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Old 30-01-18, 01:37 PM   #41
Bravemeister
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There is life!!

Had the set running for about 15 mins last night having replaced the capacitor! Lucien, many thanks for your help!

Now moving on to the relay coil... I'm going to speak to a guy at work who has had motors etc re-wound before and the look in to getting the coil re-wound.

Matt.
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Old 06-02-18, 06:15 PM   #42
Lucien Nunes
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Regarding rewinding the coil of LC, as it is for fairly high voltage DC it will have many turns of fine wire. However, if you can discover exactly what gauge the wire is, by pulling up an outer turn, it is not terribly difficult to rewind. You don't have to count the turns, which is a good thing as is it is probably vacuum-impregnated with varnish and will be impossible to unwind. If you can confirm the resistance of someone else's example, put on more than is required, i.e. by filling the bobbin beyond where the old winding came to, then unwind until you have the correct resistance. You can also corroborate the correct amount of wire by weight, comparing the old winding after cutting it off, with the amount of wire required to achieve the desired resistance. A good soak in Glyptal insulating varnish will protect it reasonably well, in place of vac impregnation.

Before stripping the existing winding, take a careful look at the ends, especially where the wire enters the bobbin. Failures often occur at or near the ends because that is where the wire is stressed, and where soldering flux may have attacked it. I have repaired many seemingly open-circuit coils without rewinding, by picking up the stub left after corrosion had eaten through the exposed tail.
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Old 15-02-18, 08:44 PM   #43
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Hi Lucien,

Many thanks for your response.

I'm looking on the internet to find someone with the same generator set and LC coil and contact them to measure theirs......

I will measure the gauge of wire, and yes, very thin, almost hair like.

I did go about looking at the terminals to see if I could take one wind out and resolder it up, however looking closer some of the varnish has come away and overall isn't looking great.

Measuring the mass of wire taken off is a good idea, though I reckon I'll be doing this as a last resort for trying to resurrect the coil and moving on to an alternative method
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Old 13-03-18, 09:40 PM   #44
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Its been a while....

After a lot of searching and phone calls I have finally got my coil re-wound. I will be collecting it on Friday and getting it hooked up for testing over the weekend!

Its been a long time coming, am pretty excited to see if it will work! I have noticed that before the coil there is another selenium rectifier, is it worth bypassing this and replacing with one of the 1n5408 silicone diodes or test with it and see if it works as is..?

Matt
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Old 14-03-18, 06:12 PM   #45
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Yes, replace LCR with a 1N5408. No point adding any more variables into the equation and all old selenium recs are now likely to be variables. We know it rectifies - early in the testing we found the correct voltage present at its cathode - but it might be high-resistance which will make LC sluggish. Leave the selenium in place, solder one end of the diode onto it and move the lead from the tag at the other end of the selenium onto the diode.

After reassembling LC, ensure by visual / meter checks that the contacts have not become deranged and in particular, that LC1 and LC4 operate correctly. As mentioned above, if these are both closed at once, the detection rectifier could suffer.
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Old 26-03-18, 08:55 PM   #46
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It lives!!!!!

Coil works spot on! Shout-out to Bradford Armature winding company who re-wound it!

Lucien, many thanks for your assistance over the past few weeks/months!

Now to make it a nice trolley and wire it up to my workshop ready for backup power, or when I just fancy making a noise!

Thanks again,

Matt
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Old 26-03-18, 11:17 PM   #47
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Quote:
Originally Posted by Bravemeister View Post
It lives!!!!!

Coil works spot on! Shout-out to Bradford Armature winding company who re-wound it!

Lucien, many thanks for your assistance over the past few weeks/months!

Now to make it a nice trolley and wire it up to my workshop ready for backup power, or when I just fancy making a noise!

Thanks again,

Matt
Fantastic work!
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Old 26-03-18, 11:52 PM   #48
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Excellent. It can be a long fiddly process when you start out with multiple faults and unknowns, but with tenacity most electromechanical things can be fixed. It's worth making sure that LC is operating and releasing at a sensible voltage - put a meter across the incoming 230V AC from the genny and post your findings.
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