Marijuana Horticulture: The Indoor/Outdoor Medical Grower's Bible

Zealand or in North America when several lamps are already taking up space on other 120-volt circuits. Changing a “multi-tap” ballast from 120 volts to 240 volts is a simple matter of moving the wire from the 120-volt tap to the 240-volt tap. “Single-tap” ballasts cannot change operating voltages. Consult the wiring diagram found on each transformer for specific instructions. There is no difference in the electricity consumed by using either 120 or 240-volt systems. The 120-volt system draws about 9.6 amperes, and an HID on a 240-volt current draws about 4.3 amperes. Both use the same amount of electricity. Work out the details yourself using the chart below.
    The ballast has a lot of electricity flowing through it. Do not touch the ballast when operating. Do not place the ballast directly on a damp floor or any floor that might get wet and conduct electricity. Always place it up off the floor, and protect it from possible moisture. The ballast should be suspended in the air or on a shelf attached to the wall. It does not have to be very high off the ground, just far enough to keep it dry.
    Place the ballast on a soft foam pad to absorb vibrations and lower decibel sound output. Loose components inside the ballast can be tightened to further deaden noise caused by vibrations. Train a fan on ballasts to cool them. Cooler ballasts are more efficient, and bulbs burn brighter.
    Ballasts can be attached to the light fixture remote. The remote ballast offers the most versatility and is the best choice for most indoor grow shows. A remote ballast is easy to move. Help control heat by placing it on or near the floor to radiate heat in a cool portion of the grow room, or move the ballast outside the garden to cool the room. Attached ballasts are fixed to the hood; they require more overhead space, are very heavy, and tend to create more heat around the lamp.
    Ballasts may be manufactured with an attached timer. These units are very convenient, but the timer should be constructed of heavy-duty heat-resistant materials. If it is lightweight plastic, it could easily melt under the heat of the ballast.

This grower lost the crop! He also almost lost his life! Pay attention to electrical connections, ampere ratings for wire, breaker switches, and connectors.

Stoners have a way of making simple things complex.
    Ballasts with a switch allow growers to use the same ballast with two different sets of lights. This wonderful invention is perfect for running two flowering grow rooms. The lights go on for 12 hours in one grow room while they are off in a second room. When the lights turn off in the first room, the same ballasts hooked to another set of lights in the second room are turned on. This setup is very popular in Canada.
    There are also ballasts to run both metal halide and HP sodium systems. These dual-purpose ballasts are not a good idea. They will work, but they generally over-drive the metal halide bulb causing it to burn out prematurely after accelerated lumen output loss. I do not recommend these types of ballasts. If you have a limited budget and can only afford one transformer, use conversion bulbs to change spectrum. (See Conversion Bulbs).
HID Bulbs
    Many new HID bulbs have been developed in the last few years. The most notable have been the 430-watt HP sodium, pulse start metal halides, the AgroSun, SunMaster PAR bulbs, and the 1100-watt metal halide. These HID bulbs are also available with many different outer envelopes, so bulbs can fit into more confining reflective hoods.
    High intensity discharge bulbs are rated by wattage and by the size of the outer envelope or bulb.
    High intensity discharge bulbs come in different shapes and sizes. Below each bulb are the numbers industry uses to define their shape and size.
    In general, HID bulbs are designed to be tough and durable. New bulbs are tougher than used bulbs. Once the bulb has been used a few hours, the arc tube blackens, and the internal parts become somewhat brittle. After a bulb has been used several hundred hours, a good bump will substantially shorten its life and lessen its luminescence.
     
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Ohms Power Law:
Volts × Amperes = Watts
    115 volts × 9 amperes = 1035 watts
    240 volts × 4 amperes = 960 watts
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    Never remove a warm lamp. Heat expands the metal mogul base within the socket. A hot bulb is more difficult to remove, and it must be forced. Special electrical grease is available to lubricate sockets (Vaseline works too). Lightly