smokie1 b c f c Posted July 4, 2009 Share Posted July 4, 2009 IMO anyone who doesn't use a contactor relay for anything over 150w deserves everything they get... including your house burned down!Sorry to be so sharp, but a person who grows without one, especially using HID lamps risks at the very least, a frozen timer & at the worst... a fire which could take you, your family & your neighbours house up in flames! I believe you shouldn't be able to even BUY an HID lamp without the question 'have you got a contactor relay' being asked sorry to bang on about this, but it really is poor form when you try & save a few quid by not buying one & then moan when you have bought a few packs of timers & probably spent more on replacements than the price of the ruddy contactor Let's put it another way... As growers of our precious herb in our own homes, I say we have a responsibility to others around us by taking as many precautions as we can. We may be breaking a stupid prohibition law, but FFS people neglegence shouldn't come into it!! i agree m8 totaly,wuy not av a contactor,itl just fry ya timers and maybe you. dikki Edited to add: Could this be pinned? It's a common enough question that NEEDS addressing by ALL growers 1 Link to comment Share on other sites More sharing options...
Randalizer Posted July 4, 2009 Share Posted July 4, 2009 A most excellent repost good sir! Link to comment Share on other sites More sharing options...
adarkplace Posted July 4, 2009 Share Posted July 4, 2009 not at all knowing why, just that OT1 ran some studies and found 20/4 to be best. The improvement is not huge, but the trick to growing is doing a lot of little things to help make the overall harvest better. 20/4 is just one of those many many tricks.when to go to 12/12 is a good question. Don't know the answer to that. depends on strain and style of grow. I grow from clones and let them veg for 4 weeks. I'm still experimenting with finding the optimum time for my strain. Thanks for the reply rand I think I will go 20/4 for the next week which will give them 4 weeks of veg, and then go 12/12 . adp. Link to comment Share on other sites More sharing options...
Guest cantharis Posted July 30, 2009 Share Posted July 30, 2009 I only have a 125w HID and a couple of 18w flouro tubes and they killed my Grasslin timer after a few months... So, you absolutely MUST have one with any HID I would say - I didn't think I needed one with such a small lamp - WRONG! HID lamps and ballasts are a large inductive load. When switched on, and particularly off, you get large current surges and voltage spikes. More than many a cheap timer can handle - you can weld the contacts and have your lamp stay permanently ON - not what you want during flowering. Use a contactor - basically a relay with high current rated contacts. The timer just energises the relay coil, a small load. Link to comment Share on other sites More sharing options...
Mr Greenhorn09 Posted August 3, 2009 Share Posted August 3, 2009 I have been racking my brain about these things for the past two weeks. Not sure if we need the contactor in the U.S.? I have been planning on using a timer with the following electrical rating: * 15 Amps, 1800 Watts Inductive * 500 Watts Tungsten * 125 Volts AC, 60 Hz * 1/3 HP I will be using a 400w HPS bulb so I don't think I need a large 40 amp switch like the one shown earlier in the thread. Any ideas? Would this time work safely? I am paranoid about fire. I asked the grow shop and they said they just use a surge protector for their in store set up... Link to comment Share on other sites More sharing options...
Scribb|e Posted August 3, 2009 Share Posted August 3, 2009 Well, that timer says that it has an inductive load of 1800W, so it must be a pretty meaty timer. You should be able to run a pair of 600W or a 1000W comfortably using that. It's nothing to do with 'being in the US', though - it's just a simple fact of electronics. Link to comment Share on other sites More sharing options...
Mr Greenhorn09 Posted August 3, 2009 Share Posted August 3, 2009 Well, that timer says that it has an inductive load of 1800W, so it must be a pretty meaty timer. You should be able to run a pair of 600W or a 1000W comfortably using that. It's nothing to do with 'being in the US', though - it's just a simple fact of electronics. Thanks Scribble! Link to comment Share on other sites More sharing options...
scraglor Posted August 4, 2009 Share Posted August 4, 2009 15 Amps, 1800 Watts Inductive * 500 Watts Tungsten * 125 Volts AC, 60 Hz * 1/3 HP doesn't make sense, the tungsten rating is less than the inductive rating? also a 1/3hp motor (inductive load) is only 250Watts 15 x 125 is 1800W so i'd say that's it's resistive rating not it's inductive rating. HID ballasts have large capacitors in them anyway, which makes the inductive rating of timers pretty much irrelevant Link to comment Share on other sites More sharing options...
Mr Greenhorn09 Posted August 4, 2009 Share Posted August 4, 2009 15 Amps, 1800 Watts Inductive* 500 Watts Tungsten * 125 Volts AC, 60 Hz * 1/3 HP doesn't make sense, the tungsten rating is less than the inductive rating? also a 1/3hp motor (inductive load) is only 250Watts 15 x 125 is 1800W so i'd say that's it's resistive rating not it's inductive rating. HID ballasts have large capacitors in them anyway, which makes the inductive rating of timers pretty much irrelevant Thanks Scraglor. You are actually right. I went to the store last night to check this thing out in person and it said the inductive load was only 12 amps, not 15. It seems the store websites are even confusing resistive and inductive. I asked the store electrician if there was anything rated for 15 amp inductive and he suggested the mechanical timers used for street lights...about $55.00... Anyway I bought the thing for $18.00 to use on my 400 watt light. I've read all the fine print on the ballast and it doesn't say anything about the requirements. Hoping this thing doesn't burn my house down... I'm definitely getting burnt out from information overload. Link to comment Share on other sites More sharing options...
Guest cantharis Posted August 5, 2009 Share Posted August 5, 2009 (edited) Why are there so many people trying to justify NOT doing the job properly and using a contactor? My cheapo chinese made timer is rated at a 3.5kW resistive load. However I use a relay rated for a 1.5 horsepower motor inductive load - a little over 1 kW inductive - to switch my 400w HID. It is a 30A ´power relay´ sold by Maplins at 4.54 UKP plugged into a base costing a further 2.73 UKP. Why hazard your safety when it costs so little to do it right? Edited August 5, 2009 by cantharis Link to comment Share on other sites More sharing options...
Farmer C Posted August 5, 2009 Share Posted August 5, 2009 Agreed. £30 from ebay, or knock one up yourself very easily for about a tenner. I followed the instructions on this site, and it works perfectly. Link to comment Share on other sites More sharing options...
Mr Greenhorn09 Posted August 5, 2009 Share Posted August 5, 2009 For me it is pure ignorance. I have read and re read the posts here for contactors and it's something that I just don't understand. For me it has been more confusing because we don't call them contactors in the US. We generally call them electrical relays. If you ask someone at the store for a contactor they will look at you like you have 3 heads. Also the DIY tutorial is done by UK standards and the original post for on OG for Americans is now gone. I've been looking at the already built relays but they require wiring too. Between the complexity of electrical wiring and the cost of the entire system, the entire thing gets pretty overwhelming. I've put out nearly 1,000.00 for my set up and have yet to get compost, nutes, potters, and other things. It seems everytime I think I am nearly finished buying things another 50.00 - 100.00 cost pops up. Link to comment Share on other sites More sharing options...
Scribb|e Posted August 5, 2009 Share Posted August 5, 2009 There's a US member here (sorry, I forget their name), and they were using some big-arse mechanical timer/relay that might have been used for street lighting or something similar - I'm sure they said that they were available for like $30 or so. Link to comment Share on other sites More sharing options...
Mr Greenhorn09 Posted August 5, 2009 Share Posted August 5, 2009 There's a US member here (sorry, I forget their name), and they were using some big-arse mechanical timer/relay that might have been used for street lighting or something similar - I'm sure they said that they were available for like $30 or so. Thanks Scribble. I think you are talking about 'The Yank" haha. He posted a picture of his timer on post 65 of this thread. I can get a mechanical timer just like the one he is talking about for 49.00 that is rated for a 40 amp load. It is basically used for street lights which are obviously HID. Don't know how they are wired.. I just can't believe you gotta go through all of this for a 400 watt light haha. The guy at the grow shop just plugs it right into a surge protector.. The one at the store looks like this: I know you guys are all gung ho over contactors, but in reality your all doing it wrong period. Your starting of using inferrior timers instead of getitng a comercial timer. I must have posted this about 5 times already. If you have the right time clock then you do not need a contactor, if you need a contactor, your using the the wrong clock. Dikki, yoru right to a point but infact you do not need a contactorHere is the one I am using for both of my 250w lights. And seeing is is designed spefically for these type of HID lighting, in fact THIS IS them absolute right way of doing it regardless of what anyone says. It is rated @ 40 amps 120v for the US and I am sure you have somthing equivilent and available to you guys over there. I am not trying to start an argument, but I am sick of people saying that a contactor is the right way when in fact it is not at all. All you have to do is use the right parts, on top of this, I believe this timer cost less then your contactor and cheap timer combined. Link to comment Share on other sites More sharing options...
Guest cantharis Posted August 5, 2009 Share Posted August 5, 2009 (edited) Agreed. £30 from ebay, or knock one up yourself very easily for about a tenner.I followed the instructions on this site, and it works perfectly. Here is mine, using the 30A ´power relay´and base from Maplin. The two pin plug goes into the timer, and just activates the solenoid. The relay contacts switch the LIVE feed, as seen. (Actually, in the continental system both feeds are live.) I have wired mine so that it is ´normally on´ - the light spring in the relay holds the contacts on - when the timer energises the solenoid, I use the more powerful pull of the solenoid to very positively pull the contacts apart, so no chance of any damaging arc as the contacts open. So the solenoid holds the HID and ballast in the OFF position. Edited August 5, 2009 by cantharis Link to comment Share on other sites More sharing options...
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