Well it finally happened at our house. A power outage and related voltage surge and damage.
Last Sunday evening, a narrow line of storms passed through the western Pennsylvania area. Some lightning/thunder, but mostly strong winds (50+ MPH gusts).
Around 8:30pm my wife was on the phone with a friend a few miles across town, and their power had just gone out. This was more or less the peak intensity of the storm.
Around 9:00pm, we just started to watch a video, when our power went out 'with a bang'. We attributed the bang to a transient on the A/V system. The power went out sharply. I even said that it was like it was turned off, probably for repairs....
OK, we have a small, manual genset to maintain a few circuits in the house like furnace, network, refrigerator/feezers, etc. So we're OK with the genset running occasionally throughout the night and next day. Around 6:00pm on Monday, we see that the neighbors have power, but we don't... Hmmm.
Before this point, never opened the cover to the service entrance panel. The genset feeds the house via a manual transfer switch outside of the service entrance panel.
Opening the panel cover, I see a distinct arc burned area on the cover and around the surge protector. I installed the type of surge protector that installs in a two-pole circuit breaker position, at the top of the bus-bar. And this SPD took a hit and tripped the 200A main breaker. Probably the sharp cutoff of power...
I wanted to get power restored, so I tried to reset the main breaker.... Well, another arc-flash from the SPD that just about knocked me off of the step-stool... Obviously the SPD was still shunted to ground. Looks like only one pole of it.
OK, so I removed the sacrificial SPD and replaced it with a spare two-pole breaker just to fill-up the space. THEN the main breaker was able to be reset, and we had shore-power.... Or so I thought so.
Looking at the branch CB's I saw several in the tripped position.... Did the surge trip them? Or did the power restoral trip them?? In fact, breakers tripped in several sub panels around the house. There's a 100A sub panel in a mechanical room. This feeds a 60A sub panel that houses a GFCI breaker for the spa. ALL breakers in this chain had tripped. The 100A feeder in the main panel. A 100A main breaker in the sub panel. A 60A breaker in this sub panel, and the 60A GFCI breaker in the spa disconnect panel.... Interesting.
And two branch circuits are still bad. One 15A lighting circuit won't reset. Breaker only trips. This circuit has a couple of electronic dimmers and timers. Maybe one of them is damaged. Another 20A circuit breaker 'buzzes' when I try to reset it. Damaged breaker?? This circuit only has two receptacles. One with a table lamp. Nothing sensitive.
Still investigating...
But we have learned that some of the neighbors in the area also had circuit breakers tripped.
Anyway, interesting situation... But looks like the house SPD took the brunt of the damage.
Last Sunday evening, a narrow line of storms passed through the western Pennsylvania area. Some lightning/thunder, but mostly strong winds (50+ MPH gusts).
Around 8:30pm my wife was on the phone with a friend a few miles across town, and their power had just gone out. This was more or less the peak intensity of the storm.
Around 9:00pm, we just started to watch a video, when our power went out 'with a bang'. We attributed the bang to a transient on the A/V system. The power went out sharply. I even said that it was like it was turned off, probably for repairs....
OK, we have a small, manual genset to maintain a few circuits in the house like furnace, network, refrigerator/feezers, etc. So we're OK with the genset running occasionally throughout the night and next day. Around 6:00pm on Monday, we see that the neighbors have power, but we don't... Hmmm.
Before this point, never opened the cover to the service entrance panel. The genset feeds the house via a manual transfer switch outside of the service entrance panel.
Opening the panel cover, I see a distinct arc burned area on the cover and around the surge protector. I installed the type of surge protector that installs in a two-pole circuit breaker position, at the top of the bus-bar. And this SPD took a hit and tripped the 200A main breaker. Probably the sharp cutoff of power...
I wanted to get power restored, so I tried to reset the main breaker.... Well, another arc-flash from the SPD that just about knocked me off of the step-stool... Obviously the SPD was still shunted to ground. Looks like only one pole of it.
OK, so I removed the sacrificial SPD and replaced it with a spare two-pole breaker just to fill-up the space. THEN the main breaker was able to be reset, and we had shore-power.... Or so I thought so.
Looking at the branch CB's I saw several in the tripped position.... Did the surge trip them? Or did the power restoral trip them?? In fact, breakers tripped in several sub panels around the house. There's a 100A sub panel in a mechanical room. This feeds a 60A sub panel that houses a GFCI breaker for the spa. ALL breakers in this chain had tripped. The 100A feeder in the main panel. A 100A main breaker in the sub panel. A 60A breaker in this sub panel, and the 60A GFCI breaker in the spa disconnect panel.... Interesting.
And two branch circuits are still bad. One 15A lighting circuit won't reset. Breaker only trips. This circuit has a couple of electronic dimmers and timers. Maybe one of them is damaged. Another 20A circuit breaker 'buzzes' when I try to reset it. Damaged breaker?? This circuit only has two receptacles. One with a table lamp. Nothing sensitive.
Still investigating...
But we have learned that some of the neighbors in the area also had circuit breakers tripped.
Anyway, interesting situation... But looks like the house SPD took the brunt of the damage.