Mosaic
Well-Known Member
Hi all:
I have an app. that runs pulsed power thru an automotive 12VDC coil relay when it is not switching (64mS debounce buffer). The relay is rated @ 80A and contains a single SPDT contactor. I have seen SPDT contact temps up to 100C.
I am considering a 100A relay that carries a pair of contactors as well as paralleling the existing 80A relay.
The pulsed currents average about 7.2A max, but they can approach 800 A with a very low DC%, which is why the contact is heating.
Heat seems to ramp 15°C per RMS ampere.
After some months service, the SPDT contact starts to 'stick' sometimes. Cleaning the contact solves the problem for a while.
Paralleling relays is not normally suggested, but with no load switching and the positive thermal coeff. of the contacts, I see an opportunity for load sharing.
Any thoughts?
I have an app. that runs pulsed power thru an automotive 12VDC coil relay when it is not switching (64mS debounce buffer). The relay is rated @ 80A and contains a single SPDT contactor. I have seen SPDT contact temps up to 100C.
I am considering a 100A relay that carries a pair of contactors as well as paralleling the existing 80A relay.
The pulsed currents average about 7.2A max, but they can approach 800 A with a very low DC%, which is why the contact is heating.
Heat seems to ramp 15°C per RMS ampere.
After some months service, the SPDT contact starts to 'stick' sometimes. Cleaning the contact solves the problem for a while.
Paralleling relays is not normally suggested, but with no load switching and the positive thermal coeff. of the contacts, I see an opportunity for load sharing.
Any thoughts?