Ignition transformer insulation (Navien)

mikemac52

new replacement ignition transformer on a Navien NHB does not have the fibrous insulation material in the boots.
The supply house checked and none of their stock on hand has it.

Can find no info on it.
Is it no longer considered necessary?

The original stuff is rather friable and only able to reuse enough for half of one boot.

Thanks for your time

109A_5

Pictures may help. May just be a production change. Especially if the old stuff does not hold up well.

mikemac52

Lol, taking it out again it was crushed and now makes it look like a piece of lint .

Previously it was not flat and filled the cavity in the boot around the electrode.

I just sort of shoved the pieces back in for the photo. Imagine fluffy lightness evenly spread out in the insulation boot.🙃

all this compression I think it no longer will work as designed. 🤔

HVACNUT

Item 19, Flame Rod, shows it comes with the gasket. They should supply 10 with every Flame Rod because they fall apart if you breathe on them.

EdTheHeaterMan

 I have never seen anything like that on the inside of an ignition cable connection.   Is that really an original equipment part (or substance)?   I would not use that stuff in making a connection to the ignition system.  The innards of that wire and connector boot should make a metal to metal connection without any fibrous fungus inside it.   That is just my opinion.

mikemac52

Hi @HVACNUT

Absolutely right on the flame rod gaskets, hateum. I'm asking about item 24 though, the insulation boot on the ignition transformer. Any ideas?

Hi @EdTheHeaterMan

Yes, original transformer being replaced. 6 years old about and had that material inside which mostly crumbled when removing the old transformer. Yes, the contact inside makes quite nice contact with the electrodes of the flame rod. The material seems to have been a dielectric.

And after fooling around with neon transformers for a long time, let me tell you those big rubber boots you put over the connection don't guarantee much in protection from 15kv. So, the addition of the fibrous material makes sense to me but perhaps as @109A_5 said, it was a production change.

If I could find the material, it would be nice to use regardless. (I hate arcs)

Thanks for your (all) help.

109A_5

I've worked on a variety of equipment that has high voltage, up to 160,000 VDC. I have never seen a high voltage connection with some intentional debris like that in it. Depending on the application they are often an 'air tight' connection, like the rubber boot on the spark plug to wire connection on a gasoline engine. If I had to guess that is some kind of packing material that was never cleaned away and discarded.

109A_5

If the electrical connection is secure and properly insulated from the rest of the world there won't be any sparks in undesired places.

mikemac52

@109A_5 What in the heck were you playing with 160kv dc for. Are you crazy! 😱

I shouldn't have shoved the pieces back in for the photo, gives the wrong idea. When it was untouched, it was purposeful and tidy looking.

I am truly curious though what you were playing with. The high voltage stuff. (I'm an elec-chicken first. Just under 1Kv stuff)

109A_5

X-Ray machine for industrial parts inspection, many go higher than that.

Not seeing an item 24.

No extra gasket in this illustration.

109A_5

At that voltage and the proper ignition rod spark gap if every thing is kept clean it may not be much of an issue.

Still if the present boot leaves an air gap that you don't like maybe could you add some appropriately sized silicone rubber 'O' rings to seal the gap ? Or thin wall silicone tubing ?

mattmia2

if you want something to pack in there you could use this which is made for the purpose, mostly used on crt anode wiring:

https://www.gcelectronics.com/product/10-8880

(high voltage putty)

you could also use dielectric grease if the gap is small.

SuperTech

I wouldn't worry about it. Unfortunately I work on Naviens all the time. I throw that stuff away when it falls apart. The heat exchanger failing will certainly be a problem before anything happens as a result of that fluffy fibrous junk missing.