Re: practical exam theory
 

hi all,

from the drawing that dune put up where would you wire the emergency stop and are them 2 drawings all they are after or is more needed, any help appreciated thanks

Re: practical exam theory
 

Ye mine all done . Exam not to bad . Learn your power formulas and ohms law v= I x r etc. they ask health and safety and basic scenarios that any sparky should know. I had a question to work out current carrying capacity and voltdrop. Resistors in parallel and series. The dol starter they ask you to draw a diagram for the control and power circuit . Then u have wire it up. The one we had was like the ones you buy in the wholesaler with the start and stop button one it . It's basically mounted on the wall and u have to wire it and add a emergancy stop to it. The em stop button is mounted on the wall next to the dol . Just make sure once it all wired that hold on contact (13+14) is wired in parallel to the start button or else the motor won't start and run. Everyone got stuck on that . But the guy lets u try till u get it right in ur time frame obviously . They very helpful. If u follow ur diagram u will be fine. I had a 3 phase contactor with a 3 phase coil. R u doing urs with future skills? Mine was in Tottenham London .

Re: practical exam theory
 

U wire it anywhere in the control circuit in series. For example for 3 phase contactor and 3 phase coil. Take wire from. Any phase to ur start button. A wire from other side of ur start button to one side of ur em stop . A wire from other side of em stop to 95 of ur thermal overload. A wire from 96 of thermal overload to A2. Then wire ur hold on or aux contact in parallel to ur start button. So a wire from one side of ur start button to 13 and another from the other side of ur start button to. 14 . Then u take a wire from a different phase to A1 .
This applys to a bog standard dol starter that u buy from the wholesaler. The only thing with those is that the 96 terminal in already internal linked to A2. Try get ur hands on one of them and a em stop button, wire it up and see if works . Then u should be fine.

Re: practical exam theory
 

That's the one I had

Re: practical exam theory
 

Those 2 drawings r fine

Re: practical exam theory
 

hi,

well done for passing exam, cheers for that info earlier but to be honest im still struggling with it all, do u have or know where i can get any drawings for the power and control circuits with an em stop so i can get my head round it.

cheers

Re: practical exam theory
 

Hi mate. If go to page 15 of this thread there some links to loads of usefull info on dol starters some one put up. Explains exactly how it works and drawings.

Re: practical exam theory
 

Drawings I used. Just remember if there's no neutral for the power circuit use a another phase for A1 providing its a 3 phase coil.

Re: practical exam theory
 

2

Re: practical exam theory
 

3

Re: practical exam theory
 

U can also buy a book on e bay called electrical calculations by aj Watkins for bout £12 . Really helpful for the theory. .

Re: practical exam theory
 

hi,

ye thanks for that helped a great deal things are starting to click now cheers, any other tips for the theory or other parts of exam cheers mate

Re: practical exam theory
 

Sorry Crg, only just looked at this. Do you want to check the latch for the start signal. Contact should be n/o on 13/14.

Re: practical exam theory
 

Oh ye sorry mate . Drew it up I a rush to help another guy. Cheers for spotting that .

Re: practical exam theory
 

Thought so, cos you have it right in the overall pic :lol:

Have you had your results yet?