Clintrose123 0 Report post Posted February 11 Hi I’m Clint. im new to this forum, I currently study electrical at college and am 4 months into my 1st year 0 Share this post Link to post Share on other sites
Evans Electric 2,937 Report post Posted February 12 Hi Clint , welcome to the Forum . How's the first year at college going ? Have you managed to get an apprenticeship with a company ? 0 Share this post Link to post Share on other sites
Doc Hudson 1,159 Report post Posted February 12 On 11/02/2019 at 21:01, Clintrose123 said: Hi I’m Clint. im new to this forum, I currently study electrical at college and am 4 months into my 1st year Welcome to the forum Clint, 4 months into your 1st year? That sounds as though you are adopting a sensible approach to attaining electrical qualifications, i.e. a proper full college course. If you had opted for a 5WW short course, you would have finished about two and half months ago with "Full DI qualifications", {probably including PAT}" and be out there earning £80,000 p/a with a fleet of vans, one for each day of the week. So they say! Just to advise, if/when you find you are struggling with a college question or understanding about some part of the wiring regulations, Don't hesitate to ask on here for advice. But, do make sure you offer your suggestion as to what you think the answer should be first. As we are not a homework answering service, And most members are willing to offer advice and help, but it is an enormous help when wording our answers if we understand what your current level of knowledge is to start with. Doc H 2 Share this post Link to post Share on other sites
Clintrose123 0 Report post Posted February 14 On 12/02/2019 at 22:52, Doc Hudson said: Welcome to the forum Clint, 4 months into your 1st year? That sounds as though you are adopting a sensible approach to attaining electrical qualifications, i.e. a proper full college course. If you had opted for a 5WW short course, you would have finished about two and half months ago with "Full DI qualifications", {probably including PAT}" and be out there earning £80,000 p/a with a fleet of vans, one for each day of the week. So they say! Just to advise, if/when you find you are struggling with a college question or understanding about some part of the wiring regulations, Don't hesitate to ask on here for advice. But, do make sure you offer your suggestion as to what you think the answer should be first. As we are not a homework answering service, And most members are willing to offer advice and help, but it is an enormous help when wording our answers if we understand what your current level of knowledge is to start with. Doc H Sorry for the delay in getting back in touch, also thank you for your reply! Yeah im doing a proper course at college. I’ve been told by my tutor that my next assignment will be about contactors and what they can do. i have a had a brief look at these now and already under it is some sort of magnetic switch which given power from between 12v-230v it then closes the contact and in return gives power to what you have connected to the contactor? I dont understand how these can help when you have big lighting loads? How would these be used on shop lights ? I want to try get my knowledge up on these before my new assignment to help myself ! 0 Share this post Link to post Share on other sites
Tony S 488 Report post Posted February 14 Have a look in "knowledgebase" on this forum. 0 Share this post Link to post Share on other sites
Doc Hudson 1,159 Report post Posted February 14 1 hour ago, Clintrose123 said: Sorry for the delay in getting back in touch, also thank you for your reply! Yeah im doing a proper course at college. I’ve been told by my tutor that my next assignment will be about contactors and what they can do. i have a had a brief look at these now and already under it is some sort of magnetic switch which given power from between 12v-230v it then closes the contact and in return gives power to what you have connected to the contactor? I dont understand how these can help when you have big lighting loads? How would these be used on shop lights ? I want to try get my knowledge up on these before my new assignment to help myself ! Have you ever looked really close at a typical light switch in your home, especially some of these modern budget brands with very thin plastic construction? And if they are still operating traditional non-energy saving lamps, you will often see a, (sometimes quite significant), spark as the contacts break and make while turning the load off/on. You have to remember a basic principal that all switches have to be mechanically robust enough to withstand any arcing and sparking that occurs as they operate turning loads on/off. To have switches robust enough for larger loads, so the contacts don't burn themselves out or weld themselves together, would mean the physical switch needs to be too large to be accommodated at the location where they need to be controlled from, and would certainly need a bit more physical effort to manually operate. Are you familiar with how relays are used in automotive wiring so that very delicate finger touch switches can turn on larger loads? i.e. dashboard or steering stalk switch operates a relay needing very small current, and the relay using a magnetic coil can pull a pair of larger high power contacts, that can turn on all sorts of accessories e.g. heated rear window. So what do you think a contactor can do with mains voltage loads and how is the contactor operated. Doc H. 0 Share this post Link to post Share on other sites
Evans Electric 2,937 Report post Posted February 15 Look at it like this Clint , I used to do a lot of Barclays Banks , many of them had a small key switch or button at the final exit that worked a fairly big contactor . The contactor turned off all the lights & sockets etc except the necessary stuff . So you didn't have to your the building every night , switching stuff off everywhere. Some areas would be secure so you couldn't get in anyway . You can't switch all that stuff off with one little 5A switch at the door.. the 5A switches the contactor , the contactor switches the loads . 0 Share this post Link to post Share on other sites
Clintrose123 0 Report post Posted Sunday at 10:21 On 14/02/2019 at 23:30, Doc Hudson said: Have you ever looked really close at a typical light switch in your home, especially some of these modern budget brands with very thin plastic construction? And if they are still operating traditional non-energy saving lamps, you will often see a, (sometimes quite significant), spark as the contacts break and make while turning the load off/on. You have to remember a basic principal that all switches have to be mechanically robust enough to withstand any arcing and sparking that occurs as they operate turning loads on/off. To have switches robust enough for larger loads, so the contacts don't burn themselves out or weld themselves together, would mean the physical switch needs to be too large to be accommodated at the location where they need to be controlled from, and would certainly need a bit more physical effort to manually operate. Are you familiar with how relays are used in automotive wiring so that very delicate finger touch switches can turn on larger loads? i.e. dashboard or steering stalk switch operates a relay needing very small current, and the relay using a magnetic coil can pull a pair of larger high power contacts, that can turn on all sorts of accessories e.g. heated rear window. So what do you think a contactor can do with mains voltage loads and how is the contactor operated. Doc H. Thanks again for anothe reply, I haven’t really looked up much about relays but I think I will try look this up. Still trying to get my head around these contactors, i think I’m over thinking a lot into it and it’s beginning to confuse me. Do you have any material which would help me get a better understanding? On 15/02/2019 at 01:35, Evans Electric said: Look at it like this Clint , I used to do a lot of Barclays Banks , many of them had a small key switch or button at the final exit that worked a fairly big contactor . The contactor turned off all the lights & sockets etc except the necessary stuff . So you didn't have to your the building every night , switching stuff off everywhere. Some areas would be secure so you couldn't get in anyway . You can't switch all that stuff off with one little 5A switch at the door.. the 5A switches the contactor , the contactor switches the loads . Thank you for the reply, am I to believe that this “big contactor” would be fed from a dB which could potentially take upto 40amps to help hold all this load of lights? You also speak of a last man switch so everything is turned off but not taking all the load, am I to be believe this could be wired in 1.5mm T&E back to the contactor which would connect to A1? Which is the live to the coil which would then open then contact, killing all the power to these lights? please tell me if I have gone off topic and if I have it wrong any corrections to the right direction would be great. thank you all 0 Share this post Link to post Share on other sites
Evans Electric 2,937 Report post Posted Sunday at 15:01 4 hours ago, Clintrose123 said: ou also speak of a last man switch so everything is turned off but not taking all the load, am I to be believe this could be wired in 1.5mm T&E back to the contactor which would connect to A1? Which is the live to the coil which would then open then contact, killing all the power to these lights? please tell me if I have gone off topic and if I have it wrong any corrections to the right direction would be great. I think thats what I just said . 0 Share this post Link to post Share on other sites
Clintrose123 0 Report post Posted Sunday at 19:38 (edited) 4 hours ago, Evans Electric said: I think thats what I just said . Sorry I guess my only input in what you said to me was, would the 1.5mm from the main cut out switch to the contactor be connected to A1? my next questions, would you just take all your switch wires back to this contactor? If so, how would these be able to be independently switched ie, if the customer wanted the staircase lights to have its own switch, but also switched off from this main switch at night . Also, if you had a 40amp contactor, would the load whichh you wire into these (lights) need to have CSA adequate enough to carry 40 amp? Edited Sunday at 19:44 by Clintrose123 0 Share this post Link to post Share on other sites
Evans Electric 2,937 Report post Posted Sunday at 22:58 The coil that operates the contactor is across a1 & a2 . Its voltage could be anything from 12 - 24- 50 - 110 - 240 - 415 V . The usual way to do what I described would be to switch the power to a non - essential Dist.Bd. 0 Share this post Link to post Share on other sites
Clintrose123 0 Report post Posted Monday at 14:04 15 hours ago, Evans Electric said: The coil that operates the contactor is across a1 & a2 . Its voltage could be anything from 12 - 24- 50 - 110 - 240 - 415 V . The usual way to do what I described would be to switch the power to a non - essential Dist.Bd. So I’ve been going through some of my stuff with my college tutor today and praised me for going out looking for this information before the assignment has started. He said I’ve got the understanding of the contactor, but he thinks I’m getting lost when it’s coming to doing the switching of things do do you have anything that I can read upon this to help grasp this? also, you said “to switch the power to a non - essential Dist.Bd” can you draw this out to see see if I understand it better? If not it’s fine, I appreciate the responses 0 Share this post Link to post Share on other sites
Evans Electric 2,937 Report post Posted Monday at 14:33 There you are Clint , any more homework you'll have to do yourself mate 1 Share this post Link to post Share on other sites
kerching 2,061 Report post Posted Monday at 15:21 Deke.....which CAD program are you using? 0 Share this post Link to post Share on other sites
Clintrose123 0 Report post Posted Monday at 19:16 4 hours ago, Evans Electric said: There you are Clint , any more homework you'll have to do yourself mate Hehe, I honestly can’t thank you enough. I understand now a lot better. I had pictured all so differently in my head. I assume the little symbol which you have taken off one of the phases is a breaker? Once again thank you! Dont worry I won’t use this to take credit from my tutor 0 Share this post Link to post Share on other sites
Evans Electric 2,937 Report post Posted Monday at 20:14 4 hours ago, kerching said: Deke.....which CAD program are you using? Its a new one Kerch , very technical , you wouldn't understand , you have to be an IT officianado like myself ...its called A4 & pencil 0 Share this post Link to post Share on other sites
Evans Electric 2,937 Report post Posted Monday at 20:20 57 minutes ago, Clintrose123 said: Dont worry I won’t use this to take credit from my tutor No probs Clint . Everyone on here will help with general electrical questions etc, but there,s a few who try to get each weeks homework / college work done , which doesn't help anyone TBH. 0 Share this post Link to post Share on other sites
Clintrose123 0 Report post Posted Monday at 20:40 16 minutes ago, Evans Electric said: No probs Clint . Everyone on here will help with general electrical questions etc, but there,s a few who try to get each weeks homework / college work done , which doesn't help anyone TBH. That’s good to know, an nah I’d rather ask the questions and get the understanding through that way. As I’m only going to cheat myself! Do you know any website which has good revision material which would be of good use to me? 0 Share this post Link to post Share on other sites
Evans Electric 2,937 Report post Posted Monday at 20:45 Someone will , keep looking ..... dinosaurs were roaming outside the college when I was there last . 0 Share this post Link to post Share on other sites
kerching 2,061 Report post Posted Monday at 20:59 42 minutes ago, Evans Electric said: Its a new one Kerch , very technical , you wouldn't understand , you have to be an IT officianado like myself ...its called A4 & pencil I thought I recognised it HB Staedtler BASIC i think 0 Share this post Link to post Share on other sites
Evans Electric 2,937 Report post Posted Monday at 21:01 (edited) Ah! You have it too then !! Did you have the early version .... Word for Woodbine & Biro ....better known as "Back 'o the fag packet" Edited Monday at 21:03 by Evans Electric 0 Share this post Link to post Share on other sites
Doc Hudson 1,159 Report post Posted Monday at 23:03 2 hours ago, Evans Electric said: Ah! You have it too then !! Did you have the early version .... Word for Woodbine & Biro ....better known as "Back 'o the fag packet" Didn't Word for Woodbine XP-Pro version 3.1 come with the added features of a Pencil Sharpener and Genuine India Rubber Eraser? And 3.2 allowed the bolt-on Spell-checker, AKA Collins Gem pocket dictionary to be used with it as well. Those were the days when estimates and circuit designs were done the traditional hand-crafted way. (probably in the van outside the wholesaler before going in to ask for all the bits you have just designed). Doc H. 0 Share this post Link to post Share on other sites
Evans Electric 2,937 Report post Posted Tuesday at 00:03 You remember them all too well Doc. 0 Share this post Link to post Share on other sites