Hey Guys,
After a looooong absence from the keyboard, I have finally got something more in line to post... Okay, not a Lister(oid) type post, but at least, not like my more recent ramblings, something to do with diesel engines and gensets....
I finally (after I guess about 3 years) got down to rebuilding my DEK5000 auto-start silent runner diesel genset. Uncle Dek got a major belting by a ground lightning strike quite a while back - It took out the alternator, some of the switching hardware and generally made him quite grumpy and useless!!
This past weekend I wheeled him out to the workshop and did a full post-mortem on him... (bear in mind that he went to two local emporiums for refurbishment as was required by insurance, and both of them pronounced him DOA and not worth the mixed weight of scrap metal... Which of course prompted me to build TM1 a good while ago.)
Well, what an interesting weekend it was... Yes the alternator as a whole was pretty knackered, but the windings are good, no shorts to earth or leakage noted whatsoever - the problem with it (its a brushless unit) is that one of the diodes on the armature is a bit leaky and breaking down - full current is not a possibility with this going on. The second problem is that the capacitor on the exciter winding is really crappy and leaky electrically too - This causes slow energizing of the main fields etc and lack of energizing altogether if the revs drop slightly below the 50hz mark.... Both very easy problems to sort out... But hey, in for a penny... more on this later....
As to the switching hardware that got blown out....Well, Uncle Dek is not exactly standard, one of the first things to get tossed out and replaced with something decent was the crappy DPDT switch-over relay that auto switches between Mains and Gen when he gets fired up... The original shitty relay was replaced with 2x well over-rated Omron contactors on a din rail behind the front fascia.... One contact was burned out on one of them so it required moving the wires to the spare contact (3 phase contactor of which only 2 sets of contacts are used on single phase) and all is well.... While I was at it, I installed a hour/watt/amp/frequency/volt meter through the fascia so I can tell what is happening at a glance.... All good so on to the next niggly bit....
The exhaust/tailpipe was touching against and vibrating the back cover, so I took a look at that with the 10t press and got that re-aligned (Thanks mister fetch and carry courier for bending it)... An exhaust leak was fixed and sorted.... Do those little hexagonal things on the exhaust studs really have to be tightened?
On to the other side of the unit.... Hmmm....that silly little square box with thick cables bolted to it looks way too small for comfort...Extend the tray and put a smallish car battery in, a little Vaseline and it fits/slips in quite easily... Oh look, there is space on the door for a couple of female "banana sockets"... lets stick them in while we are at it so the battery can be charged and topped off without opening the thing up... Am I the only twit that has this problem? .... Aaaaah, while I am at it, and the drain is accessible, lets throw out the sump gunk and stick in some nice new syrup....done!!
Right....now that poor old alternator, what to be done here? ...(Of course, by this stage, I have confirmed that everything else, ie the niggly bits, are all in operation, engine starts and runs as well as holds revs stably )... Lo and behold, lying under my bench is an old Wally-Mart alternator that I converted to belt drive a year or 3 ago by employing a bit of band-sawery and Lathery and removed the suck-squeeze-bang-blow pieces.... I wonder if it will fit? Sure as nuts, it strips the same, bolts the same, tapers the same onto the crankshaft.... only difference is that this bugger is from a 6.5kva petrol and it has an AVR, and its brushed, and it only has one,not two 14vAc windings for internal charging/external 13.8 supply... Stuffit, close enough, in it goes!!
Well, after a good dose of genset proctology - These silent runners need a degree in plumbing to get the ducting on/off/not rattling, I got the "new alt" in and spinning - Set voltage, set frequency, load test....all ok!
A good bit of workshop social with the mates popping in and out (Naturally sporting a carry in of a couple of cold ones, they were not turned away I might add, the weather was around 38C and 95% RH...) Uncle Dek was pampered, spruced, fueled and carried back to his place of residence after a good few hours of testing...
The only thing left to do, should I decide I want to that is, is to put a fascia changeover switch in to select internal/external DC charging....Buggrit, that can wait till another day.....
I fell into the shower last night only too glad for a forthcoming restful Monday at work!!
Keep it spinning...
Cheers
Ed
PS- Guys, sorry I haven't responded directly to any of your comments and writings of late, life has just been so much fun out here in the real world, I have been a bit remiss!!