400 ampere service is an indicator of your electrical panel’s capacity. The 400 ampere service electrical panel is one of the strongest panels in the world. The extra load of current can be handled by installing a 400 amp service.
Today, we are going to discuss and find out about what size ground conductor and wire are needed for 400 amp service.
Ground size for 400 amp service
Different sizes of ground wires and ground conductors are needed for a 400 amp service panel. 3 AWG ground wires and conductors are required for copper grounding. However, 1 AWG ground wires and conductors are sufficient for aluminum grounding. 1/0 is the ground size needed for bare ground.
Table of Contents
Let’s look at different kinds of ground conductors and find out the required size for 400 amp service.
Bare/Earth ground:
Bare or earth ground conductor is an important part of a 400 amp service installation process. Bare ground conductor provides protection to your electrical panel while installing the powerful 400 amp service.
The size of the bare ground conductor when it comes to installing a 400 amp service is considered to be 1/0. This size of bare ground conductor is approved by many different building and electrical codes.
Aluminum ground:
The highly powered service panel will require a slightly lower size aluminum ground conductor. For example, a 6 AWG size aluminum ground conductor does the trick for a 100 amp service panel. But it will not be sufficient enough for a 400 amp service panel.
There are many things that you will need to take into consideration before installing a 400 amp service panel.
It is believed by electrical experts that a 1 AWG size aluminum ground conductor will do the trick for a 400 amp service panel. Using the proper size of aluminum ground conductor is key to the successful installation of a 400 amp electrical service panel.
Equipment ground:
The aluminum ground conductor and the copper ground conductor are parts of the equipment ground procedure. The amalgamation of these two grounding conductors make up most of the equipment ground.
A 3 AWG size grounding conductor is perfect for copper grounding. But a 1 AWG size grounding conductor will be required for the aluminum grounding conductor.
Ufer ground:
Ufer grounding conductor is not a common feature of a 400 amp service panel. However, there are some instances where ufer grounding has been used in 400 amp service panels. Keeping this in mind, we need to focus on the size of the ufer ground conductor.
The required size for a ufer ground in a 400 amp electrical service panel is said to be 1/0 size. No other size of ufer conductor will be suitable for a 400 amp electrical service panel.
Copper ground:
According to electrical experts, copper ground is a crucial part of your 400 amp service panel. If you use the wrong size of copper ground conductor in the 400 amp service, then it can really mess up the procedure.
The 3 AWG size copper ground conductor has been suggested by experts all over the world.
You can seek the help of a professional electrician if you are still confused about the size of your copper ground conductor. You should not begin installing the 400 amp electrical service panel without adequate information and experience.
Water ground:
Copper or aluminum ground conductors are used as water ground conductors. In this case, 3 AWG size copper ground conductors have to be used as water ground. On the other hand, 1 AWG size aluminum ground conductor should be sufficient.
Water ground conductor is one of the least important parts of a 400 amp service panel. But every ground conductor of the 400 amp service panel matters in the grand scheme of things.
What size ground wire for 400 amp 3 phase service: NEC Code
The code provided by the NEC (National Electrical Code) is important when it comes to installing a 400 amp 3 phase service panel. NEC also provides codes about the size of the ground wire needed for installing the 400 amp service panel.
The NEC code specifically focuses on the size of the copper ground wire and aluminum ground wire in terms of installing the 400 amp 3 phase service panel properly. First of all, NEC states that you will need a lower gauge wire for a higher capacity service panel.
That is why NEC codes recommend 3 AWG or kcmil ground wire size for copper ground wire. The 3 AWG grounding wire will be more than enough at handling the load of the 400 amp 3 phase service panel.
On the other hand, NEC codes suggest even lower gauge wire for aluminum ground wire. They recommend the usage of 1 AWG or kcmil ground wire for aluminum grounding in a 400 amp service panel.
Selecting the accurate ground wire size is crucial and professional help should be sought in this matter.
How do you size an equipment ground for 400 amps?
Sizing an equipment ground for a 400 amp service panel might seem like a difficult task without prior experience regarding the matter. However, there are some steps and methods you can follow to complete the task. Let’s discuss in detail about some of them.
Follow the NEC codes:
First of all, you will need to follow the instructions provided by National Electrical Code regarding the installation of a 400 amp service panel. NEC has made these codes after taking all the things into consideration.
These codes created by NEC are based on safety, security and practicality.
Following the NEC codes in order to size an equipment ground for a 400 amp service panel is a good method. You will need to find out what the NEC codes say about different grounding required for the equipment ground.
Follow the local building codes:
Following the local building codes is also a proven method of sizing an equipment ground for a 400 amp service panel. Most of the time, the local building codes follow the codes provided by NEC. However, the local building codes can sometimes differ from NEC codes.
That is why following the local building codes while installing the 400 amp service panel is important. Otherwise, it can land you in legal trouble with the local authority.
Seek professional help:
If you have no prior experience of working on an electrical service panel, then sizing an equipment ground can be a hard job to do. That is why professional help should be sought in this matter.
A professional electrician will be able to size an equipment ground accurately because of his vast experience.
Installing a 400 amp service panel on your own can do you more harm than good. Getting it done by a professional might cost you some extra money. But it will be more durable and beneficial in the long run.
How do you wire a 400 amp base?
Wiring a 400 amp base might feel like a difficult job due to lack of experience. But there are some steps and methods you can follow to implement the task effectively. Let’s discuss in detail about some of them.
Gather the equipment and tools:
First of all, you will need to gather all the required equipment and tools for the wiring process.
The list of equipment and tools includes copper wires, aluminum wires, a voltage tester, a wire stripper, a screwdriver, a cable ripper, electrical tape etc. You will be good to go after gathering all of these tools and equipment.
Inspect the feeder wires:
The feeder wires coming from the street will have to be inspected for power. You will need to use the voltage tester to ensure there is no electricity coming in from the feeder wires. Otherwise, it could cause unwanted accidents.
Hang the 400 amp service panel:
In the next step, you will need to hang the 400 amp service panel at the appropriate spot. You will need to drill holes into the wall and use screws to attach the 400 amp service panel onto the wall. This is a very crucial step for the overall success of the process.
A poorly hanged 400 amp service panel will cause problems in the future.
Attach the grounding wires:
You will be required to attach the grounding wires to the 400 amp service panel in this step. The list of grounding wires will include bare ground, copper ground, aluminum ground, ufer ground, equipment ground, and water ground.
You will need to follow the wiring diagram provided by the NEC to complete the wiring process. The NEC even specifies the size of the grounding wires required for a 400 amp service panel.
Final Thoughts
Selecting the accurate ground size is important for the installation of a 400 amp service panel. The NEC comes in handy in this case as they provide the appropriate grounding size required for a 400 amp service panel which can be of 1 awg to 3 awg. An electrician will be able to choose properly.