College Project, help please!

[Zinimoore]

Hi

I'm currently an electrical apprentice and have a project due in about five months. The quick version is: I have an isolator, D.O.L starter and 3 phase motor in circuit (not on mains) I need to introduce 10 faults between each piece of equipment, all wired to toggle switches on the trunking underneath.

What I need help with is making these faults (maybe with resistors). Any input would be great but what I really need is a wiring diagram.

Thanks in advance.
Brett

 

[accordfire]

Hi

I'm currently an electrical apprentice and have a project due in about five months. The quick version is: I have an isolator, D.O.L starter and 3 phase motor in circuit (not on mains) I need to introduce 10 faults between each piece of equipment, all wired to toggle switches on the trunking underneath.

What I need help with is making these faults (maybe with resistors). Any input would be great but what I really need is a wiring diagram.

Thanks in advance.
Brett

What have you come up with so far? A list of the faults you want to introduce, for example?

Don't get me wrong, no problem helping, but it's your homework, and it'd be nice to see how far you've managed without simply getting others to do it - don't take offence, I don't mean you haven't tried, I just mean it's nice to see you have.

It's about you learning something, after all, and the best way of doing that is telling us what you THINK you should be doing - so we can either correct it, or advise you, or tell you that you've got it right.

Post away, friend, and let's see if we can't help you along....

 

[Zinimoore]

Well so far this is what I have:
I will need a terminal box with the 3 phase and earth coming from the isolator and the same coming from the starter. There will be 10 toggle switches in the trunking, when they are all down the circuit must be faultless but when one or more are flicked they will have designated faults.
The 10 faults I want to put in are: between phases on the isolator (3)
between Earth and three phases on isolator (3)
each phase between isolator and starter (3)
finally Earth continuity

I will have a randon mixture of short circuits, high/ low resistance.

I hope this has cleared up a little bit, thanks
Brett

 

[accordfire]

Well so far this is what I have:
I will need a terminal box with the 3 phase and earth coming from the isolator and the same coming from the starter. There will be 10 toggle switches in the trunking, when they are all down the circuit must be faultless but when one or more are flicked they will have designated faults.
The 10 faults I want to put in are: between phases on the isolator (3)
between Earth and three phases on isolator (3)
each phase between isolator and starter (3)
finally Earth continuity

I will have a randon mixture of short circuits, high/ low resistance.

I hope this has cleared up a little bit, thanks
Brett

Okay - that's good. You've got a clear design brief.

Now have a go at drawing a circuit diagram for any one fault at a time - post it up and we'll see what you know.

Earth continuity is quite straightforward, and so is high resistance on a phase, or on the earth.

Don't worry too much about using correct symbols for now - the point is to get an understanding of what you know.

The basic thing here is not to consider all ten faults at the same time, but to introduce one fault at a time, get that right, and move on to the next one. That way, you only have one problem to consider at a time if anything is wrong.

We'll see how far you get, and then we can polish it all up.