Fuse problem

[t1981]

Hello, have a question.
Yesterday in office I work fuse BS1361 45A was blow.
How everything is connect:

From box WYLEY cat nr. 108M (60A) BS 5419, someone take feed to another fuse board, that board is divided to two parts, one of them is strange (for me) protect by 63A RCD. My concern is - that rcd protect 4 x type b 20A fuses, and one B 32A. Two weeks ago we start to heat offices and as far I calculate we use 9 electric heaters around 2500 W each. As far I understand that RCD should not by bigger (63A) than BS1361 (45A). Is that possible that fuse blow because we use to much current in this same time? Thanks for help

 

[telectrix]

9 heaters at 2500w = 9x11A = 99A. a little bit of an overload for 45A methinks.

 

[SimpleSimon]

Especially in this weather where they are going to be run for hours a day. What office do you work in??