Repairing OT secondary wires

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ViperDoc
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Repairing OT secondary wires

Post by ViperDoc »

I just unboxed an OT for another build and I noticed the secondary wires were crimped and damaged by the weight of the OT at some point during shipment.

Image

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The business I bought them from is willing to send me a replacement. However, I thought I could just cut out the crimp on each secondary wire and splice them back together. I won't have luxurious space underneath the board, perhaps 1/2 inch.

Methods of choice?

1) Strip, solder and heat shrink,
2) wire nuts,
3) Posi-Lock connectors,
4) butt splice connectors...

...or would you just send it back?

Thanks.
Just plug it in, man.
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statorvane
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Re: Repairing OT secondary wires

Post by statorvane »

Your choice but if the supplier will replace it I'd send it back.
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Re: Repairing OT secondary wires

Post by Stevem »

Strip & solder.
Then double shrink, one short length to cover the striped portion and then a longer one to enclose that.
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thetragichero
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Re: Repairing OT secondary wires

Post by thetragichero »

i would definitely get it replaced as they'll hopefully package it better
but the strip and heat shrink is the way to go in cases where a replacement is not going to happen
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didit
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Re: Repairing OT secondary wires

Post by didit »

Hello -

Depending on layout positionings it is possible, maybe even probable, what remains is enough? Or patiently await the offered replacement.

Best .. Ian
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Phil_S
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Re: Repairing OT secondary wires

Post by Phil_S »

Send it back is the best and first option as other have said. IMO, the seller is responsible for packing to avoid shipping damage. It looks like a serious shipping bruise because it was floating inside the box. Really, it just takes a bit of wadded up brown paper or foam sheet goods to do a decent packing job.

If a replacement isn't going to happen, then a repair is certainly possible. I can't really tell from the pictures if the problem is just the insulation getting messed up or if the stranded wire is also broken. If it is just the insulation, I would probably trim the insulation humps (use a razor blade, side cutters, or small scissors) without nicking the actual wire, and cover with heat shrink. Maybe I'd use two layers of heat shrink if I thought it was a bit too thin. If some of the wire is broken, you really should clip, splice, and cover with heat shrink. I've done this. It's not a big deal.

FWIW, I have found the Western Union splice (the gold standard) to be too bulky and stiff after soldering. I don't believe the WU splice was meant to be soldered and I'm not comfortable just covering with heat shrink. Instead, I will twist and solder. Twist can be done with shorter wire length than a WU splice. Then cover with heat shrink. This will leave it uncovered at the base. The solution is to bend it next to the insulated lead and then heat shrink again so the splice is parallel to the lead. I hope that is clear. Then again, maybe you can do a better WU splice than I can or you are willing to forgo the solder.

There is always the NASA splice:
https://www.youtube.com/watch?v=O-ymw7d ... 1g9XgCoAEC

Good luck.
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drew
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Re: Repairing OT secondary wires

Post by drew »

Marine grade heat shrink butt connectors would be another option.
wpaulvogel
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Re: Repairing OT secondary wires

Post by wpaulvogel »

Just me but I’m going to remove the four bell cover screws and make the repair splice inside. I strip back 1/4 inch of each wire, tin both well and lap them together. It’s a secondary wire so it not going to produce 60 volts so high dielectric isn’t necessarily. A single heat shrink is more than adequate. Primary wire see’s high voltage and needs more dielectric protection.
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ViperDoc
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Re: Repairing OT secondary wires

Post by ViperDoc »

All comments are much appreciated, guys. Thank you.
wpaulvogel wrote: Sun May 02, 2021 11:51 pm Just me but I’m going to remove the four bell cover screws and make the repair splice inside. I strip back 1/4 inch of each wire, tin both well and lap them together. It’s a secondary wire so it not going to produce 60 volts so high dielectric isn’t necessarily. A single heat shrink is more than adequate. Primary wire see’s high voltage and needs more dielectric protection.
I popped the secondary bell off after prying a wee bit. Was hoping to find solder lugs underneath for a way easy repair, but no luck. I'm uncomfortable doing any more. These transformers are painted with some kind of shellac or something. Is it necessary to re-"seal" the bell/core joint or just tighten it back up?

Thanks.
Just plug it in, man.
thetragichero
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Re: Repairing OT secondary wires

Post by thetragichero »

wpaulvogel wrote: Sun May 02, 2021 11:51 pm Just me but I’m going to remove the four bell cover screws and make the repair splice inside. I strip back 1/4 inch of each wire, tin both well and lap them together. It’s a secondary wire so it not going to produce 60 volts so high dielectric isn’t necessarily. A single heat shrink is more than adequate. Primary wire see’s high voltage and needs more dielectric protection.
i have done it this way on a used transformer that somebody cut the leads leaving only an inch or two of wire. in my opinion this way looks the most professional

but i would push HARD for a replacement (not opening the bell covers just yet). depending if you've purchased on a marketplace as long as you haven't attempted to alter it since in your possession you should have absolutely no issue getting one. if it's directly from a merchant, you might have to be annoying (if no joy via email, i find posting an image on their social media of the condition received should elicit a response)
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ViperDoc
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Re: Repairing OT secondary wires

Post by ViperDoc »

Advice much appreciated. I haven't altered a thing, I just popped the bell to look underneath. The merchant offered to replace it at my discretion, which I both respect and took him up on. We'll see how long it takes. Honestly, it's tempting to fix it but I don't like the idea of cut and soldered leads on the OT. I know it's soldered inside primarily, but how many of those connections do I need? My shoulder devil points out all the turrets I have on the build, and my shoulder angel wants to bless the merchant for being so cool about it. So a new one is on the way, hopefully soon.
Just plug it in, man.
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Re: Repairing OT secondary wires

Post by wpaulvogel »

I understand if you don’t want to splice the wires. I’ll bet that it gets spliced and re sold though. I just figured it would save time. Just install the bell cover and tighten, the varnish is for the core windings and the laminations.
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Re: Repairing OT secondary wires

Post by martin manning »

ViperDoc wrote: Mon May 03, 2021 1:53 amI popped the secondary bell off after prying a wee bit. Was hoping to find solder lugs underneath for a way easy repair, but no luck. I'm uncomfortable doing any more. These transformers are painted with some kind of shellac or something. Is it necessary to re-"seal" the bell/core joint or just tighten it back up?
The sticky stuff is commonly called varnish. The core and coils are saturated with it after assembly, and then oven cured. It prevents absorption of moisture and movement of the coils. If a transformer becomes too hot in operation at some point, this is the stuff that drips out.
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