Power at Work: Surge protectors - peace of mind at a reasonable cost

Sunday, January 4, 2009

For anyone with electronic equipment in their home or farm, these devices provide cheap insurance against power surges caused by lightning strikes

by RALPH WINFIELD

Many of you now have a computer and an internet connection. I'll bet that most of you also have a surge protector on both the input hydro and telephone lines going to your internet system. The surge protection is often built into the power bar that you have sitting next to your system. In fact, you might not even know that it is there if it has not been "fried" yet.   

Please do not confuse surge protection with over-current protection (a breaker) that might also be in your power bar. They are NOT intended for the same purpose.
When my wife purchased a new treadmill a few years ago, the installer stated very clearly: "Protect it with a surge protector. If you don't, don't call for warranty coverage in the event of the wiring/electronics being destroyed."

Probably the greatest reason for needing surge protection is the possibility of lightning strikes on above-ground hydro, telephone and other cable services connected to your buildings.

After we installed our first submersible water pump in 1978, I became very aware of power surges caused by lightning strikes. On a number of occasions, we would have no water pressure after a thunder and lightning storm. What did I find? One or both line fuses to the pump were burned off from over-current flow. I would replace the fuse(s) and call the insurance company to advise that they might have a claim in the next week or 10 days if the water pump failed.

Other neighbours replaced submersible water pumps so frequently that they became a named item on the insurance policy – and still are. The good news is that, about 1980, all or most submersible water pump manufacturers started building lightning arrestors into the electrical circuitry of the pump to divert significant power surges. We, and those same neighbours, haven't had a water pump problem since we purchased the updated pumps.

Think about it for a minute. A high voltage power surge has to go to ground. What better path than a wired device suspended in ground water? That ground path beats any ground rod sitting in relatively dry soil.

Your utility – Hydro One for most of us – has a lightning arrestor located on the line side of every distribution transformer, at least every one in the rural area. If you look between the power line and the transformer at your farm, you will see a ceramic device with a wire bonded to the service ground at that location. The purpose is to protect their transformer from a power surge or think lightning strike. Unfortunately, it will not stop all surges, especially the smaller ones that can affect sensitive electronic equipment.

We live near London, often referred to as the Thunder Storm Capital of Canada so lightning storms are expected. On one occasion about three years ago, three of us along the road each had one surge protector wiped out during the same lightning storm.

Two of us lost only the surge protectors for our computer and internet systems with a replacement cost of about $30. The third party had a new broiler production unit with many electronic controls. His replacement cost was about $200. Interestingly enough, we were all on the same phase of the three-phase distribution supply lines that pass all three properties. Obviously, that one phase had picked up the surge.

So you can tell that I am a firm supporter of surge protectors on all voltage-sensitive electronic equipment. Yes, you can unplug some equipment when it is not being used, but what happens when you forget, leave home and a lightning storm occurs? Surge protectors provide very cheap insurance.

So which equipment should you buy? I suggest brand-name surge protectors that have impressive specifications and are approved by the Canadian Standards Association (CSA) for the application.

Being a bit of a pack rat, I just dug out the package for the replacement surge protector/power bar we bought about three years ago. Here are the pertinent Surge Suppression ratings:

• One nanosecond reaction time;
• Three modes of protection;
• 15,000 amp current peak;
• 1,650 joules energy absorption;
• 330 volt-clamping voltage (UL rating);
• EMI/RFI noise protection

This seven-outlet power bar also has a lighted on/off switch, a 15Amp. re-settable circuit breaker, an LED ground indicator and separate surge status indicator. Both LEDs are illuminated when functioning properly.

It is very important that the receptacle be properly grounded as the surge protector requires a good path to ground in order to dissipate the surge energy.
The power bar also has input/output wiring for a telephone line or coaxial TV protection. Several years ago, we lost a computer because the telephone line was not included in the surge protection bar.

In short, I recommend surge protectors to anyone with a computer, an internet connection, cable TV, any sophisticated electronic control system in livestock operations or grain drying/handling systems, and yes, even for the treadmill.

Many equipment manufacturers recommend that you unplug appliances when they are not in use. My memory is not as good as it used to be and
I have more important things to remember. Surge protectors do provide peace of mind at a reasonable cost. BF

Agricultural engineer Ralph Winfield farms at Belmont in Elgin County.