I already have an Onan diesel generator:
Is it just a big zener diode?
i
Very interesting, I am reading it.
I must note: when a lightning hit the tree next to our house, all out computers and all electronics were on UPSes. None was hurt. The board in the AC controller, though, did get fried.
i
The only true protecction from lightning is to unplug your tv and other critical electronics during a thunderstorm.
Other places to inquire about lightning protection are rec.radio.shortwave
Damage is about a complete electrical path. Some things are in that path created by lightning and might be damaged Others are not.
Why a single point ground? Learn why cows, for example, are killed by a tree strike. Lightning did not hit the cow. Why did the cow die? Because electricity also flowed through the cow. Shortest electrical path was from cloud, to tree, into earth, up cow's hind leg, down cow's fore leg, then on to earthborne charges located maybe miles away.
So what in your house would have been in that same electrical path? Apparently the AC controller was in a destructive path. Maybe incoming up from earth - then outgoing via breaker box earth ground. Other electronics were not in a complete circuit - therefore not damaged.
How do we protect a cow? Surround a cow with a buried earth ground - a halo ground. Cow is standing on equipotential earth. How to protect your AC controller? Same. Another example of why we demand single point ground. Is your case, a halo ground - part of the single point earthing system - would make earth beneath that AC controller equipotential.
BTW, if we built homes to protect transistors, then Ufer grounds would be standard. Unfortunately, protection is still an after thought - which is why APC sells protectors at tens of times more money per protected appliance.
This also explains why buildings with utilities connected to different earth grounds may suffer damage.
There is no magic force that caused damage. Smoke detectors and GFCIs - not on APC protectors - also were not damaged. What protected them? Same thing that protected other electronics. APC hopes you never learn this.
Your question only listed selective examples. Good science includes the entire list of damaged and undamaged transistors. That APC solution provided no effective protection. Why? Electronics already have effective internal protection. Protection that may be overwhelmed without a 'building wide' protection system involving 'whole house' protector and the most critical protection component - single point earth ground.
This c> Very interesting, I am reading it.
During a potentially destructive transient, the effective 'shunt mode' protector converts from an open switch to a conductive wire. Notice what a protector does. It does not stop, block, or absorb surges as the APC product hopes you will assume. The more conductive that 'wire' (the protector), then higher is its joules. But earth ground is the bottleneck - which is why a protector is only as effective as its earth ground.
Of course, the APC has no effective earthing. So they avoid the discussion - entirely. They hype only enough numbers that confuse - such as response time. Let's look at another of those numbers. How many joules in that APC? Why is it so woefully small?
The 'whole house' protector, > Is it just a big zener diode?
Disconnection involves something very unreliable - humans. Effective protection is installed so that direct strikes don't cause damage. Newsgroups include rec.radio.amateur.antenna and alt.home.automation where those with technical knowledge and some with decades of professional experience post.
Those with knowledge (that is not always demonstrated in rec.radio.shortwave) will post as exampled:
I still stand by my statement. Connection to the grid introduces uncertainty. Also, a radio station may have many thousands of dollars of equipment and professional manpower. A home user will generally not want to do what a radio staion will do.
It is not practical to expect equipment to be disconnected during 100% of lightning storms.
i
Lightning is a funny thing from the standpoint of what it will damage and not. I had a lightning strike three feet from the A/C condensing unit and it blew out one circuit board in the A/C, noting else in the home was damaged. That included a number of electronic devices that are sensitive to surges. That was before I had whole house protection. It did trip the Circuit breaker for the A/C
I only had one UPS and two computers at the time, the one without the UPS was the only one turned on.
I suggest that you likely would not have suffered any damage, even without the UPS. I might also point out that it is very unlikely all your electronics were on UPS. Do you have a microwave, or digital clocks, etc?
If the guy cares so much about his equipment he'll either a) watch the weather reports and disconnect if there's storms predicted. b) spend large amounts of money insuring that he has the proper equipment and expertise to realistically survive a direct strike.
I think that a good point has been made that we cannot expect to be able to achieve 100% protection against lightning.
That said, if I can achieve some "good" protection, at not too high a cost, I will be happy with that. Again, it is unrealistic to expect that I will constantly monitor weather and turn off equipment when not in use.
I brought home four APC 2200 UPSes yesterday (some floor standing and some rackmount), that cost me $58 total. I am definitely going to use one on the living room electronics receptacle, as I have not heard any worthwhile objections so far.
I will use another one to protect the furnace circuit.
i"I brought home four APC 2200 UPSes yesterday (some floor standing and some rackmount), that cost me $58 total. I am definitely going to use one on the living room electronics receptacle, as I have not heard any worthwhile objections so far. I will use another one to protect the furnace circuit. "
Then I guess you think what Joseph, W-Tom and I told you isn't worhwhile.
Trip Lite respond fast 0-1 nanosecond and have circuitry that indicates if it is operational , if its hit and doesnt work its fixed free. Sure its a one line of defence, you need many, starting with grounds outside, a mains panel surge and even seperate lightning supressor. Do all you can and it may do nothing as lightning can energise the air and damage everything or overload everything. I was in a house when lightning lit up the lights in the kitchen for a second. All you can do is try things and pray. I unplug alot of things when danger is near, ive been through
3 hits.
Maybe I do not remember correctly, but as far as I recall, objections centered either around the cost of the units (not relevant to me), or mentioned that it would not offer sufficient protection without other devices.
Even if that is true (not offering proper lightning protection), I still can use the UPSes for other benefits (continued power), along with other protection systems.
i
Have you checked the current draw of that furnace??? That power supply has a max of 1600W and at that it is only good for less than 10 minutes.
I have not checked it in detail, but I think that all that the furnace has is a bunch of electronics, gas valves, and 1/3 HP blower motor. Should be easily run off the 2200 VA UPS.
Am I missing something? Thanks
i"Even if that is true (not offering proper lightning protection), I still can use the UPSes for other benefits (continued power), along with other protection systems. "
Yeah, that makes a lot of sense. Instead of putting in simple effective protection by installing a whole house surge protector, you're gonna try to run a TV and a furnace off a UPS. Put those UPS's on Ebay and use the money for the whole house surge protector.
Well, perhaps I was unclear, but I think that a whole house surge protector is a great idea!
I just do not feel that a WHSP and use of UPSes is mutually exclusive.
I will probably sell one UPS, salvage parts from another UPS and keep two -- one for the furnace and network stuff in the furnace room, and one for the family room electronics receptacle.
In addition, yes, I will look for a whole house surge protector. Any suggestions?
i
A 1/3 HP can draw over 7 amps and that would give you about 20 minutes max run time with a battery still having full capacity, batteries loose capacity as the age. I would say you would be lucky to get 10 minutes out of it.
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