all be interchangeable. To ensure correct operation it is always preferable to replace an MCB with one from the same manufacturer. If in any doubt at all please do consult a qualified electrician. I hope that helps Kind regards Steve
