A while ago someone (could have been sidewinder?) was asking about the charactistics of the crabtree C50 range. My undertstanding had always been patchy;
I knew the older ones had white writing and were rated at 3ka and were type 2
I knew they then started making them with yellow writing and these were rated to 4.5ka
I knew that at least upto recent you could still buy them and your'd get a breaker with yellow writing, rated to 4.5ka and conforming to 60898 type C
(this information is thrown up by a google search)
I did not know why they had suddently switched from type 2 to type 3/C
And I also presumed all yellow writing breakers were type C
I then came across a site which had some breakers I knew were installed prior to the mid 1980's which were yellow. These could not be to 60898 as the standard simply did not exxist back then (certainly not in the uk anyway), so were these 3871 type 3s? or were they still type 2s?
Then it suddenly occured to me that the type had little to do with the colour change, that was intended to signify breaking capacity only and crabtree did not delibratly move away from making type 2 breakers. I would hazard a guess that all crabtree C50 breakers are "probably" type 2 in nature. [that is having a magnetic trip in the range of 4*In to 7*In] but having it set towards the higher end of this range.
Equipment could still designed to 3871 upto 1994, and if it was designed before a certain date it could still be sold upto as late as 1999, after 1999 all breakers being sold new must be to BSEN 60898. which have the types as follows,
B - 3*In to 5*In, C-5*In to 10*In, D-10*In to 20*In
Now if a firm were producing a breaker in the 80's that took 6*In to trip and selling it as BS3871 type 2 and suddently had 60898 forced upon them, then perhaps they would send it for be-certification to the new standard and suddently have a 60898 Type C with more restrictive Zs values.....
Now I have not had this confirmed by crabtree, but it seems very likely to me, in which case as BS7671 allows you to refer to manufacturer max zs values, then type 2 zs values would be appropiate for new ones even ones now supplied in a box which says 60898 type C.
This was all prompted by finding a load of these in a pub on an EICR, it still was unsatsifactory before you ask, I took exception to the kictchen ring being on a 40A breaker which still kept tripping out due to the amount of commericial catering equipment on it.... along with a load of other faults
I knew the older ones had white writing and were rated at 3ka and were type 2
I knew they then started making them with yellow writing and these were rated to 4.5ka
I knew that at least upto recent you could still buy them and your'd get a breaker with yellow writing, rated to 4.5ka and conforming to 60898 type C
(this information is thrown up by a google search)
I did not know why they had suddently switched from type 2 to type 3/C
And I also presumed all yellow writing breakers were type C
I then came across a site which had some breakers I knew were installed prior to the mid 1980's which were yellow. These could not be to 60898 as the standard simply did not exxist back then (certainly not in the uk anyway), so were these 3871 type 3s? or were they still type 2s?
Then it suddenly occured to me that the type had little to do with the colour change, that was intended to signify breaking capacity only and crabtree did not delibratly move away from making type 2 breakers. I would hazard a guess that all crabtree C50 breakers are "probably" type 2 in nature. [that is having a magnetic trip in the range of 4*In to 7*In] but having it set towards the higher end of this range.
Equipment could still designed to 3871 upto 1994, and if it was designed before a certain date it could still be sold upto as late as 1999, after 1999 all breakers being sold new must be to BSEN 60898. which have the types as follows,
B - 3*In to 5*In, C-5*In to 10*In, D-10*In to 20*In
Now if a firm were producing a breaker in the 80's that took 6*In to trip and selling it as BS3871 type 2 and suddently had 60898 forced upon them, then perhaps they would send it for be-certification to the new standard and suddently have a 60898 Type C with more restrictive Zs values.....
Now I have not had this confirmed by crabtree, but it seems very likely to me, in which case as BS7671 allows you to refer to manufacturer max zs values, then type 2 zs values would be appropiate for new ones even ones now supplied in a box which says 60898 type C.
This was all prompted by finding a load of these in a pub on an EICR, it still was unsatsifactory before you ask, I took exception to the kictchen ring being on a 40A breaker which still kept tripping out due to the amount of commericial catering equipment on it.... along with a load of other faults
Last edited by a moderator:
