Federal electric rcbo!

[Chrisprice90]

Been carrying out an eicr and have for the first time come across a federal electric 40a 30ma rcbo. I am struggling to find the maximum Zs value. Can anyone help?

 

[KEV 1 N]

What type is it? Any BS numbers on it?

 

[Chrisprice90]

Not sure on type. It's to bs 4293. They are completely obsolete.

 

[KEV 1 N]

The BS4293 refers to the rcd side, the over current will be BS3871.
Take your pick.

 

[Richard Burns]

I have a reference that states the max Zs for a 40A Federal Electric Stablok MCB is 0.32 which would make it similar to a type D breaker at an instantaneous trip of max 18*In.
However I do not know if yours is a stablok type.
Also as it is a 30mA RCBO then the max Zs is 1667Ω!

 

[KEV 1 N]

Not sure on type. It's to bs 4293. They are completely obsolete.

Just had a look on eBay, there are plenty for sale, good prices 2nd hand. Some new for £60. Assuming your type is the stablock

 

[Chrisprice90]

The one installed seems to be functional. I just needed the zs for my certificate. I think I need to investigate which type it is and treat it as a bs 3871 for over current . Thanks guys

 

[KEV 1 N]

What was your Zs reading? If it's lower than the value for type 3, then at least it's going to be under the limit for whatever type it is. Unless its type 4....0.09ish ohms

 

[westward10]

The one installed seems to be functional. I just needed the zs for my certificate. I think I need to investigate which type it is and treat it as a bs 3871 for over current . Thanks guys

What colour toggle is it, black type 4, orange type 3, green type 2 and the rarest of all, white type 1. Personally I wouldn't worry too much about the max Zs as it is an rccb but you should enter the correct type on the schedule.

 

[westward10]

The original maximum Zs for a type 4, 40A Federal device are 0.48 for 0.4 sec and 1.10 for 5 sec, this is from Federal Electric data but now may be different as this is not based on 230v. Type 4 are like fuses and had two different values for 0.4 and 5 sec disconnection. Figures have never been quoted in any IEE / IET Regulations and manufacturers data should be sought as there are huge variations between each manufacturer. They cannot be compared to a Type D they are totally different.

 

[westward10]

If you are unsure of its type post up a pic if possible and I will confirm.

 

[westward10]

Just to add if it is one of the latter types with white casings they are 60898 but can be identified in a similar way by the toggle colour. Green type B, orange type C and brown/black type D.

 

[Chrisprice90]

I have attached a picture

View attachment 38898

 

[westward10]

Sorry can't open it.

 

[Chrisprice90]

I'll try again

 

[westward10]

Most rcbos provide three functions, fault/overcurrent/rcd protection but one you have only provides overcurrent and rcd protection, hence it has no Type as such because the fault protection is provided by the rcd part of it so it is a bit of an oddity. You can only enter on the schedule BS4293 with no Type. Don't forget trip times at x1 should not exceed 200ms with 40ms for x5.

 

[Chrisprice90]

Appreciate the help westward10

 

[freddo]

I'm impressed you have found one that trips, I've never come across one that trips, either with the test button or an RCD tester.

 

[Chrisprice90]

I was very surprised myself that it works !