like i said i have purchased a Sentinel GPS HPLC-8T High Power Lighting Controller 8 Outlet with Integrated Timer
Curious as to why you believe that the Sentinel GPS HPLC-8T has "built in circuit breaker" as I have never seen any reference on the web stating that it has built in overcurrent protection. The Orange 10 AWG may be capable of handling eight 600 watts lighting ballasts, but if your intentions is to is to run eight 1000 watts ballasts from that one lighting controller, you will need a cable capable of handling 50 amps (6 AWG) protected by a double pole 50 amp circuit breaker. Perhaps one of the sparky in the RIU forums could give you his definition of "for commercial use". Forgive me for being cynical, but I'm incline to believe that the use of the phrase "for commercial use" could be disclaimer in disguise by the manufacturer to protect the manufacturer for liability in the event a buyer is using that product for residential use.
i use the Sentinel GPS- has a built in timer (24 hr @ 15 min), and two zones, you dont need the 120v timer, and i got mine for $208 i think. only thing is its not digital, but i like the old school manual. plus no need for the extra timer or wires, its all built in
i had an electrician tell me the 10 awg would be fine, i guess he did some calculations, what leads you to beileve it requires a higher gauge than 10 ? the lights are pulling 4.25 amps each x 8 is under 40a, so 50 amp breaker is perfect, i dont ever expect them to pull more than 40a anyways ? my calulations are saying ill pull 34a, which should be fine @ 8 or 10awg?
Please note in your illustration in post #24 above "To 240V 50 AMP 3+G Power Source". The circuit breaker should not be sized to more than the allowable ampacity of the wire. It appears to me that your electrician is using the CEC (Canadian Electrical Code) wire ampacities chart. I was citing from the NEC (National Electrical Code) assuming that you are living in the United States. The NEC definitely restrict the use of 14AWG, 12AWG, 10AWG to 60C ampacity. Use of NM-B type cable in the U.S. does have some restrictions imposed by the NEC to limit it use to 60C ampacity, which is why I was hesitant to suggest 8AWG cable. I'm not an electrician by trade, but I hear some electricians in the RIU forums saying you can use it as a 75C feeder to a sub-panel. You and your electrician seem to think that the most combine amps your ballasts will be drawing is 34 amps, but have you and your electrician actually look at the data plate on the ballasts to get the actual amp draw information?
It is not necessary to go to the extreme of investing in a kill-a-watt meter. I am confident that you will be drawing under 40 amps. The issue I am more concern about is when the ampere load is exceeding 80% of the allowable ampacity of a given wire size, heat is generated in the wire and at the terminal connections. Express in other words, it can be stated that the ampacity size of the wire and the circuit breaker should be 125% of the anticipated load. I guess I have learn my lesson today to not get involved with another man's sparky, unless I am prepared to give elaborate replies. You can google NEC Table 310.16 or the newer 2011 edition NEC Table 310.15(B)(16) for more information. Do not use the 90C column for the allowable ampacity. The 90C column is used for derating calculations only. I have no idea of what is in the CEC wire ampacities chart, as I am unable to find it on the web.