HID Ballasts
Marijuana Horticulture
by Jorge Cervantes
A ballast regulates specific starting requirements and line voltage for specific HID lamps. Wattages from 150-1100 use old-fashioned coil transformer-type ballasts. Smaller wattages – below 100 – use energy efficient electronic ballasts. Electronic ballasts run cool and quiet. Scientists continue to develop electronic ballasts for larger wattage HIDs, but the failure rate is still very high. It is very important to buy the proper ballast for your HID. Smart growers buy the entire HID system – ballast, amp, socket, connecting wiring, and timer – at the same time from a reputable supplier to ensure the ballast and lamp go together.
Be careful when purchasing ballasts that are made in China or Asia, in general. Many of these ballasts are poorly made and do not meet local safety standards. Do not be tricked by misleading sales phrases such as “all components UL or CSA approved”. Of course, each of the components could be UL or CSA approved, but when the components are used together to operate a lamp, they are not UL or CSA approved. Furthermore, chances are that if components are approved, they are not approved for the specific application. Cheap transformers, capacitors, and starters are cheap because they are of inferior quality.
Do not try t mix and match ballasts and amps. Just because a amp fits a socket attached to a ballast, does not mean it will work properly in it. If you use the wrong ballast, capacitor, or starter with a amp, the lamp will not produced the rated amount of light, and it will burn out sooner. The wrong amp plugged into the wrong ballast adds up to a burnout!
The “core”, or transformer, consists of metal pates stuck together by resin and wound with copper wire. The capacitor can is on the right under the connecting wires.
More economical ballasts kits contain a transformer core, capacitor (HPS and some metal halides), starter, containing box, and, sometimes, wire. You can purchase components separately from an electrical supply store, but it’s a bigger hassle than it’s worth. If unfamiliar with electrical component assembly and reading wiring diagrams, purchase the assembled ballast in a package containing the lamp and hood from one of the many HID distributors.
Do not buy used parts from a junkyard or try to use a ballast if unsure of its capacity. Just because a bulb fits a socket attached to a ballast, does not mean that it is a proper system. One of the most miserable gardens I have ever seen was grown with mercury vapor streetlights and makeshift reflective hoods. The grower was low on money, so he pilfered all the street lamps, ballast and all, in front of his house.
Even though HIDs have specific ballasting requirements, the ballasts have a good deal in common.The most common characteristics ballasts share are noise and heat. This noise could drive some people to great fits of paranoia! Ballasts operate at 90-150F. Touch a “strike anywhere” kitchen match to the side to check if its too hot. If the match lights, the ballast is too hot and should be taken int shop for assessment. A ballast that runs too hot is noisy and could cause problems or burn out. Heat is the number one ballast destroyer. Many ballasts are manufactured with a protective metal box. This outer shell safely contains the core, capacitor, and wiring. If you build another box around the ballast to dampen noise, make sure there is plenty of air circulation. If the ballast runs too hot, it will be inefficient, burn out prematurely, and maybe even start a fire!
More expensive ballasts are equipped with ventilation fans to maintain col operating temperatures. Air vents allow a ballast to run cooler. The vents should protect the internal parts and prevent water from splashing in.
Some industrial ballasts are sealed in fiberglass or similar material to make the waterproof. These ballasts are not recommended. They were designed fr outdoor use where heat buildup is not a problem. Indoors, the protection of the sealed unit from weather is unnecessary and creates excessive heat and inefficient operation.
A handle will make the ballast easy to move. A small 400-watt halide ballast weighs about 30 pounds, and a large 1000-watt HP sodium ballast tips the scales at about 55 pounds. This small, heavy box is awkward to move without a handle.
Most ballasts sold by HID stores are “singe tap” and setup for 120 volt household current in North America or 240 volts in Europe, Australia, and New Zealand. North American ballasts run at 60 cycles per minute, while European, Australian, and New Zealand models run at 50 cycles per minute. A ballast from Europe, Australia, or New Zealand will not work properly at 60 cycles per minute. Some “multi-tap” or “quad-tap” ballasts are ready for 120 or 240 volt service. Single-tap ballasts accommodate only one voltage, usually 120. Multi-tap ballasts accommodate either 120 or 240 volt service.
It is generally easiest to use the regular 120-volt systems, because their outlets are more common. the 240-volt systems are normally used in Europe, Australia, and New Zealand or in North America with several lamps are already taking up space on other 120-vlt 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-vlt tap. “Singe tap” ballasts cannot change operating voltages. Consult the wiring diagram found on each transformer for specific instructions. The is no difference in the electricity consumed by using either 120 or 240 volt systems.
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 pace it up ff 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 t 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 cause by vibrations. Train a fan on ballasts to col 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 t move. Help control heat by placing it on or near the floor to radiate heat in a col portion of the grow room, or move the ballast outside the garden t 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 amp.
Ballasts may be manufactured with an attached timer. These units are very convenient, but the time should be constructed of heavy duty heat resistant materials. if it is lightweight plastic, it could easily met under the heat of the ballast.
Ballasts with a switch allow growers t 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 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.