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Answer for USA, Canada and countries running a 60 Hz supply service.
Yes, you have to have a ground rods connected to the system. This is especially important in North American systems as a split phase is in use. The center-point winding by code must be grounded. This is a backup in case the neutral conductor becomes open. If this backup was not in place, due to the configuration of the distribution panel, 240 volts could be applied across two 120 volt loads which would be a series connection. If the resistance across both of these series loads is equal nothing will happen as the voltage drop would be even at 120 volts. If the series load resistances are not even then uneven voltage drops will appear. This could cause higher that allowed current to flow through devices that would damage them. Periodic maintenance of the ground rod connections should be done by every homeowner to make sure the connections are clean and tight.
Wiki User
∙ 12y ago
Wiki User
∙ 13y agoThere should be a ground between the sub panel and the main panel, but DO NOT bond neutral to ground at the sub panel, only at the main panel. There should be a screw or metal strap that does the bonding.
Wiki User
∙ 14y agoYes, if the sub panel has more that two circuits from it and is not part of the original building that houses the main distribution panel.
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What do you need and how can you install a ground cable if your 240V outlet doesn't have a ground wire?
You need a 3 conductor wire with ground. For example if you had a 30 amp breaker for that outlet you would need 10awg 3w/ground. That's 10 gauge 3 conductor with ground and replace the old wire back to the panel.
Why would you have 115 vac on your neutral bus in the panel that has a separate ground buss?
Certainly your neutral bus is not properly bonded to the ground buss and grounding electrode conductor. But the size of your voltage worries me. You need a competent electrician to check this one for you.
What should the clearance be from service entrance panel to grounding material?
grounding material is not a good word but as short as possible is a good answer the entrance panel must be connected to the best possible ground this is called the grounding electrode the grounding electrode conductor connects to the ground bar in the entrance panel if the panel has a a neutral the neutral bar can be bonded to the ground bar Grounding electrodes form best to worse well casing water pipe (NOT plastic) buried plates or wire grid or bonded reinforcing steel driven rod if you are talking about distances to the panel it should be centered about shoulder height doors need to have about 2' of clearance in all directions weather open or shut
How would you extend underground wire to your panel currently aluminum wire run to panel about 300ft I need to extend this to a new shop with a 100 amp panel 50 extra feet?
This is not a job for an amateur, but I will help you with some primary considerations. My answers are based on the United States' NEC (code) and do not take into consideration any local requirements. You do not want to extend your existing service conductors. You want to install a 100amp breaker into your existing panel and run conductors from there to your new panel. If this is a residential application you can run this with #4 copper conductors. If this is a commercial application you must run #3 copper conductors. I would answer this question based on what your shop is intended to do. If you are running professional equipment and are more or less "in business", use the commercial requirements. If you know how to properly ground a new service, and if your new panel has a main breaker, you can do what you need with 3 conductors. This will allow you to put neutral and ground conductors on the ground bar like you would in your primary panel. If you do not know how to properly ground a new service or doing so is not practical, you will need 4 conductors and your grounds and neutrals will have to be ISOLATED from each other in the new panel. Your neutral bar in this case would be insulated from the panel. In this case your new panel would become a sub-panel of the primary panel. Some panels do not have a main breaker and this is a critical consideration if you intend to wire it as a new service. Personally, I wouldn't install a panel without a main breaker whether or not it is a service or sub-panel.
Does the ground wire on a 200 amp panel need to be looped through both ground rods?
Not looped but connected to both ground rods and then connected to the meter base.
What do you need and how can you install a ground cable if your 240V outlet doesn't have a ground wire?
You need a 3 conductor wire with ground. For example if you had a 30 amp breaker for that outlet you would need 10awg 3w/ground. That's 10 gauge 3 conductor with ground and replace the old wire back to the panel.
How do you make floating ground in 100 amp sub panel Sub panel 30' from main panel and is grded to 2nd 10' rod wired to 1st 10' rod at the main panel. GFCI bkrs are nuisance tripping in bsmt location?
If the sub panel is in the same building remove the bonding screw that bonds the neutral bar to the panels enclosure. Remove the ground from the second ground rod. The sub panel is grounded by the ground wire from the sub panel's feeder. If the panel is separate from the main building treat the sub panel as a separate service. It will need its own ground rods and ground wire from the rods to the neutral bar of the sub panel. Leave the bonding screw in. There will be no ground wire in the conduit between the two services.
Why would you have 115 vac on my neutral bus in the panel that has a separate ground buss?
Certainly your neutral bus is not properly bonded to the ground buss and grounding electrode conductor. But the size of your voltage worries me. You need a competent electrician to check this one for you.
Why would you have 115 vac on your neutral bus in the panel that has a separate ground buss?
Certainly your neutral bus is not properly bonded to the ground buss and grounding electrode conductor. But the size of your voltage worries me. You need a competent electrician to check this one for you.
What wire size do you need for a 125 amp panel with a 100 amp main breaker?
A #3 copper conductor with an insulation factor of 90 degrees C is rated at 115 amps. Even though the panel is rated at a higher amperage it is the main breaker that governs the wire size.
Where do you ground on 100 amp panel?
A typical panel has three large wires entering the main panel from the electric meter and a bare ground wire. Two of the large wires are hot and go to the busses where the breakers are mounted. The third wire is common and is connected to one or more common bus locations. It will usually be silver in color with a screw on top to connect white wires from branch circuits. The ground is the metal of the panel itself and there will be one or more ground busses usually copper colored that are connected to the metal of the panel by screws there by "bonding" these ground busses to the metal of the panel. You should also see a copper wire coming from a ground rod connected to the metal of the panel. At the main panel you need to bond the common to the ground. There is usually a screw that allows this bonding to occur. If you have subpanels ground and common are NOT connected at the subpanels.
Do you need a grounding rod at a subpanel on a detached building?
Yes. The panel must be grounded with its own grounding rod. The ground will not be provided with the feeders to the panel, these will only contain your phase wires and neutral. Also make sure that any subpanel installed does not have the neutral bonded to ground. This should only be done at the main panel where the electrical utility service is connected.
Is the voltage on a 120 volt fluorescent lighting circuit the same from line to neutral and line to ground?
Yes, to the precision you can measure it. If it isn't you need to check the ground to neutral bonding at main panel and check the wiring in the circuit for loose connections.
What should the clearance be from service entrance panel to grounding material?
grounding material is not a good word but as short as possible is a good answer the entrance panel must be connected to the best possible ground this is called the grounding electrode the grounding electrode conductor connects to the ground bar in the entrance panel if the panel has a a neutral the neutral bar can be bonded to the ground bar Grounding electrodes form best to worse well casing water pipe (NOT plastic) buried plates or wire grid or bonded reinforcing steel driven rod if you are talking about distances to the panel it should be centered about shoulder height doors need to have about 2' of clearance in all directions weather open or shut
How would you extend underground wire to your panel currently aluminum wire run to panel about 300ft I need to extend this to a new shop with a 100 amp panel 50 extra feet?
This is not a job for an amateur, but I will help you with some primary considerations. My answers are based on the United States' NEC (code) and do not take into consideration any local requirements. You do not want to extend your existing service conductors. You want to install a 100amp breaker into your existing panel and run conductors from there to your new panel. If this is a residential application you can run this with #4 copper conductors. If this is a commercial application you must run #3 copper conductors. I would answer this question based on what your shop is intended to do. If you are running professional equipment and are more or less "in business", use the commercial requirements. If you know how to properly ground a new service, and if your new panel has a main breaker, you can do what you need with 3 conductors. This will allow you to put neutral and ground conductors on the ground bar like you would in your primary panel. If you do not know how to properly ground a new service or doing so is not practical, you will need 4 conductors and your grounds and neutrals will have to be ISOLATED from each other in the new panel. Your neutral bar in this case would be insulated from the panel. In this case your new panel would become a sub-panel of the primary panel. Some panels do not have a main breaker and this is a critical consideration if you intend to wire it as a new service. Personally, I wouldn't install a panel without a main breaker whether or not it is a service or sub-panel.
Does the ground wire on a 200 amp panel need to be looped through both ground rods?
Not looped but connected to both ground rods and then connected to the meter base.
Can neutral and ground wires be connected to the same buss bar in a service panel?
No. The sub panel is wired that same as an ordinary three wire load. The three wire is connected the sub panels terminal points as red to L1, black to L2, white to the neutral bar and the ground wire in the cable set to the ground bar. The one thing that has to be done is the bonding screw that bonds the neutral bus to the panels metallic enclosure has to be removed. The electrical code states that there is only one place that the ground is joined to the neutral bar and that is at the service entrance point into the main distribution panel.
