Connected a PC to an outlet lacking a ground connection...
Connected a PC to an outlet lacking a ground connection...
You face multiple challenges here, beginning with the obvious lack of a dependable Ground in your new apartment. A Ground serves two main roles: it protects wiring and circuits from accidentally sending real power to accessible areas, and it helps eliminate static charges and electrical noise at low levels before they escalate into bigger issues.
1. Imagine there is no Ground anywhere. Even the three-prong outlet you possess might have been installed correctly, but this is unlikely. It's a common mistake to switch from a two-prong to a three-prong plug on an ungrounded system simply to allow use, without actually establishing a proper Ground connection. Unless you can confirm the three-prong setup is correct, it’s probably not.
2. Consider how 110 VAC house wiring in Canada and the USA functions. It relies on a Grounded Neutral system. At the transformer on the power pole and in the fuse or breaker box at home, the Neutral line connects to a real earth ground. Thus, at these points, the Neutral is at zero potential relative to the earth. Elsewhere in the house, the Neutral isn’t guaranteed to match the earth potential. It carries current back to the Neutral bus in the fuse box. Because wall wiring has minimal resistance, a slight voltage exists at the outlet on the Neutral line compared to true Ground.
3. In the house’s fuse box or breaker panel, there is a genuine Ground connection to the panel itself. This connects to the Neutral bus inside the box. Modern designs often feature a dedicated Ground bus, with wiring using insulated cables for two current-carrying conductors plus a bare copper wire for Ground. This ensures Ground is provided at every outlet. Importantly, nothing (except the Ground lead) should connect to this Ground, keeping it free of current under normal conditions. Older systems lacked a Ground lead beyond the main panel and didn’t have a dedicated Ground bus.
4. Today’s three-prong outlets use cables with three wires—labeled 14/2 for hot, two insulated conductors, and a bare Ground wire. The color code is: black for Hot, white for Neutral, and bare for Ground. When a 3-prong outlet is installed in the wall box with the bottom hole aligned to a downward-pointing triangle, the bottom (Ground), left (Neutral), and right (Hot) terminals are clearly defined. This prevents incorrect plugging, as a polarized plug won’t fit due to size differences. In older non-Grounded setups, there was no Ground lead beyond the main panel, and no dedicated Ground bus.
5. Modern systems with 3-prong outlets include a cable in the wall box with three wires—black (hot), white (neutral), and bare (Ground). Using a neon tester, you can detect 110 VAC from Hot to Neutral and also from Hot to Ground, but not from Neutral to Ground. This is because small voltages between Neutral and Ground aren’t visible. In older ungrounded systems, you might still see 110 VAC from Hot to Neutral, but no voltage appears between the Neutral and Ground connections in the wall box. This indicates the metal enclosure isn’t grounded.
6. To address low-level voltages or noise, consider connecting a separate green Ground wire from your computer case to a reliable Ground source—ideally a water pipe. Older systems with all metal piping work well, but some modifications with plastic components can compromise reliability. This remains your most viable option.
7. Another critical function of a proper Ground is safety in electrical supply systems. A Grounded system ensures that any exposed appliance part is connected to true Ground. If a fault occurs and hot power contacts the exterior, the Ground provides a high-capacity path for current to flow to Ground—exceeding the fuse or breaker’s rating, thereby interrupting the circuit. Simultaneously, during the brief moment this happens, touching the exterior remains near zero volts, reducing shock risk. Installing a green grounding wire to a nearby water tap may help carry minor currents and provide some protection, though its effectiveness depends on the quality of the connection. It won’t eliminate electrical noise or static charges but can enhance safety.
8. As an alternative to a traditional Ground system for safety, consider a Ground Fault Circuit Interrupter (GFCI). These devices are available in various configurations and resemble standard 3-prong outlets. They monitor current flow between Hot and Neutral; if a discrepancy is detected, they trip the circuit, preventing dangerous currents. Unlike a real Ground, they don’t require physical earth connection but still offer robust protection against shocks and appliance faults. Once installed, they provide automatic shutdown via a TEST and RESET button, alerting you to issues without needing a ground connection. They work in ungrounded outlets too, as long as proper installation is done by a qualified electrician.
9. After resolving the underlying wiring problems, using a GFCI for safety and a green Ground wire for static charge removal can be effective solutions. These options address both electrical noise and shock risks, though they don’t eliminate surges or static buildup entirely. For optimal protection, combining these two measures is often the best approach.
I found the page you mentioned and would like to share it. Please copy it here or paste the link, and I’ll add it to your troubleshooting guide. Let me know if you need any adjustments.
Thank you Paperdoc. As mentioned before, your post was very useful. I appreciate your handling of the issues beyond power surges.
I have a follow-up question. Following advice from others, if I were to connect a 2 prong to 3 prong adapter with a ground tab (like this one), and connect a wire from the screw to a water pipe, would that offer the same protection? Or would it be better to run a wire directly from the case to the pipes?
My goal is to use a surge protector strip for powering my computer. Grounding it at the outlet would seem ideal, at least.
Thank you again,
Ryan
Measurements:
Appreciate Paperdoc. As mentioned by those before me, your message was quite useful. I’m particularly grateful for how you addressed the issues beyond power surges.
I have a follow-up concern. As others have suggested in their replies, if I were to connect a 2-prong to a 3-prong adapter with a ground tab (such as this one), and connect a wire from the screw to a water pipe, would that offer the same level of protection? Or would it be better to run a wire directly from the case to the pipes? My question stems from wanting to use a surge protector strip to power the computer. Ideally, I’d like to ground it at the outlet, which seems like a more reliable approach.
Thank you very much,
Ryan
I got my 500watt BOSCA dc to ac inverter... pc/moniotor/modem running without problems for two hours. But I think I have not enough solar power reaching my MPPT to match the 200-250 watts I’m drawing. That’s why I ordered an extra 300watt solar panel, even though its size suggests it shouldn’t exceed 50 watts. I wonder if China is really that far ahead of the game.
This inverter has a fan at the back, so it doesn’t get too hot to touch.
A silly question though... if most or all inverters have a grounding slot, where exactly is it? There’s very little contact between my solar setup and the ground floor...