We were on generator power last spring and using a small 3000 watt generator. My wife was using an expensive sewing machine and it fried the circuit board. I always wondered if it was because there was no ground.
No. But power quality could have been an issue.
jonyyuma, do you think using a good surge protector would protect a LCD tv while using a generator?
I used a generator a few years ago when our electricity was out and powered our old tv on it. But I'm kind of reluctant to try our new tv on one without some sort of protection.
It seems that a lot of things have some sort of computer or electronics on them anymore.
BTW, are you "panther quick and leather tough" as the song goes? :laughing:
A surge protector protects only against large voltage spikes. This was probably just an under-voltage/over-voltage condition which would not have mattered.
The ground the owners manual calls for is most likely for a case ground. Should the generator develop an internal fault it could hot up the generator case and frame and you could shock yourself by touching the unit if it was faulted so.
Its not needed for generation of power. It's an operator safety concern.
A portable generator has its neutral and ground bonded together. Should a fault develop, the breaker should trip.
For computers, TVs, and the delicate stuff its better to buy an inverter generator. When our power goes out the generator powers the two fridges, freezer, well pump, pellet stove, electric skillets, and some lights. No TVs, computers or delicate stuff. Ours isn't an inverter generator.
A true sine wave inverter generator is the best quality, a modified/square is not much different than a portable generator. But electronics like computers/TVs/etc. are not sensitive to their power input and are safe on just about any portable generator.
If you want your UPS or line conditioner to be fully functional, you MUST have a good ground. --> Ground Rod
The more expensive UPS will have indicator lights or status displays for ground faults.
A UPS, power conditioner, etc. does not need the ground for working in any manner other than the safety it provides.
The purpose of the ground rod is to prevent there from being any difference in potential between the grounded generator output conductors and the Earth ground. Typically the grounded generator conductor is also bonded to the generator frame. That being the case, if your alternator had some problem in the windings and the genset frame was not connected to the Earth ground by a grounding electrode of some type you might see a higher voltage between an ungrounded generator output conductor and the Earth ground than between an ungrounded generator output conductor and the grounded generator output conductor. The difference in potential would be realized when you touch the generator frame with your bare hand while touching the Earth with your feet. You would become a better path to ground.....zzzzt. If you drive a ground rod and connect it to the genset frame that is already connected to the grounded generator output conductor you have bonded the frame to the Earth so there can exist no difference in potential between them. I am not an engineer but I cannot see this having any effect on breaker or ground-fault circuit interrupting devices. The breakers are tripping based on instantaneous or long term current wherever it goes and the GFCID's are measuring how much current goes out from the ungrounded conductor and how much comes back in on the grounded conductor and tripping when the difference reaches a setpoint of x milliamps. Remember the ungrounded conductor is the hot one, the grounded conductor is the return and the grounding conductor is used to bond conductive materials to the grounded conductor at the electrical service entrance to prevent your stove or dryer or refrigerator shell etc from becoming energized due to an ungrounded conductor coming into contact with it. If contact is made a short-circuit will result in a blown fuse or tripped breaker instead of the metal shell setting there energized and waiting for you to complete the circuit by touching it with one hand while your bare feet are on your concrete floor. Gotta Love it!
There's a ton of mis-information and confusion about what the ground rods in a home actually do and their primary purpose. The grounding conductors up to the main panel (or meter base, generator or wherever the ground and neutral bond exists) are for clearing shorts, typically with metal appliances. If the neutral and ground are bonded and the case of the appliance becomes hot due to an internal short, the current travels back on the ground conductor (otherwise unused) and trips the breaker. A connection to EARTH ground would be of too high resistance to clear these faults.
GFI/GFCI devices as you said do NOT need the ground to operate whatsoever. This is one of the reason they are used to add safety to older 2-wire receptacle locations without grounds present. Without the ground, your washing machine housing could become and remain electrified, however plugged into a GFCI receptacle (despite having NO ground connection) when you touched the machine, the current would be interrupted in time by the ground fault (the fact that current is traveling through you and returning somewhere else other than the neutral) before damage was done.
Past the ground/neutral bonding, the ground rods themselves are NOT to equalize voltage potential, return current via the earth or anything else.
Their primary purpose is lightning dissipation. WITH a ground rod and a fault with a portable generator, there is actually a higher risk for shock as it's introduced a new "hot" area immediately around the generator in addition to the frame, so ground rods are NOT required
nor recommended on portable generators with the neutral/ground bond in place (almost all of them). The NEC does not actually apply to portable generator use outside of where the NEC applies (when you connect it to a building, basically) but for personal protection the OSHA guide is a good reference.
In summary: for portable generator use (as a portable), it is not a safety advantage and maybe even a disadvantage to drive a ground rod. Do use the GFCI receptacles (required on generators that bond the neutral/ground and over 5kw anyway!) as they provide a large margin of added safety.
