This will be a shorter post than the previous, but equally as important in your grow room design!

Let me first explain a couple of terms I will be using. I am NOT an electrical engineer or physicist, but have been around some of the most knowledgable folks in the business my entire life, and have picked up a few helpful things along the way.

EMC: Electro-Magnetic Compatibility - this is in essence the "science" of making sure all of your electrical and electronic devices get along well, together in the same place.

EMI: Electro-Magnetic Interference - this is the stuff you don't want! For example, have you ever turned on a hair blow-dryer and watched as the TV screen went nuts? Yep, that is a perfect example of EMI, and in that case CONDUCTED EMI via the electrical wiring in the house, as well as RADIATED emissions.

We want EMC, we don't want EMI!

EMI is produced any time a device has an electrical current running through it, or it turns/revolves, creating it's own electrical field.

HID magnetic ballasts can be some of the most serious offenders of EMI! You have a big magnetic coil getting ramped-up inside that case, supplying voltages to your fixture. Wavelength and wave form can be modified by the ballast in some cases, which creates additional emissions issues, both conducted and radiated.

The concern with these ballasts is primarily the MAGNETIC fields.

Wikipedia defines this as: "In physics, the magnetic field is a field that permeates space and which exerts a magnetic force on moving electric charges and magnetic dipoles. Magnetic fields surround electric currents, magnetic dipoles, and changing electric fields." (If you look up "Magnetic Field" on Wikipedia you can review all the physics and algorithms if you wish...me? I don't speak mathematics!)

To be safest, locate your ballasts away from places where people congregate or sit...at least 3 ft. (1 meter) minimum. The Magnetic field generally does not extend beyond this distance from an source. DO NOT put it under your chair or bed while operating!

For electrical safety the ballast should not be located on the ground. Set it on a shelf or make one. A ballast on the floor in a room where water is frequently (or always) found is a disaster waiting to happen. If you spill enough water on the garage floor, and it is heading for your ballast, TURN THE BREAKERS OFF before it gets there, or it will turn them off itself as it shorts out and possibly BURNS up, along with ????. (Yeah...explain that one to the fire dept!)

If you do have to turn the breakers off, but sure to allow enough time for the lamp to cool (15 min.) before you re-fire the HID lamp.

I have yet to find any Magnetic Ballast that provides information on the EMC testing that it has undergone. These test are required by governing agencies around the world, and while some products can "slip by", but be sure to look into what standards the ballast has been tested to. They do vary from country to country (EU and Asia have stricter standards than the US, as a rule).

So, to keep this part short...don't be sleeping or hugging your magnetic ballast while it is operating and all of your future children will have the appropriate amount of arms, legs and other parts.

Digital ballasts have come a LONG ways towards making ballasts safer, and some companies (Euro-Systems, Lumatek etc.) incorporate both digital and magnetic components inside a well-shielded ballast case, greatly reducing the EMI and they also actually TEST their products to insure compliance with existing safety standards.

Another big source of EMI is FANS. Fans with exposed motor drives (in-line style) are the most susceptible to creating unwanted fields. You can not see these fields, but they do effect things around them. Try to use UL listed fans at every location. If a fan or other device does not provide any proof of being electrically or RF safe, I won't buy it.

If you are having severe CONDUCTED emissions issues (fan bleeding into your radio, etc.) you can add a supressor to the outlet where the device plugs in. The device still radiates/conducts the interference, however the filter at the plug keeps this radiation from continuing down the lines and effecting other devices.

Don't risk your health while growing what saves your health!


ISO

__________________