PLUS+1 User Forum

PLUS+1 Hardware => I/O Modules => Topic started by: Marbek_Elektronik on December 01, 2019, 08:51:22 PM

Title: Using no gold plated contacts instead of original gold plated contacts
Post by: Marbek_Elektronik on December 01, 2019, 08:51:22 PM

Hi,
I have ordered Deutsch gold plated female contacts for Danfoss Controllers.
But I get non plated contacts.

What do you think: Is this a risk to use without gold plated contacts?
I think yes. If there are very low currents and after a few years it might be a problem.

Has anyone experience with this? What says danfoss?

Title: Re: Using no gold plated contacts instead of original gold plated contacts
Post by: SJ Industries on December 02, 2019, 04:32:35 AM

I use gold plated when ever I can, that said after many years of breakdowns on mine sites i can say that 90% of electrical dramas will be the wire itself not the contact between pins. Non tinned wire is terrible. Assembly is key, people not putting the blanking plugs in is a killer. also corrosion x sold by snapon over here is the awesome, a little squirt of that keeps moisture out and the seals in good cond. I dont rate dialectric grease.

So after all that, if your wire is good quality then non plated pins when nothing else is available should be fine.

Title: Re: Using no gold plated contacts instead of original gold plated contacts
Post by: FluidPowerTom on December 02, 2019, 05:42:03 PM

I've made extensive usage of the non-gold contacts without issue.  The only time that I've insisted on the gold contacts is for a very, very long CAN bus.

Title: Re: Using no gold plated contacts instead of original gold plated contacts
Post by: oiltronic on December 03, 2019, 08:55:28 PM

Same as SJ & Tom.  Oldest machine still in service has been open to the damp weather for over 8 years without a single pin-corrosion problem.  Sealing plugs and tinned wire are much more important, in my opinion.

Title: Re: Using no gold plated contacts instead of original gold plated contacts
Post by: Nilla on January 13, 2020, 09:02:42 AM

Hi guys!

We would recommend gold plated contacts.

The main reason is for our input pins. The inputs have a high resistance and that makes for a low wetting current, so any corrosion/oxidation could cause issues over time.

Best regards
Nilla
PLUS+1 Helpdesk team

Title: Re: Using no gold plated contacts instead of original gold plated contacts
Post by: oiltronic on January 13, 2020, 04:16:38 PM

I don't understand how even a worst-case few ohms of resistance from corrosion would make a difference to a low-current, high-impedance input.  Without doing the math, I could imagine problems with CAN or high-current outputs, but not inputs.  Maybe with high-speed frequency inputs.  Could someone explain the issue from an electronics circuitry perspective?  How much additional impedance would an aged tin-plated Deutsch pin introduce to the circuit?

Title: Re: Using no gold plated contacts instead of original gold plated contacts
Post by: G30RG3 on January 14, 2020, 09:35:22 AM

This is a Physical thing:  Whetting is caused by a sort of "surface tension" between contact points.
https://en.wikipedia.org/wiki/Wetting_current

Title: Re: Using no gold plated contacts instead of original gold plated contacts
Post by: oiltronic on January 14, 2020, 03:47:17 PM

I didn't know that a minimum current to "break through"an oxidation layer applied to contacts already in place.  I always thought of wetting current in terms of relay contacts that develop a small corrosion layer when apart then come straight together without any sliding or scraping like a connector pin. 

The Deutsch Common Contact System Technical Manual does not specify a minimum current, but does state:

Quote

Gold plating is available for dry circuit applications

Unfortunately I could not find an industry-standard definition of "dry" (or wet) circuits, with manufacturer current levels ranging from 0.5 to 100mA.  Since Danfoss says their high-impedance inputs are dry by Deutsch standards, I'll switch to using gold plated contacts when appropriate.