Type B, C or D

[Bros]

What is the difference as it refers to another standard AS 60898. Why I am asking is I have to run a 15A circuit 75M, well 4mm just makes it on voltage drop but it needs to have a "B" circuit breaker.

[Hitchy]

A,B, or D type CB's refer to the trip curve or time curve of that specific breaker.

Is that what you mean?

[Bros]

No A, just B, C and D refer to table B1 pg 351 AS 3000. I suspect it is the trip curve but not sure.

[chrisp]

I'm pretty sure that it is the trip curve. i.e. Type = trip-curve

[Hitchy]

No A, just B, C and D refer to table B1 pg 351 AS 3000. I suspect it is the trip curve but not sure.

Sorry B,C,D don't know why I put A type, Having one of those moments I guess............................................

[LinesElectrical]

AS 60898.1 Electrical accessories – Circuit Breakers for Overcurrent Protection forhousehold and similar installations.
Theres no real useful info in this standard just lots of examples of suitable types of breakers,dimensions and testing methods.

As60898.1 3.5.17
instantaneous trip time refers to

AS60898.1 4.5
lists types eg. B,C,Dtype.

Also AS60898.1 Table two + clause 5.3.5

Type B shall trip instantly above 3In up to and including 5In.
Type C shall trip instantly above 5In up to and including 10In
Type D shall trip instantly above 10In up to and including 20In - 50In

-In refers rated current and the type (eg B,C,D) refers to how many times you multiply that to trip it instantly.

[Bros]

I'm pretty sure that it is the trip curve. i.e. Type = trip-curve

My calculations tell me I need a B. I looked at the Clipsal catalogue and the normal CB is C type they don't even have a B. AS 3000 table B1 gives 4mm 25A CB a length of 67M with "C" CB but says nothing about derating of the protective device so if I derated the CB from 25 A to 20A can I then get my 75M?

[Bros]

Type B shall trip instantly above 3In up to and including 5In.


What's that mean instantaneous between 3 and 5 times the rating?

[LinesElectrical]

Yeah a b breaker needs 3-5 times rated to trip instantly.
I wouldn't go down this route I would get a din mount HRC holder and use a BS88 fuse then you could go 93mtrs on 2.5mm at 20amps.

http://www.swecheck.com.au/catalog/129.pdf

Or just use bigger cable if it's charge up.

[Bros]

Voltage drop would put 2.5 out of the picture. It is for a voluntary organisation I "work" for so I want to keep it as cheap as possible.

[LinesElectrical]

But your using 4mm you should scrape in.
Then use a twenty amp outlet and you won't need an rcd. Saving money everywhere.
You could always just use 6mm since the price diffrence is only $40

[Bros]

But your using 4mm you should scrape in.
Then use a twenty amp outlet and you won't need an rcd.

Not one of your better suggestions as it is on a mooring pontoon as it is for Volunteer Marine Rescue Group


You could always just use 6mm since the price diffrence is only $40

I thought it would be more so I will think about it, I am going to try and scrounge some first.

Thanks all

[LinesElectrical]

Yeah probably not as3004 prohibits HRC fuses and 20amp outlets and mandates rcds in that situation. Sigh.

[Bros]

It's all academic now as I have just acquired 150m of 6mm circ twin and earth about twice what I want. It was put in by mistake instead of 16mm so I get the 6mm.
Anyone know if you can get 40mm Stainless saddles? I've seen the up to 25 mm.