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Tangible Ways Power Conditioning Can Improve Your Installation

Power conditioning is important, but not for the reasons you may be led to believe.

Anthony Grimani ([email protected]) is president of Performance Media Industries, with offices in Novato, CA, and Paris, France. Power conditioning is important, but not for the reasons you may be led to believe. For all their esoteric eloquence, power conditioning companies don’t always tout the true benefits of their products.

There are several facets of power conditioning that produce tangible and valuable results: isolation, noise filtration, voltage regulation, surge suppression, and distance monitoring. Each system that you install needs to have these components. Sometimes they all come in one package; other times you’ll need multiple devices. Cheap products usually don’t do a very good job, but some very expensive models don’t either. Compare specs, ask questions, and evaluate the responses. If you get numbers and data, you’re probably on the right track. If it’s just rhetoric, you may want to look elsewhere.

Good power conditioning begins with the isolation transformer. Its performance must be better than the 50-100 feet of 10- or 12-gauge cable between the transformer tap on the pole (or underground) and your system. This is accomplished by using a transformer with low-output impedance. It needs to behave like a rock, meaning that the voltage output is rock solid regardless of the varying current demand.

Speaking of current, the transformer must have enough capacity to deliver what your system needs. You may choose to drop some less sensitive power monsters like amplifiers off the transformer to keep its size and cost down. That’s OK, but the ideal solution is a transformer that will handle “everything.” Unfortunately, “everything” is a little vague; it could be either the maximum draw possible from the system (which is unlikely to ever happen) or the typical draw during normal operation. It’s your call which to use based on the situation and budget. Don’t forget to include the power factor. If you don’t know what that is, I highly recommend that you consult an electrical engineer to help with your power calculations.

Filtering Noise

Introduced in 2011, SurgeX’s XU315-DC is an online 1500 VA double conversion UPS/surge eliminator. The transformer can also act as a noise filter. It’s possible to do this without filter caps; the transformer itself can be an inductive low-pass filter above 1 kHz. Some methods work better than others. One manufacturer published an experiment using an oscilloscope on the line to compare residual noise with different products filtering it. Some let only a few mV through, while others were up in the 100s. It’s unproven if that noise is audible when it gets inside audio gear, but it can definitely cause errors in the sensitive microprocessors of automation systems. Ever wondered why automated lights go on and off with no bidding? It could be the power. Check noise rejection specs, and choose the highest values.

Voltage Regulation

Regardless of swings up and down in the input voltage, the output voltage stays the same. There are a number of ways to accomplish this. One method is to use a motorized transformer. This tends to be slow and rather inefficient. Another way involves switching between multiple taps a few volts apart. The more sophisticated switching supplies use advanced crossfade techniques to ensure that there are no transients when the supply changes. The important thing to remember is that slow response is bad, but so are fast snaps on the line.

Surge Suppression

Surge suppression basically means lightning strike filtration. Nobody really cares about a surge from 115V to 125V. Lightning is an entirely different matter. It ruins gear and leads to hours and hours of testing and replacing. The key factors to look for in surge suppressors are the response time (faster is obviously better) and how the spike is routed to ground. You want all of that high-voltage spike to end up in the ground, not your equipment. Again, there are better and worse ways to do this. Look for propaganda and evaluate effectiveness.

Some products provide internet-based distance monitoring. That means that you can get warnings of problems with power without leaving your office, and that you can log into the conditioner and monitor the client’s voltage conditions. You can even do a reboot of the gear from your office.

Good power conditioning may subtly improve sound and picture by reducing noise and eliminating some potential for ground loops, but I can’t promise it’s going to be a revelation in quality like the manufacturers claim. However, it will make all your systems run more reliably and last longer. That is where the true value lies. In addition to adding $10K or so in equipment, you’ll have fewer service calls and less gear to replace. With their systems up and running all the time, your clients will be happy and stop bugging you, so you can get to that massive pile of work stacking up on your desk.

Chase Walton contributed to this column.