Hi Glenn,
That was a handy post for us lazy guys. I normally just order what I need, but thanks to you I have a list I can lose and cuss about!
Anyway, a very good compilation. It still comes down to reading what is printed on the side of the casing of the relay.
If I may give some guidelines as to when a relay requires replacement and not....
If the contacts are pitted, or have been cleaned with abrasives - Replace!
If the contacts are simply tarnished (oxidized), they can be cleaned with any contact cleaned on a business card. After that, the cleaner must be washed out with a non-residue cleaner. I've had cleaned relays lasting as long as replaced ones in equipment I own. This is very useful if you come up against an odd ball relay, or you happen to be out of relays. Just remember that the plating is very thin. If the plating is damaged at all, the relay must be replaced.
Cleaning a relay does not take a long time to do. I guess the mindset is that if you have the old one out, you may as well install a new one. I have to admit that it is faster to install a new relay.
-Chris
That was a handy post for us lazy guys. I normally just order what I need, but thanks to you I have a list I can lose and cuss about!
Anyway, a very good compilation. It still comes down to reading what is printed on the side of the casing of the relay.
If I may give some guidelines as to when a relay requires replacement and not....
If the contacts are pitted, or have been cleaned with abrasives - Replace!
If the contacts are simply tarnished (oxidized), they can be cleaned with any contact cleaned on a business card. After that, the cleaner must be washed out with a non-residue cleaner. I've had cleaned relays lasting as long as replaced ones in equipment I own. This is very useful if you come up against an odd ball relay, or you happen to be out of relays. Just remember that the plating is very thin. If the plating is damaged at all, the relay must be replaced.
Cleaning a relay does not take a long time to do. I guess the mindset is that if you have the old one out, you may as well install a new one. I have to admit that it is faster to install a new relay.
-Chris
Hi Nigel,
I refuse to waste money and have a great deal of experience cleaning relay contacts. Besides, some of the odd signal relays are not available any more. Fujitsu is a prime offender.
However ....
As long as the plating on the contacts are not damaged and just oxidized, they can be cleaned properly and last in excess of 10 years without any trouble. This depends on environmental factors which would cause a new one to fail also.
Again, contacts can be properly cleaned. If this is done, they will continue to work for years to come. Any damage to the plating on the contacts will disqualify the relay for cleaning. This includes pitting (like on speaker relays many times), scratches to base metal (got to love those burnishing tools!) or sandpaper (that removes the plating just like the previous example).
Therefore, if you clean the relay, rather than "Bodging" it, no problem.
I have cleaned relays on customer equipment after informing them of my intentions and reasons. Any contact damage requires a new relay unless they are simply not available. I'll bet that in desperate cases, you could re-plate the contacts. Just thought of that.
-Chris
Simple.
I refuse to waste money and have a great deal of experience cleaning relay contacts. Besides, some of the odd signal relays are not available any more. Fujitsu is a prime offender.
That is very true, no arguments from me on that.
However ....
As long as the plating on the contacts are not damaged and just oxidized, they can be cleaned properly and last in excess of 10 years without any trouble. This depends on environmental factors which would cause a new one to fail also.
Again, contacts can be properly cleaned. If this is done, they will continue to work for years to come. Any damage to the plating on the contacts will disqualify the relay for cleaning. This includes pitting (like on speaker relays many times), scratches to base metal (got to love those burnishing tools!) or sandpaper (that removes the plating just like the previous example).
Therefore, if you clean the relay, rather than "Bodging" it, no problem.
I have cleaned relays on customer equipment after informing them of my intentions and reasons. Any contact damage requires a new relay unless they are simply not available. I'll bet that in desperate cases, you could re-plate the contacts. Just thought of that.
-Chris
hi all i considered cleaning the relay but as i'm changing the big caps and the other electrolytics on the other boards i decided to buy new ones. i plan to change the diode next to the relay i was wondering if any of you kind gentlemen could tell me a modern equivalent for it. it is diode D601. thank you for your help
That will be a suppression/protection diode and a 1N4004 will be more than ample.
I use a later type of carbon tetrachloride, then CRC 2-26 as spray, reduces arcing.
To supress arcing on mains relays, I have used Metal Oxide Varistors, they increase contactor life by about 3 times, as the arc at the time of making and breaking contacts is absorbed.
For lower voltages, maybe a R-C in series asross the contacts, 0.1 uF non polar and 47 or 100 ohms would work to absorb the arc.
How that would affect the signal is to be seen.
To supress arcing on mains relays, I have used Metal Oxide Varistors, they increase contactor life by about 3 times, as the arc at the time of making and breaking contacts is absorbed.
For lower voltages, maybe a R-C in series asross the contacts, 0.1 uF non polar and 47 or 100 ohms would work to absorb the arc.
How that would affect the signal is to be seen.
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