I am using a Panasonic relay (ALQ105) rated for a resistive load of
10 amps 5A at 250V to drive LED bulbs. These LEDs have capacitive circuits in their ballasts and hence draw high inrush current when switched ON. Steady state current is quite low (less than an amp at 220 Vac).
This inrush current (and possible spark during switching) is causing contact welding in the relay. I cut open one and found the contacts stuck together. A gentle prying with my finger nails separated them together. I couldn't find any black deposits (which I suspected would be there due to sparks). The value of capacitance in the circuit is unknown and different in different cases. As such I am looking for a general method to get rid of this issue. I could think of these three possible ways:
1) Use a series resistor and possibly an inductor to limit the high inrush current - Possible negative effects would be steady state power dissipation in resistor. Also, I am not sure about what values of R and L should I choose.
This looks a better idea as compared to L-R circuit but I am not fully sure of the calculations that I need to do for selecting the correct part.
3) Switching to solid state devices like triacs. Since there won't be any mechanical contacts, there won't be any welding. I am currently using BTB-16-800-BW triac in other applications. (ST BTB16 Triac datasheet)
This has a steady current carrying capacity of 16A which is much more than what my requirement is. It also has a surge current limit of 160 A. However I am not sure whether 160 A is good enough for the load I am dealing with.
Please help me selecting the best feasible solution for this issue.
[Updated relay contact rating to correct value of 5A at 250VAC]