When installing a panel, it is common to find two bus bars or screw terminals. When only one is present, it is for the ground wire only, while the other is for the neutral wire. The ground and neutral remain separate all the way back to the main panel if you have many panels.
Are Neutral and Ground Wires Together in the Main Panel
It’s not a good idea for neutrals and grounds to be together. This is something that a lot of electricians get wrong. That is now correct even in the NEC or The National Electrical Code. In every panel, there should always be a separate ground bar.
Only neutral wires must be in the neutral Bar and ground wires in the ground Bar. As a result, wires should never be bundled together in a panel. If a panel contains only one bus bar, the ground and neutral bars are joined together with a bonding jumper at the service entrance, which is the first panel encountered by electricity as it comes in.
It is to carry the neutral current down to the system ground and ensure that electricity wants to glide from the hot through the load and back through the neutral. After the electricity has been restored to the panel, it is routed from neutral to ground, and ultimately out into the Earth.
Bonding Neutral and Ground Wire
During normal operation, we want all neutral currents to return to the source transformer on the neutral wires, not on the ground wires, in a correctly built circuit.
A correctly built circuit will also contain a ground wire with a low impedance path back to the transformer during an electrical fault to guarantee that enough current flows to swiftly trip the circuit breaker.
The Purpose
For budgetary reasons, we sometimes bond the neutral and ground wires in the main panel. Installing a jumper wire is often less expensive than running a ground wire all the way from the transformer to the panel.
We must allocate the role of the fault current path to the neutral wire via a bond in the electrical panel when we do not pull a ground wire from the transformer to the panel. As a result, the neutral conductor from the panel to the transformer now meets the requirements.
The neutral and grounding wires are connected at the main service panel and to a grounding electrode, such as a metal ground rod, which is there to handle anomalous energy pulses, such as a lightning strike. The neutral is solely connected to the ground at this stage.
Separating Neutrals and Grounds
If the neutral and grounding wires are linked anywhere else other than the main panel, the return current intended for the neutral will flow back to the panel through both the neutral and ground wires.
This is dangerous for several reasons, the most important of which is that if the grounding wire and the neutral wire have a poor connection or break, the parts of the grounding system on the other side of the break will be energized, posing a shock hazard.
When both panels are in the same building, the National Electrical Code (NEC) requires independent neutrals and grounding wires in a subpanel, as well as separate neutral and grounding conductors back to the main panel.
Conclusion
In conclusion, ground and neutral wires should only be connected where the last point disconnects. And the last point of disconnect is the main panels only, not a subpanel. Connecting them in a subpanel can result in delivering some of the power back to the main panel, which is a bad thing. So, even though you should use a separate grounding bar in all the panels, you should only connect them in the main panel.
please i want more from neutral bar connected to earth bar and then we can only connected only in neutral to load or both to load . still confuse here.
all load can have head wires or not
please i want how schemedic diagram from switch to load please
thanks
In a basic electrical setup, the neutral bar connects to the neutral wire while the earth bar connects to the ground for safety. Loads typically connect to both the hot and neutral wires to complete the circuit. A schematic from switch to load involves the source providing power to the switch via a hot wire, then connecting the load to both the hot and neutral wires. Proper grounding is essential for safety. If uncertain, consult a professional electrician.
When I install a sub panel at the garage
I must seperste neutrals and grounds?
All grounds are bonded to the box?
Ground from main box needs to be conected to ground bar above?
And two copper ground bars driven into earth need to be connected to ground bus as well?
Yes, when installing a sub panel in your garage, it’s essential to separate neutrals and grounds. All grounds should be bonded to the subpanel’s metal box. The ground wire from the main box should indeed be connected to the ground bar in the subpanel. Additionally, connecting the two copper ground bars driven into the earth to the ground bus in the subpanel is a good practice to ensure proper grounding and electrical safety.
A follow-up question here. My detached garage has a subpanel (old fuse box install from ~1950). There is *no ground* running from the main box in the house. Can I ground and bond the subpanel using ground bars driven in the earth, rather than run a new line with ground from the main (140′ from house)?
Using ground rods in the earth for your detached garage’s electrical panel is okay, but it’s not the best way. It’s safer to run a special ground wire from your main house panel to the garage panel, especially if it’s far away. This is because it provides a more reliable and safer path for electrical issues. Safety should always come first with electricity.