Lightning and surge arrestors
- Thread starter TEC
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- Placerville, CA, USA
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ron
Senior Member
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- New York, 40.7514,-73.9925
I think both are called surge protection devices, no? Why would there be two for one panel?
gar
Senior Member
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- Ann Arbor, Michigan
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- EE
141125-1504 EST
How does a lightning arrestor differ from a surge suppressor? Are they really different functions? In some ways. And is a surge suppressor really a surge suppressor. What is a surge?
These are questions that need derinitions. Even though connection is specified thru a breaker, then do you get protection?
Suppose you have an MOV (surge suppressor) connected thru a 20 A breaker, and line voltage increases on a sustained basis to a voltage where the MOV has a current of 15 A thru it. This is insufficient to trip the 20 A or main breaker. Suppose this point is 150 V. Then power dissipated in the MOV is 15*150 2250 W. In all probability that MOV goes into thermal runaway and explodes. Should this type of voltage change be classified as a surge?
I just brought up these various items because I think it is generally assumed this is the way to solve the problems, but I generally think a lot more needs to be done to reasonably protect yourself. On the other hand in 60 years I have two instances where a lightning problem occurred. In one case 40 years ago with no kind of lighting or surge protection I had RS232 components destroyed at two ends of a 40 ft cable. In the other case a few years ago my home whole house surge suppressor did not prevent some internal damage to a TV.
Ten or fifteen years ago there was a good discussion on lightning protection of ham equipment. The discussion is no longer there. Basically it was directed at keeping the high frequency high voltage short duration energy from getting into the building,
This does not directly address your question, but I would put both on the same breaker. Others may differ. More discussion is needed.
.
How does a lightning arrestor differ from a surge suppressor? Are they really different functions? In some ways. And is a surge suppressor really a surge suppressor. What is a surge?
These are questions that need derinitions. Even though connection is specified thru a breaker, then do you get protection?
Suppose you have an MOV (surge suppressor) connected thru a 20 A breaker, and line voltage increases on a sustained basis to a voltage where the MOV has a current of 15 A thru it. This is insufficient to trip the 20 A or main breaker. Suppose this point is 150 V. Then power dissipated in the MOV is 15*150 2250 W. In all probability that MOV goes into thermal runaway and explodes. Should this type of voltage change be classified as a surge?
I just brought up these various items because I think it is generally assumed this is the way to solve the problems, but I generally think a lot more needs to be done to reasonably protect yourself. On the other hand in 60 years I have two instances where a lightning problem occurred. In one case 40 years ago with no kind of lighting or surge protection I had RS232 components destroyed at two ends of a 40 ft cable. In the other case a few years ago my home whole house surge suppressor did not prevent some internal damage to a TV.
Ten or fifteen years ago there was a good discussion on lightning protection of ham equipment. The discussion is no longer there. Basically it was directed at keeping the high frequency high voltage short duration energy from getting into the building,
This does not directly address your question, but I would put both on the same breaker. Others may differ. More discussion is needed.
.
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