news / tech talk

Surge Protection

by Lee LeClair
As seen in Inside Tucson Business

I have talked previously about various power issues associated with IT. Uninterruptible Power Supplies (UPS), generators, etc. are all part of keeping IT in order and operating all the time. As usual, Arizona’s recent weather and related power outages have given me cause for further research. One would think I would have learned all there is to know by now since our monsoons and heavy electrical storms typically cause several small scale power outages each year.
What I learned from our most recent power outage was about surge protectors. Specifically, most UPS systems do not really have them except possibly in a very rudimentary form (a fuse). Also, typical power strip surge protectors from the local hardware store are not too reliable even for workstation protection. Most office supply power strip surge protectors use metal oxide varistors (MOVs) for surge protection. These are made up of a decaying type of material that degrades with use but offers no indicator of how many uses have occurred or how many uses are left but most will not withstand 100 surges (not strikes but voltage variations). Every time there is a power “event”, the MOV is degraded. By event, I do not necessarily mean a full blown power outage, but “brown-outs” or upticks in power; the type that occur all the time for any number of reasons (turning on a vacuum cleaner, the fridge kicking on, the coffee maker starting up, etc.).

In addition, most of these cheap surge protectors work by sending any power spike back through the ground or neutral wire. With multiple interconnected systems, this is not a particularly great thing since they share that ground. In addition, low grade surge protectors do not really provide an electrical rating that means anything. How much of a jolt could they handle? A lightning strike? Not likely and not that you will be able to tell from the poor rating information they provide on their packaging. The bottom line is that if you value your IT assets and need them to operate without weird problems after power surges, outages, and powering back on, then you need to consider a higher grade system.

In 1996, the government issued new Underwriters Laboratories (UL) tests for surge protectors because of the generally poor performance and standards associated with power surge testing. Based on these standards, the best commercial surge protector should be able to withstand 1000 lightning strikes (6000Volts at 3000 Amps) without degradation, should not vent the power through the ground wire (this is acceptable for some uses but I would not recommend it for IT unless you want to fry your network), and should not allow more than 330V through to the protected equipment. That would be a Transient Voltage Surge Suppressor (TVSS) of Class 1, Grade A , Mode 1 – the best there is. If you go the route of high grade surge protection, put them in place on your electrical circuit before a UPS so that device is also protected. Models vary depending on the physical application (rackmount, free-standing, etc.) and the circuit current you will be using (typically 15Amp or 20Amp).

The next natural question is regarding the cost of this protection. Make no mistake, it is not cheap. For inexpensive systems ($29.95), there is always the hardware or office supply surge suppressor. A commercial grade protector meeting the highest UL specifications described above will cost in the neighborhood of $150 and go up from there. If your servers, data, and availability are worth protecting and especially if you live in Arizona, then I would recommend looking into high grade commercial surge suppressors to keep your systems safe and humming along.

Lee Le Clair is the CTO at Ephibian. His Tech Talk column appears the third week of each month in Inside Tucson Business