Crabtree Breaking capacity

[Duncan Bennett]

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Can anyone tell me where I can find the breaking capacities of Crabtree BS3871 type 1 MCB's. The installation has to be 20+ years old and there are no Device designation marks on the breakers themselves :confused5:

 

[Knobhead]

If the lettering is white then 3KA, yellow 4.5KA

 

[Engineer54]

MCB's used to be designated from M1 to M9. The numeral designates the breaking capacity.
eg ...M6 = 6 KA

 

[Duncan Bennett]

MCB's used to be designated from M1 to M9. The numeral designates the breaking capacity.
eg ...M6 = 6 KA

Thanks Engineer. Yes, I usually get the figures from 7.2.7(i) of the OSG, but there are no figures on these breakers :-(

 

[Duncan Bennett]

If the lettering is white then 3KA, yellow 4.5KA

Hi Tony. Mines would be different of course - they're black on grey!! Pics attached.

 

[MarkieSparkie]

Hi Duncan, The Crabtree SB6000, Type 1, MCBs, (early versions black letting on grey body and later versions green lettering on grey body) are M6 (6kA) rated. If you remove the MCB from it's busbar, you can confirm this, the specification details are moulded into the right-hand-side (looking from the front) of the device.

 

[Swicade]

got some old ones similar to that in the shed...just checked them and they have M6 stamped into the molded case on the side of the breaker.

The writing on the front of the breakers is in Grey and i'd guess they're about 12 year old Crabtree Starbreaker i have here (they were spares from when i bought and rewired the house i live in)

Seem to remember the writing on the front was all in green before grey.....breaking capacity etc was also stamped on the side but cant remember what value's they were (getting old....)

 

[Swicade]

Damn my slow typing.....Basicaly what MarkieSparkie said

 

[Duncan Bennett]

Many thanks, Markie & Swicade; saved me the job of going back to the job and taking one out :mellow:

 

[MarkieSparkie]

Your welcome mate, glad to have helped.

 

[Taylortwocities]

What's your problem, mate. Is your PSCC 10KA or something?