Both my lights 1000 watt MH and 1000 watt HPS run at 9.5 amps@120v each. No way I can run both on a 20 amp breaker. I have a kill-a-watt monitor & detector and have seen it spike to 13 amps. If you use 600 watt lights you can run 2 per 20 amp line otherwise only 1 1000 watt per line and still...