Disklavier

Greetings MichaelFirst,

I don't have lightening in California much but I do have the worlds worse electrical distribution system and have had many power surges (technically the surges are so sustained that they are called "faults") which have destroyed thousands of dollars worth of equipment each year. I got tired of putting in claims so I did some research and found out some things about surge protectors and got some good ones. Here are some things that I learned that apply with varying degrees to other situations.

Most "surge" protectors are total crap. They depend on metal oxide varistors (MOVs) which are good for protection but have severs limits that make them less than ideal protection. They work by becoming conductive when the voltage across them exceeds a certain threshold. When this happens, they absorb the energy of the surge by dissipating it as heat. Some of the problems are: 1 they have their limits in energy absorbed (they are rated in joules and this is something to look at when comparing models) but none will absorb the huge amount of energy that you can get in a lightening strike or a sustained "fault". 2 they loose their ability to protect as they are subjected to surges. there is no way to tell if a device has absorbed too many surges to still offer protection. the "protected" idiot lights mean nothing about the remaining ability to offer protection. all you can do is replace them often or more often if you do have a lot of surges or strikes. 3 they can fail in a shorted mode as opposed to an open condition. this means that a MOV can short circuit and start a fire. this happened to me and fortunately I was there to turn the power off before the house was on fire.

Only one company makes a consumer price device that offers better protection against power line surges (more later about why power line protection is important even for phone line surges) Panamax makes a line of protectors (not all have of their products have this feature) that have a voltage sensing circuit that disconnects the load from the line if the voltage goes either above or below a sensibly chosen threshold. Not only does this protect better against "faults" but it protects the MOVs from sustained stress that can cause them to loose their effectiveness. I have about 15 of these protectors on everything that I value in the house and have not lost anything since even though there have been faults. There was one exception that must be mentioned and it is not the fault of the protector but the fault of the piece of crap it was protecting. During a storm a couple of years ago a power line was partially cut creating what the utility company calls a "floater". The voltage went up and down many times during the night. The refrigerator was "protected" by one of the "Protect or Disconnect" surge protectors which did its job of switching off when the voltage went low and switching on when it went to a normal level. Any decent refrigerator has a time delay circuit to prevent "short cycling" so i was not concerned. My new stainless steel designer unit didn't. It would not have even cost a penny to add this feature since the control circuit is microcontroller driven and could have been programmed with an on delay. It wasn't so the compressor started against high back pressure many times and burned itself up. the refer now has a start delay that I installed. Just mentioning this because it is the only problem that can happen with these protectors but the condition that caused it is probably quite rare. Still best to check any refer plugged into one of these.

Telephone lines are better protected with different types of devices. Commercial phone line protection is available and most phone companies have pretty decent protection anyway but... Older devices are not as good as the new types especially if they have been stressed. the old carbon based protectors are good when new but they definitely loose their effectiveness age, corrosion or repeated stresses. The new types are spark gaps sealed in inert gas filled tubes. These are very reliable. Ask you phone company (good luck especially if it is Verizon) to replace your Network interface with a new one that has the "gas discharge" lightening protectors or buy your own. Be sure to follow the installation instructions and or check to see that the installer does it properly. Little details such as the size of the ground wire, the ground it is connected to and even the path of (no sharp bends etc etc) of the ground wire will determine whether it will help against lightening strikes or not.

I made my own protection for the phone line because I have crappy phone service as well as power (ah the blessings of country life) and have occasional surges on the phone line as well. My protection consists of a combination of MOVs and very low current fast acting fuses. I think I used 10 ma fuses but they would have to be larger if you have old fashioned phones with electromagnetic ringers. the fuses come after the spark gap (gas discharge) lightening protectors and are on both the tip and the ring wires. After the fuses are three MOVs one between the fuses and one from each line to ground. All MOVs are on the phone side of the fuses. I use a separate ground stake located far from the building ground. This is because a MOV on the power line can put a huge surge into the building ground and if there is any problem there, it will go right from the MOVs protecting the phone into the phone line. I lost a computer this way once using a commercial surge protector that had both line and phone protection in one box. DO NOT USE THESE Use separate phone and power line protection with separate grounds. The phone company is likely to use the building ground for their protection but installing the fuses I recommend along with MOVs will help protect against this. Also,the gas discharge lightening protectors are not as likely to feed the power line surge at the ground back into the phone line as are MOVs but I still recommend separate grounds if possible.

Do not connect anything that you value to the phone line especially if you live in a lightening prone area. Use a wireless connection for networks. Wireless can be a pain but lightening can not jump across it :) Unplug anything during a lightening storm especially the phone line connected stuff. If you are leaving and can not get back to the house to disconnect things should a lightening storm arrive, disconnect it before you leave. This winter I only lost my (replaceable) telephone systems because I wanted then to be taking messages while I was gone. they died from powerline surges not phone line surges for which there was adequate protection. Next winter I will plug them into the Panamax surge protectors. I hadn't because I hadn't thought they were vulnerable or expensive enough to worry about. The chest freezer was on the line when the power surged and being an old monster, survived it but tripped the breaker when the surge caused it to draw too much current due to the voltage increase (I get 5 to 1 faults due to fault distribution construction) When the power was restored, the breaker did not reset so I came home to a lovely box full of blue chickens and other interesting cultures. Next year, the freezer will either be off or connected to a Panamax. It may not act fast enough to prevent the circuit breaker from tripping but it might. While I was gone I had an electric heater on to to keep the piano happy but I was concerned about leaving an electric heater on for months so I installed an arc fault circuit interrupter. The heater was plugged into a Panamax as well. Whatever the surge (fault) did, it tripped the arc fault breaker. Therefore I had no heat for the piano for about a month of very cold winter. It survived but required a very major regulation and tuning. Next year I will know to ask the neighbors to check the piano heater if there are snow storms.

I will play Earl Wild's Favorite Chopin CD for you.

Wednesday, May 13, 2009, 8:24:04 PM, you wrote: