Power Spike Arrestors And PLCs
Editor Gary Comments: The following letter from Monster Cable are published in response to Part 3 of Doug Blackburn’s series on Power Conditioning which appeared in Issue 34 of Widescreen Review. The letters are self-explanatory and shed new light on the subject of power conditioning. Dear Gary: I have been following with interest your series on power line conditioners (PLCs) and I would like your advice in choosing a power arrestor. I am interested in protecting my equipment against surges, spikes, and lightning strikes. My understanding is that metal oxide varistors (MOVs) do not give the best protection since they degrade with time. Although brownouts are a concern, I think that short of power regenerators, there is nothing that one can do about that power supply anomaly. I am more concerned with protecting the equipment than with the vague improvements in sound and video that could be derived from standalone PLCs. If the surge suppressors have filters, so much the better. Your articles question some PLC’s ability to handle the current needed to drive large amplifiers. That is another consideration since I will be using a 5.1 receiver with 105-watts per channel. I am also connecting an RPTV, DVD, LD, VCR, DSS, CD, and turntable. Not all will be playing at the same time, of course. The PLC/arrestor units from Monster Cable and Current Design use MOVs. I have also read about units from Niles, Brick Wall, Tice, Powervar, and Transtector. The problem is that aside from the testimonials from the manufacturers, there is very little third party knowledge or information about these units. Your articles have in passing mentioned the arrestor properties of some of the equipment you have tested, but not enough to let me know how the units would perform when called to protect equipment. Of the units you have reviewed, and the units I mentioned above; which one, in your opinion, would best fulfill my needs? I am starting my budget at around $500.00 and would like to see something lower than that, if possible.
Casimiro Izquierdo,
Contributing Editor Doug Blackburn Comments:
The writer brings up a question so large that it would probably require at least a long two-part article on all the issues around protection of equipment from line surges. I will try to distill that massive undertaking into several points that best cover the issues. 1) Almost all audio related PLCs use "sacrificial" surge suppression devices. Each surge seen by these devices degrades the device slightly and eventually they will fail. In most cases, the failures would occur after decades of use, probably more than most people would subject them to. Brickwall products are a good choice if you feel that "non-sacrificial" surge suppression is what you want at a reasonable cost. This type of suppression should "last a lifetime." 2) Realistically, most people will get all the protection they need for as long as they need it (from surges) from any of the PLC products that were evaluated in Issue 33 and 34... the exceptions being the Quantum Life Symphony and the AudioPrism Quiet Line filters, which by their nature have no surge suppression at all. 3) That said, people tend to over-worry about potential damage from surges. Most audio equipment is completely impervious to the momentary surges of up to several hundred volts you can see on many power lines. The duration of these surges is so short, the equipment barely notices anything happened. You might hear a "click" or "tic" or at worst a little "pop" but that’s about it. 4) Lightning is the enemy, but only if you are "high risk" for lightning in your area. The more elevated your domicile, the more common lightning storms are; and the more exposed your domicile is, the better candidate you are for a lightning strike. Lightning rods would probably be a sensible choice for you since they can keep your house from burning down as a result of a lightening strike. Whole-house lightning protection is also available from many electrical contractors and may make more sense than only protecting your audio equipment. The cost is not necessarily more than the price of a good PLC. I’ve known two people who have had their homes hit by lightning in the last few years. Both had early Audio Power Power Wedge PLCs that were at least 6-years-old. In both cases, the Power Wedges stopped working after the lightning hit, but none of the equipment connected to the Power Wedge was harmed in any way. A trip back to API to have the suppressors replaced, and the Power Wedges were back in service. I believe that you would receive about the same level of protection from any of the true PLCs that were examined in Issues 33 and 34, with the exceptions noted above. As for this particular reader’s system and budget needs, I believe that I can make a solid recommendation. After the article in Issue 34, Monster Cable let me know that I had incorrectly characterized the High Current (amplifier) section of their top PLCs as having potentially current limiting common mode filters. In fact, there are no common mode filters in the High Current section of the HTS-3000/3500, and those PLCs will definitely deliver the current this 105-watt/ channel 5.1 receiver needs. In addition, you get Monster’s equipment insurance policy. The High Current section of the HTS-3000/ 3500 is basically hot-wired to the AC outlet with surge suppression and some non-current-limiting noise filtering. This makes the HTS-3000/3500 more suited to handle bigger amps than I recommended in Issue 34. I would revise my recommended limits to 160-watt/channel 5.1 receivers, 120-watt 5.1 amps and high current stereo amps up to 150-watts/channel. Bear in mind that these are my own personal "perfectionist" limits and don’t reflect the fact that the Monster PLCs can deliver, in theory, as much power as any 15 amp household outlet can deliver. Under maximum load conditions, there will be no fires or damage and the equipment will continue to operate just fine. But my observations are that your system will sound better if you stay well under the maximum continuous or peak ratings for most PLCs. By the way, this reader should add up the power draw for all of his equipment and convert it all to watts or amps. In the U.S., the formulas are watts = 120 volts x amps (listed on the back of some equipment) or amps = watts (listed on the back of some equipment)/120 volts. A typical household electrical outlet is good for up to 15 amps or 1800 watts (15 amps x 120 volts). If the 5.1 receiver draws up to 6 amps and the RPTV [rear projection] needs 600 watts and the other components run 30 watts each, the total wattage for this system would be 1500 with all receiver channels working to the max. This is close enough to the limit of 1800 watts on a 15 amp outlet that the reader may want to consider installing a 20 amp outlet to power this home theatre. This should be considered not out of necessity, but in the interest of under-rating the electrical circuit to get better audio sound quality. My observations so far are that video image quality is not sensitive to being on a circuit that is operating close to its maximum rating.
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