scraglor Posted August 13, 2012 Share Posted August 13, 2012 laphroaig, yes, a motor does act as a generator just from the momentum of it spinning, due to the rotor still being magnetised from when it was running, the magnetism creates voltage (and if a load is connected to the terminals - current) which in turn remagnetises the rotor. if you drive a motor with an external source, it creates power but i expect you initial theory is a more likely culprit, you need to interlock your switching circuit if this is the case, so one switch cannot close until the other is open, can't say how or why you're getting the problem you are without knowing/seeing the circuit/fault myself of course. as for the burnt terminals, usually this is down to a bad connection and/or underated cable or terminals (unlikely for a fan as the amperage is so small, but again, need more details and photos 1 Link to comment Share on other sites More sharing options...
Peter Petrelli Posted August 13, 2012 Share Posted August 13, 2012 Hi guys, and thanks for the help. Lap haven't been on here for a bit so wasn't aware they'd made changed to the pic upload procedure cheers for pointing that out....The variac in question is the one I built from scratch using 2 x ravi-stats, not the one I initially considered adapting. Scrglor I will get the pictures sorted by tomorrow eve and some good one's of what I've done wiring wise. Although the link I posted is pretty much how it still is just took your advice from my last thread (also in last post) to get the variac's to work as intended, i.e: increase power on variac and fan speeds up as apposed to slowing down. Pics and more details to follow Link to comment Share on other sites More sharing options...
Peter Petrelli Posted August 15, 2012 Share Posted August 15, 2012 Ok sorry for not uploading the pic yesterday but I quit after trying to locate 'my gallery' for over 30 mins........ What a total feckin pita that new image upload procedure is, I can see how it will be ok in the long run... But feck me I had to spend 20 mins searching threads that have the wrong bloody info in em to get to the correct procedure ffs! [Rant Off] ! OK here's the burn that I was talking about The wiring is exactly the same as it was in the pic I posted before except for the changes I speak of in my last post. I will get another pic of wiring for you guy this eve though and post up tomorrow now I got my head around the gallery function. Link to comment Share on other sites More sharing options...
Laphroaig Posted August 15, 2012 Share Posted August 15, 2012 (edited) Don't suppose you could do a few clearer ones of the wiring inside, your terminals etc. Dunno about everyone else but hard to tell what's going on from what we have already, plus seeing the wiring inside and state of the connections gives a big clue to exactly where the problem is. The it's exactly like that, but I changed it, doesn't work, we need lots of new pictures of the inside . So you can practice using your new gallery. Peace Edited August 15, 2012 by Laphroaig 1 Link to comment Share on other sites More sharing options...
scraglor Posted August 15, 2012 Share Posted August 15, 2012 (edited) need to know EXACTLY how it's wired, is that 1.5mm wire? that looks like overload damage unless the actual terminals are all burnt up too... in which case the damage will likely be from the heat originating at the terminals travelling up the wire? very odd, talking circa 25A+ to do that kind of damage if it's actual overload damage, as i take it there's no way that's come from an external heat source??? Edited August 15, 2012 by scraglor Link to comment Share on other sites More sharing options...
Peter Petrelli Posted August 15, 2012 Share Posted August 15, 2012 I will get those pictures of the wiring up tomorrow at the latest! Need to get it sorted asap as my TD silent absolutely hates my SMS fan controller! Link to comment Share on other sites More sharing options...
Peter Petrelli Posted August 16, 2012 Share Posted August 16, 2012 Right got these pics sorted, but I got to be honest I wired everything up based on instructions I read online and can't really recall exactly what went where. Hopefully you technically minded folk will be able to work it out from the pics. Here's a diagram of what I did though: http://www.uk420.com/boards/index.php?app=core&module=attach§ion=attach&attach_rel_module=post&attach_id=531704 and here's the pics of how it's wired up now (note there is an earth coloured cable leading from the variac into the box with red tape on, this is not an earth but I ran out of wire. All wiring inside box is 1.5mm rated for far over the amount being drawn by the fan etc). Link to comment Share on other sites More sharing options...
Peter Petrelli Posted August 16, 2012 Share Posted August 16, 2012 More: Really appreciate the help and patience guys Link to comment Share on other sites More sharing options...
scraglor Posted August 16, 2012 Share Posted August 16, 2012 are the cables hot to the touch? leave the thing running for a good 10 minutes (under observation of course) and see if any of the cores on the burnt cables are hot to the touch.... really you need to get a clamp meter and measure the current going through each of those wires in the burnt cables i see one fuse there, which i guess is the main feed in, really you should move that to the output of one of the transformers, and wire in another one for the second transformer output (the main feed is fused in the plug top) Link to comment Share on other sites More sharing options...
Peter Petrelli Posted August 16, 2012 Share Posted August 16, 2012 I'll test it now mate, a clamp meter will need to be ordered as I don't see them on bnq or wickes websites. I have a multi meter but I guess that's no good for the test you speak of. I'll also move the fuse from it's current position to where you have suggested and run another as advised also. Give me 30 mins or so and I'll have that sorted, then post back with the results. Cheers Link to comment Share on other sites More sharing options...
scraglor Posted August 16, 2012 Share Posted August 16, 2012 it's just to measure the current, you can do it with a multi meter, but you'll need to wire the meter in series with each core you test with some chocblock or something (and remember to swap the test leads into the 10A current terminals on the meter) just want to see how much current is going through each core when it's running. Link to comment Share on other sites More sharing options...
Peter Petrelli Posted August 16, 2012 Share Posted August 16, 2012 OK, so the local Maplins doesn't have the fuse holder in stock so will have to leave that until later/ tomorrow. I've had the variac running now for about 30mins and none of the cables are hot to touch. I think I'll pick up socket tester to make sure the socket I used before isn't playing up at all. Think I'll justpick up the cable tester as it sounds like a useful tool to have lying around. Link to comment Share on other sites More sharing options...
scraglor Posted August 16, 2012 Share Posted August 16, 2012 ok, maplins do a clamp meter fairly cheap i believe...... so you've had the fan running, does it run two fans or one fan? bit confused.... but either way, keep it running, and have it switch speeds or do whatever it does... if the cables aren't even getting hot or warm to the touch (and feel the actual individual cores of wire, then i'd say the discolouration is due to some external heat source, maybe cables got too close to the lamp at some point?? Link to comment Share on other sites More sharing options...
Peter Petrelli Posted August 16, 2012 Share Posted August 16, 2012 (edited) Hi mate, I managed to grab a fuse holder so have that sorted but left my wallet indoors, doh! So I'll grab the clamp meter tomorrow early. The unit has been running since I last posted switched once or twice between variacs and cables still not heated up. The variacs run one fan currently and did for the last grow, but I may add another intake fan if it gets to hot in there as I will be using vertically orientated bulbs now (2x 600). On the last grow it just cycled between running @ 45% and 60% when the temp reached over 27C. The individual wires within cable are not heating up either and the variac unit has never been inside the tent. So definitely no external heat source to blame. Edited August 16, 2012 by Peter Petrelli Link to comment Share on other sites More sharing options...
scraglor Posted August 16, 2012 Share Posted August 16, 2012 cant really think of anything else, the rotor of the fan could jam up, but even that shouldnt pull enough to overload 1.5mm cable, and the fan wouldve fried. so dunno mate? Link to comment Share on other sites More sharing options...
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