I want to verify if electricity outlet is grounded. For this I did a test using a bulb connecting it to Phase and Neutral and it lit (to verify if bulb works). Then connected with Phase and Ground and the bulb lit up again. As I still doubted it, I found out where the grounding rod is installed and removed the cable connecting it to the mains (at the grounding rod). Then did the same test and found out that the bulb still lights up. My understanding on this is ... either there is another grounding point or the Neutral is connected to the Ground plug point. Am I correct? How can I verify if the Ground cable is connected to Neutral cable? Thanks
In Canada (and probably US) the Neutral and house Ground are connected in the main breaker panel, and that point is connected to a earth ground rod nearby. The power company also connects the Neutral to an earth ground at each distribution transformer. The specifics of Earth ground and Neutral/Ground connections may vary in different jurisdictions.
Further to what Peter Bennett says above, here in the UK the two main systems are TNS and TNCS as we call them. TNS is a system in which Earth and Neutral are supplied to the consumer via separate conductors, whereas in TNCS they are combined as one conductor as far as the consumer unit and then separate after it. So it depends what you have. The Earthing rod in your installation is probably there not as the Earth path, but to, er, Earth the earth, which ensures that the local Earth (literally, the earth) is at the same potential as the common Earth of the electrical distribution system.
So it's unlikely that disconnecting the Earth rod will disconnect your Earth from the Neutral, since they are connected either at the incoming service head or at the supply company's transformer.
It is common to see improper residential upgrades even in advanced urban areas like Toronto. done improperly, by immigrant trades people with no professional training, just trying to make a living.
In my previous home the previous owners had contractors upgrade the house with 50 ceiling pot-lights on all floors and when I went to add a 2 way stair/hallway switch, I found they mis-wired it and I had bulb current glowing thru the safety ground in the attic and in wall switch.
You are doing a good test but trace it back to the breaker panel and check earth water mains copper for a ground reference with a Voltmeter.
There is an allowance of 5% of Vac for line voltage on neutral from conduction loss and ground resistance can be as high as 100 Ohms or so at the pole in dry areas in dry weather.
Check your breaker panel to sub-ground water plumbing then check
- L1 to N
- L2 to N then
- N to Gnd in different places with load ON.
A $10 DMM is a good investment if you don't have one.