ligtening application

hi,

we are using moc3021 in lightening application as zero cross detector.
intitially the series resistor is getting burnt with 1/4w. if resistor is increased triac on delay is observed, so with lower value and 1/2w resistor is not getting burnt but moc is getting failed when dimming of light in long run.(not getting failed immediately). i think moc3081 can be used instead moc3021. kindly help in this regard.and also pls sujject the circuit.

The MOC3081 turns on and off at zero crossings. The MOC3021 doesn't do any zero cross detection.

But anyway, "lighting application" is not well defined. Dimmer? Tungsten? Dimmable CFL's?

Snippet of circuit?