Davey Jones Posted July 22, 2007 Share Posted July 22, 2007 It also looks like its going to shake is everything firmly secured down relays really aren't for inductive loads and some work great others stick after time thats too hit and miss for me, what rating is your relay (Amps) Link to comment Share on other sites More sharing options...
Themadhippy Posted July 22, 2007 Share Posted July 22, 2007 (edited) Only the electric board are allowed to use the same conductor for neutral and earth youve not worked on a tn-c system ( earthed concentric)then? very rare i'll admit,but theres the odd 1 or 2 still out there. It's on these installations were no switching of the neutral is permited,as the neutral is also the earth. edit to add I'd geuss by looking at the relay that is olny rated for 250w inductive Edited July 22, 2007 by Themadhippy Link to comment Share on other sites More sharing options...
Davey Jones Posted July 22, 2007 Share Posted July 22, 2007 Yeah I have worked on loads of places that are TNC-S its very common also known as PME but only the electric board are allowed to combine the neutral and earth. As a spark we only use the seperate terminals supplied. I can honestly say I have never and would not use the same core as a neutral and earth if we lose the neutral link all steel work and pipes will be at mains potential. I hope you haven't done this before TMH it is very dodgy. Link to comment Share on other sites More sharing options...
Themadhippy Posted July 22, 2007 Share Posted July 22, 2007 (edited) TN-C, not TNC-S, perfectly safe as long as you follow the regs,and yep ive worked on a couple,on the first we had to contact NICEIC for advice as we thought it was dodgy Edited July 22, 2007 by Themadhippy Link to comment Share on other sites More sharing options...
dub_lover Posted July 22, 2007 Share Posted July 22, 2007 It also looks like its going to shake is everything firmly secured down relays really aren't for inductive loads and some work great others stick after time thats too hit and miss for me, what rating is your relay (Amps) I hope it won't shake that much - it will sit on the floor oustide of the grow-box. 10A - should do the trick. At least it should be better than pluging directly into the timer! I have done one grow with it before and certainly had no problems that time. I might just take a quick butchers at the contacts now you mention it though! Link to comment Share on other sites More sharing options...
Themadhippy Posted July 22, 2007 Share Posted July 22, 2007 (edited) 10A - should do the trick but thats 10A for a resitive load,not inductive, 1/3hp is the inductive load or 248 watts Edited July 22, 2007 by Themadhippy Link to comment Share on other sites More sharing options...
Davey Jones Posted July 22, 2007 Share Posted July 22, 2007 TN-C, not TNC-S, perfectly safe as long as you follow the regs,and yep ive worked on a couple,on the first we had to contact NICEIC for advice as we thought it was dodgy Yeah TMH I know wot u mean now this is where the whole place has the earths connected to the neutral terminal I have never seen this and I think you were right to contact the NIC, what did they say are you allowed to add on to this. It certainly not the best is it Link to comment Share on other sites More sharing options...
Davey Jones Posted July 22, 2007 Share Posted July 22, 2007 I hope it won't shake that much Most people on here don't like hopeing it will be ok, it certainly wouldn't be good enough for me. While your on look at some DIN rail too this will do the job right. Link to comment Share on other sites More sharing options...
dub_lover Posted July 22, 2007 Share Posted July 22, 2007 but thats 10A for a resitive load,not inductive, 1/3hp is the inductive load or 248 watts I don't understand what "1/3hp" means. I do understand that the overhead required for an inductive load is much greater than for a resistive one because of the voltage spike as the coil self-induces currents, but I do not understand how the 248W figure is arrived at? This is approximately only 10% of the 2.3kW maximum for the resistive load (230V x 10A). Please could you explain, or provide a link explaining? Could I allieviate the problem with a "snubber" or would this affect the operation of the ballast? More importantly, I just bought the relay that's itemised in the first post in this sticky thread! Does this mean that many users are using an incorrectly rated component in their rigs? I know that there is that electrical disclaimer, but this is slightly worrying to me! Maybe you need to alert the Mods to this? Link to comment Share on other sites More sharing options...
Davey Jones Posted July 22, 2007 Share Posted July 22, 2007 I don't understand what "1/3hp" means. 1/3 horse power one horse power is approx 750 W and your the one with physics I do understand that the overhead required for an inductive load is much greater than for a resistive one because of the voltage spike as the coil self-induces currents, but I do not understand how the 248W figure is arrived at? This is approximately only 10% of the 2.3kW maximum for the resistive load (230V x 10A). Please could you explain, or provide a link explaining? TMH just guessed your wattage only you can tell us that Could I allieviate the problem with a "snubber" or would this affect the operation of the ballast?More importantly, I just bought the relay that's itemised in the first post in this sticky thread! Does this mean that many users are using an incorrectly rated component in their rigs? I know that there is that electrical disclaimer, but this is slightly worrying to me! Maybe you need to alert the Mods to this? Why bother with a snubber that probably won't work when all you need is a contactor, and if you read the thread you will see that it says this is no good for the job so yeah whoever used it is not necessarily using wrong components just components that are not likely to work well for long. Maybe if I take the time to do a thread then the mods will stick it up maybe a mod could give me the confirmation they want one here. Link to comment Share on other sites More sharing options...
dub_lover Posted July 22, 2007 Share Posted July 22, 2007 1/3 horse power one horse power is approx 750 W and your the one with physicsTMH just guessed your wattage only you can tell us that Why bother with a snubber that probably won't work when all you need is a contactor, and if you read the thread you will see that it says this is no good for the job so yeah whoever used it is not necessarily using wrong components just components that are not likely to work well for long. Maybe if I take the time to do a thread then the mods will stick it up maybe a mod could give me the confirmation they want one here. I did think that hp stood for horsepower, but as 1/3hp bore no relation to the power that I'm using (400W HID plus a small fan to cool the lamp) I thought it might have been some obscure abbreviation in relation to something else! I did also say what my power usage was on the previous page.... but that's the problem with the 'net - many people throw in their 2 cents worth without reading what's been said previously On that note, as it would seem that the discussion is rambling somewhat and I am dubious as to the value it's having for all and sundry, I'll stop interrogating you, EM2 ! I will try to source a relay with better contacts though - it does sound like it might be an issue in the future... ...as for my wiring, that'll just stay the same! hehe. Thanks for the advice! Link to comment Share on other sites More sharing options...
Themadhippy Posted July 22, 2007 Share Posted July 22, 2007 1/3 hp=248 watts,the maximum load of that relay for a motor,motors are almost purley inductive,very much like a ballast,so without seeing the manufacters specs i wouldnt use that particular relay for anything more than 250w,the relays ive used in the past look identical but are rated for 2A inductive think you were right to contact the NIC, what did they say are you allowed to add on to this. yea they explained everything and refered us to the relavent regs ,i seem to recall they inspected it as part of annual inspection as there not that comon Link to comment Share on other sites More sharing options...
Davey Jones Posted July 22, 2007 Share Posted July 22, 2007 I did also say what my power usage was on the previous page.... but that's the problem with the 'net - many people throw in their 2 cents worth without reading what's been said previously Thats a bit cheeky, you throwing your 2 cents worth without reading previous properley we heard you using 400W but asked what rating your relay was TMH simply guessed based on the size of your relay so what is the relays rating I will try to source a relay with better contacts though - it does sound like it might be an issue in the future......as for my wiring, that'll just stay the same! hehe. Thanks for the advice! Its a contactor you need not a relay do you know what one is? Link to comment Share on other sites More sharing options...
Davey Jones Posted July 22, 2007 Share Posted July 22, 2007 yea they explained everything and refered us to the relavent regs ,i seem to recall they inspected it as part of annual inspection as there not that comon They certainly not, have you seen the IT system this is the other one I have never seen apparently you need a permit from the home office to install it. Link to comment Share on other sites More sharing options...
Themadhippy Posted July 22, 2007 Share Posted July 22, 2007 have you seen the IT system yep use them alot ,but from a genarator.It gets confussing as we have to follow BS7909 for most things,but BS76712 for others Link to comment Share on other sites More sharing options...
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