What is the thick yellow grease inside the PNP switch?

Post by **jreed** » 18 Jan 2023, 18:46

I opened up my old PNP switch and I’m wondering what type of grease is the yellow grease slathered all over the metal contacts?

: Yellow grease inside old PNP safety switch; DC9C7B83-CB47-4624-9B90-D8B1DDAF90CC.jpeg (692.93 KiB) Viewed 637 times

Post by **scot850** » 18 Jan 2023, 18:52

I am not sure, but I would suggest it has to be a non-conductive grease like di-electric grease.

I'm curious how badly worn the 3 replaceable pins are that you can get in the repair kit? Top one looks worn but the other 2 not too bad. Maybe a good clean out of the grease, a light clean with very fine sandpaper on the areas where there is carbon residue, and then new grease it may be good to go again.

Neil.

454cid · Post by **454cid** » 18 Jan 2023, 18:54

Weird that it's that bright of a yellow. I was expecting more of a tan.

Post by **abscate** » 18 Jan 2023, 23:49

Probably just oxidized lithium grease ?

Post by **volvolugnut** » 19 Jan 2023, 08:33

Frenches mustard?

volvolugnutr

Post by **jreed** » 19 Jan 2023, 09:43

I took some higher magnification photographs of the copper contactors.
They have some black tarnish and some wear. The first photograph is the contactor seen from the side. The contact surface is at the top.
The second photograph shows all three contactors side-by-side looking down at the contact surfaces
The blue arrow in the image below is pointing to the largest amount of wear I could see.

: F87A034C-2CDF-414C-8031-101D47AF59A7.jpeg (920.36 KiB) Viewed 587 times

There is some black tarnish on the contact surface of the middle and bottom contactors.

: 4AB35303-A871-4544-8A92-C122730E490C.jpeg (953.49 KiB) Viewed 587 times

For scale, the bars on the steel ruler at the bottom of the photographs are 1 mm apart.

454cid · Post by **454cid** » 19 Jan 2023, 09:49

Oh wow, great pictures!

Post by **scot850** » 19 Jan 2023, 14:19

Great photos and thanks for those. It looks like that the repair kit just replaces those worn contacts. If that is all that wears on these, then the repair kit seems like a good way to fix these worn units with no new PnP's being available.

Neil.

Post by **erikv11** » 19 Jan 2023, 16:23

Those contacts don't look bad at all, seem pretty even though I don't see them all in profile at the same time.

Years ago i opened one up, filed all three contacts flat and to same size, then put it back together. They were very different in size when I got to them. The PNP had been acting up, that fixed it.