electricpete
Electrical
- May 4, 2001
- 16,774
It's a strange request I know.
We are monitoring a hot crimped lug on a 16 awg wire in a 125vdc control circuit. I don't know the current ;-(
The crimp has a temperature rise approximatley 8C above surroundings. The other identical crimped connections in the cabinet have on the order 1C rise, even though they carry comparable load. i.e. the crimp in question is line side of fuse, carries daisy chain current to line side of several other fuses. Points "upstream" and downstream in the daisy chain are 1C.
This has been monitored for a month. There was a period when the delta-T dropped to ~1C for a few days and then jumped up. I believe there was an increased current prior to this period which some theorize may have provided a mechanism to temporarily reduce the resistance.
By the way, failure of this connection has severe consequences and actions to effect repair are risky as well.
Question 1 - How severe would you estimate this condition?
Question 2 - In discussing this item we have been asked to provide examples of lugs which have failed due to overheating. Preferably ones which were being monitored so there might be some idea of how the temperature rise behaved during the time before failure. Preferably control circuit lug crimped connection.
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Eng-tips forums: The best place on the web for engineering discussions.
We are monitoring a hot crimped lug on a 16 awg wire in a 125vdc control circuit. I don't know the current ;-(
The crimp has a temperature rise approximatley 8C above surroundings. The other identical crimped connections in the cabinet have on the order 1C rise, even though they carry comparable load. i.e. the crimp in question is line side of fuse, carries daisy chain current to line side of several other fuses. Points "upstream" and downstream in the daisy chain are 1C.
This has been monitored for a month. There was a period when the delta-T dropped to ~1C for a few days and then jumped up. I believe there was an increased current prior to this period which some theorize may have provided a mechanism to temporarily reduce the resistance.
By the way, failure of this connection has severe consequences and actions to effect repair are risky as well.
Question 1 - How severe would you estimate this condition?
Question 2 - In discussing this item we have been asked to provide examples of lugs which have failed due to overheating. Preferably ones which were being monitored so there might be some idea of how the temperature rise behaved during the time before failure. Preferably control circuit lug crimped connection.
=====================================
Eng-tips forums: The best place on the web for engineering discussions.
