Advice needed

[davedwr1978]

Hi

i just applied to join trainee electrician group but haven't heard nothing yet, I have a college question but I am unsure of what kind of info they want me to look for can someone help me, the question is.

.the proposed design for this installation includes the following protective devices;

. BS EN 60898 type D circuit breaker for a mig welder
. MCCB rated at 125A for the distribution circuit to the DB2


determing using manufacturers information whether discrimination will be achieved?

 

[Sintra]

Hi you have access to the trainee forum and I have moved this thread for you. My advice would be for you to attempt the question yourself then I'm sure some of the guys will give you pointers from there.

 

[trev]

Hi Dave.
Post up the full question together with your attempt at it, we'll then pull it to bits and tell you where you're going wrong (if you are)
Don't worry, we're not going to take the **** if you get it wrong. That's not how we do things in this bit of the forum.
Welcome aboard btw

 

[ElectroChem]

Hi Dave,

I've uploaded a figure from my AS3000, the Australian Wiring Rules. Your regs book (Big Red Book I think it's called?) or college materials should have a similar diagram. You'll need to look up what are called the time-current or inverse-time characteristic curves of the relevant protective devices.

 

[Resu]

Hi Dave,

I've uploaded a figure from my AS3000, the Australian Wiring Rules. Your regs book (Big Red Book I think it's called?) or college materials should have a similar diagram. You'll need to look up what are called the time-current or inverse-time characteristic curves of the relevant protective devices.

View attachment 27431

Slightly off topic, it's the Big Green Book, soon to be replaced by the Big Yellow Book (I think!). [emoji106]

 

[Simonslimline]

Hi

i just applied to join trainee electrician group but haven't heard nothing yet, I have a college question but I am unsure of what kind of info they want me to look for can someone help me, the question is.

.the proposed design for this installation includes the following protective devices;

. BS EN 60898 type D circuit breaker for a mig welder
. MCCB rated at 125A for the distribution circuit to the DB2


determing using manufacturers information whether discrimination will be achieved?

What is the In of the type D 60898?

Have a look at Appendix 3 in BS7671, BGB.

 

[Baker1988]

I had this question and it was a 16A type D 60898 and I'm sire it worked out that discrimination was not achieved (but I'm not sure really) also you have to go online and find the manufacturing data for the mccb and print it off