hj Loc: Florida

Can anyone educate me on the Zap-Cap which supposedly protects the whole house from lightning strikes, power surges etc. I though I'd read you still have to use in house surge protectors, so what's the purpose of the Zap-Cap?

Longshadow Loc: Audubon, PA, United States

If it's anything like a "Zeus" that gets put on the breaker box feed...
A Zeus is a dual gas discharge tube that goes across leg A and leg B of your power line, to common.
If surge or spike greater than about 400 volts comes down either leg of the the power line the gas tube lights, discharging the surge. It is a surge/spike protector. Because the Zeus triggers at 400V you still need a smaller ones at the computer/electronics devices. NOTHING will protect your house from a direct lightning strike on your power feed. Absolutely nothing! Lightning hitting a tree will blow the tree apart - from the expansion of the steam created when the moisture in the tree boils, in an instant.

I was talking to the guy that installed one in my house in Florida, about lightning and the Zeus. (We had a master feed box outside, where the Zeus was installed.) He state that he did replace one on a house that got hit by lightning,... he found little pieces of the Zeus all over the yard. I don't remember what he said about what happened to the rest of the house though. Lightning hitting a tree will blow the tree apart - from the expansion of the steam created when the moisture in the tree boils, in an instant.

One time a lightning spike came down the phone line, lost a phone and a modem on that one (heard the characteristic SNAP). Once down the TV cable, lost the cable box and a VCR on that one.

It's more protection than nothing, but not a savior.

TriX Loc: Raleigh, NC

Zap Cap is a whole house surge protector rented by TepCo in Florida to its customers. From what I read, the cost is 7.95 per month and includes some reimbursement for damaged appliances under certain conditions if also supplemented by individual surge protectors for your electronic equipment. There are a number of customer complaints online about the exclusions to claims and the difficulty of being paid. Check Google for more details.

In general, surge protectors, other than a real UPS which provides conditioned power (NOT your <$100 UPS from Best Buy) is one of 3 technologies: MOVs, Transorbs, or Inductive suppressors.

MOVs are the most common and range from large whole house units to the small ones in your plug-in surge suppressor and almost every electronic device power supply. They have a clamping voltage, beyond which, they clamp the surge to ground. The downside of MOVs is that they have a limited number of clamping events and decrease in effectiveness as they age. They can also self destruct when subjected to continuous voltage beyond the clamping voltage.

Transorbs, are faster acting semiconductor devices that are designed to absorb fast spikes in voltage. They are faster acting than MOVs, but more limited in capacity, so they are often used in conjunction with MOVs.

Finally, inductive suppressors use inductors, which resist a change in current. They are probably the most useful of home suppressors, and do not deteriorate with age, but they are larger and more expensive.

Now, none of these devices are effective against a direct lightning strike, only the induced voltage surges related to a nearby strike or the regular surges and “blips” that occur on the AC power line. If you live in a lightning prone area like Florida, you need actual lightning arrestors on EVERY line that enters your house including cable and telephone lines, AND the best protection are professionally installed lightning rods with heavy gauge wide ground cables and a serious grounding system consisting of 8’ Ground rods in conductive soil which provide a “cone of protection” for your home. Entire books are published on lightning and surge protection, but this is a quick overview.

Longshadow Loc: Audubon, PA, United States

Interesting, I bought my Zeus, didn't "rent" it.

Longshadow Loc: Audubon, PA, United States

The surge protection is measured in joules (energy). MOVs and such that are in power stripe have a much lower joule rating than a Zeus or Zap Cap. but the MOVs usually trigger around 200 volts. Great for little blips. Faster response that a Zeus, but cannot handle the energy that a Zeus can handle. (Many higher joules).
When I lived in Florida, I had both. Here in PA, just the moves on the power strips.
I still unplug some things if a storm is real bad. Harder for lightning to jump to the plug when it is on the floor, but it CAN happen. There is no rhyme or reason as to what route lightning takes.

TriX Loc: Raleigh, NC

MOVs are typically sized a little above the line voltage, so you might use 135-150V for 120VAC phase to neutral and maybe a 250-260V for 230/240 VAC phase to phase. I can tell you from experience that they will smoke, burn and explode if subjected to constant voltage above their rating. We had a phase to neutral fault on the drop to our house putting 230V on one phase (to neutral) and wiping out 4K$ worth of electronics and appliances. Fortunately the computers were on the other phase. Every MOV, whether in the surge suppressors or the electronics, smoked and exploded. I had a whole house suppressor that I hadn’t installed yet, and I wonder what would have happened to those (potted in a NEMA plastic enclosure) - would they have caught fire, melting the enclosure?

Longshadow Loc: Audubon, PA, United States

I thought there were ones that went down to around 135V, just above line voltage. Little blips. Been so long since I've worked with them though.

As for your suppressor that wasn't installed - If it's anything like the Zeus my friend replaced - it would have blown to smithereens also! I think the Zeus was in a potted case too.
Even a Zeus can only handle so much energy.

TriX Loc: Raleigh, NC

Yep, it was a freak failure, but ultra scary. One Sunday morning a loud bang and bright flash outside the house, all the lights went ultra bright and then started blowing out and smoke was literally coming out of multiple devices and outlets in the house. I ran to the basement and pulled the main breaker just as the event ended when the drop burned in to. If I use that whole house suppressor in the future, it will be in a metal enclosure. The power company’s insurance company paid for all the fried devices (4K$), and it was lucky it didn’t burn down the house.

TriX Loc: Raleigh, NC

Yep, I have a ham radio station with a tower and multiple antennas, and there are gas discharge suppressors on ALL the coax and control lines as well and polyphasers on the VHF and UHF satellite antennas. Multiple 8’ Ground rods bonded to the house ground and the antenna coax connector panel with copper strap and a grounding antenna switch that grounds everything (radios and all antennas) when off. Even with the cone of protection it offers the house, I still pray I never have a direct hit, because all that will likely vaporize. When I was at our local hospital recently, I noted lightning rods and heavy flat braided cable connecting them to ground all over the hospital roof (Flat conductors are preferable to round wire because of the lower inductance at high currents).

Edit: I didn’t know they were using gas discharge tubes in whole house suppressors - I wonder whether the Zap Cap is gas discharge or MOVs? Do you know?

ad9mac

Are these any use against EMP?

TriX Loc: Raleigh, NC

Good question - I doubt it, will have to research that. Depends on how close you are to the blast. The issue is the EMP pulse is very fast and powerful and every wire and circuit trace in an electronic device acts like an antenna, so you may protect the power line, but the wiring and board traces inside the device picks up the pulse and kills semiconductor junctions. Odds are, the only thing that will work afterwards are vacuum tubes. There was a standing joke in the past that in the event of a nuclear detonation, only the Soviets would still have working radios, because they were still using vacuum tubes

Longshadow Loc: Audubon, PA, United States

No, I do not.

Longshadow Loc: Audubon, PA, United States

No, the EMP is in the air and affects all electronics.
It will kill battery operated devices also. Like your car.
(Not sure if an un-powered device is affected though.)
It does not come down the power line, per se, but will have effects on the power distribution system.

ad9mac

Thanks

Longshadow Loc: Audubon, PA, United States

BTW - You cant see, hear, feel, smell, or taste an EMP.
Electronics will simply quit working when exposed to one with enough energy.