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05-23-2013, 07:54 PM #1
Point of entry (aka whole house) surge protection recommendations
I am wanting to install a point of entry surge protection at my main service panel. With the cost of appliances, electronics, and the vfd's recenty installed, I need to get this done. Any recommendations, experiences or advice? Thanks!
05-23-2013, 08:22 PM #2
05-25-2013, 03:11 PM #3
Exactly what is your main panel? Square D QO or Homeline, Cutler Hammer CH or BR, Siemens etc.
Many manufacturers produce compatible products like the one listed above.
Another big consideration may be the insurance and warranty offered with the device. But with that I would go with a known company not the new kid on the block as they may be gone tomorrow along with your insurance and warranty.
Along with the SPDs you need to make sure you have a solid and effective grounding system for them to work with.
05-25-2013, 03:18 PM #4
I know this as helpful as T^$s on bull but there is a unit(s) available that will cover power, cable and a land line(s) if you still have one. I just can't remember the manufacturer, but I'm sure a little time google and you will find it. Sit down first if they list the price though.
05-25-2013, 03:33 PM #5
Part of the reason for this thread is to find what others have experience with. Having looked online, the choices are many. My service entrance is a fused disconnect, than to a 200amp transfer switch for the backup generator, than the line is split between the house and shop to their panals. So a unit that could mount at the transfer switch would be ideal as it would cover both the house and shop, and the ground rod is only 3ft away. Leviton and Eaton are a couple of choices I have seen, but are more or less disposable if an event faults them out. Like I said, so many choices.
05-25-2013, 04:35 PM #6
I have an Intermatic on my house a Square D QO on my shop and have installed a number of SPDs that most smaller shops would never be willing to spend the $ on.
No one can give you a 100% guarantee that their device will save your equipment period.
That is why I mention the $ insurance offered by the manufacturer.
My SPDs have worked fine to the best of my knowledge but I do not know for sure weather I have had any major spikes.
I have a customer that did have a confirmed major spike that only tripped one GFI outlet and nothing more, their only protection was the extensive grounding grid I installed for their future lightning protection system.
A single ground rod is a very poor grounding electrode system.
Ground rods are often a steel core that rots away gaining higher resistance over time, galvanized rods are the worst, copper clad much better and Stainless the best.
A good grounding electrode system uses all possible electrodes, metal water pipes, concrete encased metal, building steel ground rings etc.
All SPDs are actually disposable, they may all sacrifice themselves to save your equipment.
Most good ones will have some type of indicator lamps on them.
Personally I would install one at the main service and one in the out building, which is how my house is set up.
I would also make very sure that 1 ground rod is not the only piece of your grounding electrode system.
How much are you willing to spend?
How much $ in equipment do you want to protect?
05-25-2013, 08:34 PM #7
A properly designed system (with UPS installed) can take a lightning strike, blow the meter off the outside of the building, and the call center employees won't be aware of what happened.
Copper.org: Innovations: Florida Credit Union Data Center Shrugs Off Direct Lightning Hit
But no matter what the cost, the investment in a little extra copper paid off handsomely for Suncoast on the day the lightning struck….
...And No One Noticed!
Earl Brendle, Suncoast's vice president, facilities, was working in one of the bank's branches when he got a call from the data center. As Brendle recalls, "The data center has a 250-kW emergency generator and transfer switch to keep us on line whenever we lose utility power for extended periods. Last year, one of the center's technicians stepped outside about half an hour after a storm passed and noticed that the generator was running, and would I please stop by to reset it.
"When I got to the data center, the generator was still powering the building. That seemed odd, because if the generator had kicked in due to an outage, it should have shut down once utility power was restored.
"Then I saw the meter, or rather, the mass of burned metal and insulation that was left of the meter socket (Figure 2). Lightning had struck our 480-V service entrance cable. It blew the meter off the wall (we never did find it) and headed straight for the transfer switch and generator.
05-26-2013, 08:39 AM #8
The data center story is interesting, will somebody now excavate the grounding system to ensure integrity?
05-26-2013, 10:02 AM #9
06-02-2013, 12:30 AM #10
I have Cutler Hammer CH series panels at my place and run the Cutler Hammer brand stab in surge suppressor in all of them. They snap in, occupy the place of a two pole breaker and don't hog up space like some surge units. There are LED lights on them so you can check their health, and have a moderate joule rating.
A surge suppressor does not protect you from everything. It does not protect you from sustained overvoltage. An example of that would be that the distribution circuit your place is fed by is most likely 12,470 volts line to line. If your circuit is "underbuilt" under a transmission line, say 69,000 volts line to line, and some tree knocks down one of wires energized at 69,000 volts down and it makes contact with the underbuilt 12kV line presto you have sustained over voltage at your place that is nearly 6 times your normal voltage of 120/240V. The utility cries act of nature and you get stuck with the bill to repair all your fried equipment. As far as I know any commonly available surge suppressor cannot protect against sustained over voltage. Lighting yes... Sustained no.
They also do not protect from brown out conditions or open neutral problems.
One of the best things you can do is make sure you have a good ground. Buy some #4 bare copper and a couple of 8' ground rods. Drive them in at least 6' apart and tie them to your ground bus bar. Cheap insurance if your service panel is older and the condition of the existing grounding system is unknown.
Beyond that they are all similar. They all have metal oxide varistors inside. The higher the joule rating the better the unit is (and more expensive). The MOV's provide very high resistance from the energized wires to ground at normal voltages, but when the voltage spikes they provide a low resistance path to ground. They can withstand this for a very short time.