A 320 amp service is a residential service used for houses with multiple electrical devices. Besides, the service is also cheaper than the 400 amp service. But can you run it with 2 200 amps like in the 400 amps? Let’s figure it out.
You can run a 320 amp service with 2 200 amp panels. It has to be either two separate disconnects or a sub-panel with one main disconnect. Running with a sub-panel is cheaper than using two separate disconnects.
The 320 amps is a service ideal for residential 400 amp meter sockets. This article will explain the possibility and ways of running a 320 amp service with two separate panels.
What is the difference between 320 amps and 400 amps?
There is not much difference between the two amps.
A 320 amp meter base is rated for 400 amps non-continuous and 320 amps continuous load.
320 amp service is continuous, and a residential 400 amp service.
320 amp service is considered a new residential service, but sometimes a 400 amp service is called 320 amps by following the 80%.
In some areas, people do not have 320 amps. It is only 400 amps.
A 320 amp meter class is the largest read meter used in North America.
Once the meter is plugged into the meter socket, the current will pass through the meter.
The 320 amp is a single phase and contains 2 hot connections.
Both 320 and 400 amps can be used for large residential and small commercial services.
However, 320 amps are cheaper than 400 amps and thus preferred by most people.
Also read: Can You Run 400 Amp Service With 2 200 Amp Panels?
Can I run 320 amps with 2 200 amp panels?
Since there is not much difference between the two, you can run a 320 amp service using two panels.
When it comes to running the 320 amp service with two panels, you will have two options:
- Running 2 200 amp main disconnect panels
- Running one main 200 amp disconnect with a 200 amp sub panel.
Let’s discuss them in detail.
Running a 320 amp service with 2 200 amp main disconnect panels.
Since there is a huge increase in the usage of electrical appliances, people want a higher amp service to power their houses.
A 320 amp service will be a good continuous load residential service.
Since 320 amp is a huge and costly service, you may want to run it with 2 200 panels.
You can run the service with two separate 200 amp disconnect panels to receive 320 to 400 amp service.
You can add a new main panel if you want a new branch circuit.
But you must place it in a separate location, like a garage or workshop.
Both panels will require a power line from the electrical meter to the main panel.
In the local codes of your region, you need to have a meter base for a 2-lug design for installing 2 main disconnects.
A 2-lug meter base contains 2 hot and 2 neutral connections.
The setting will have 2 individual power lines to connect the meter base and meet the electrical codes.
Using two separate panels will give you 320 to 400 amps.
It is a great service for houses with separate pools, studios, workshops, rental houses, etc.
Though you can run a 320 amp with 2 main 200 amp disconnects, the cost will be huge.
Disconnect panels are more expensive than the sub panels.
Due to this, a maximum of experts recommend running one sub-panel with the main panel instead of 2 disconnects.
Due to the high cost, receiving approval for such settings also becomes important.
Running a 320 amp service with one main panel and one sub-panel
Since running a 320 amp with 2 200 amp main disconnect is expensive, adding a sub panel with a main 200 amp panel is another option for running a 320 amp service.
If you own a 200 amp main panel, install a 200 amp sub panel to run 320 amp continuous service.
Here, the cost charges will be much less than the 2 disconnect panels.
Generally, a sub-panel is installed when the main panel cannot handle the power used by the house.
Many house owners install sub-panels instead of upgrading their main service to a higher one.
It allows them to run a higher service with 2 panels without expensive charges.
To install a subpanel, one must have a main breaker inside the main service panel.
It will safely disconnect the electrical service from the other branch circuit of the house.
The sub-panel must be close to the main entrance panel or in a detached area, like a garage or workshop.
The sub-panel will feed from the main service panel.
The main disconnect will protect both the main and sub-panels.
Before installing a sub panel with a main disconnect, consider checking it with your area’s local codes.
Do not get worried just because it is a 200 amp sub panel.
A single 200 amp subpanel can feed about 3 more subpanels.
What factors should you consider while running 320 amps with 2 200 amp panels?
Whether you connect a main panel with a subpanel or two separate panels to run a 320 amp service, consider a few factors while running the service with such a setting.
What kind of power supply is required?
320 amp service is quite a huge service.
You will need a larger power supply to handle 320 amps with 2 200 amp panels.
For one 200 amp, you need a generator with 15 to 20kw.
It should produce around 15k to 20k watts of power.
For handling two 200 amp panels, you need a power supply double the size.
How to protect the circuit for such huge services?
It would be best to buy extensive and strong circuit breakers to run a 320 amp service with 2 200 amp services.
The breakers or fuses should be able to handle such high services and prevent damage from overloading and short circuits.
What size of wire is required?
For running a 320 amp service with 2 200 amp panels, you need thick wires to handle the current flow of the two panels.
#2/0 AWG copper wires will be the best choice if you use copper wires.
You can also go for #4/0 AWG aluminum or copper-clad wires, but since you will run 2 200 amp panels, it is best to use copper wires.
Use #6 AWG copper wires for the grounding connection.
320 amp is quite a huge service. It will be fine if you choose one 1-0 oversized wire.
The thicker the wire, the better the current flow and the lesser the chances of overheating.
Will there be a voltage drop?
Generally, there is always a voltage drop of 3% or 5%.
While running a 320 amp with two 200 amp panels, a voltage drop will occur, especially if the second panel is attached to a separate location like a garage or workshop.
Big distances and increased current flow can lead to greater voltage drop.
High voltage drops can cause issues in the performance of the appliances and power quality.
To keep the voltage drop from increasing, ensure the distance between the panels is not high and the cables are thicker.
How to ensure the current load remains balanced?
To run 320 amps, you will have two 200 amp breakers on every side of the panel frame.
Each panel should be fed with power from one leg of the 240V service given by the service panel.
You must check that the electrical service draws equal power from each 200 amp panel.
Otherwise, one panel will get overloaded while the other will remain unused. Overloading can damage the panel and cause short circuits.
For an observation of the load balance, ask your local electrician to give you a regular calculation of the balance.
If there is any problem, ask the professional to check and fix the problem.
Permits and inspections for running 320 amps with 2 200 amp panels
Since 320 amps is a huge service and you will be running it with two 200 amp panels, you should need permission for such a setting.
It is common for house owners to install a subpanel with the main panel.
The process is easy and cheaper than installing two main panels.
Connecting two main 200 amp disconnects is very costly.
Due to this, local electrical codes in some areas do not recommend using it. If you do, you may face issues in receiving permission from the region’s building department and local electrical codes.
The local contractors may not permit you to run two main disconnects in one structure.
Even if you receive permission, the inspection team from the building department will inspect frequently and ask for high expenses for installation.
However, the National Electric Code has permission for both settings.
But, if local codes are different, you won’t be allowed to follow the NEC code.
If you do such a setting, get permission from your local code before you start the project.
What safety measures should be taken?
Running 320 amps with 2 200 amp panels will require proper safety measures to avoid overloading and short circuits.
All the above factors discussed are the factors you must consider.
They are safety measures you should take to run a 320 amp with 2 200 amp panels.
Some major safety measures include:
- Using thicker wires
- Maintaining short distances between two panels.
- Making sure that power is equally drawn from both panels, especially in the case of the two disconnect panels.
- Take permission from the building department and local codes for such settings. They can suggest which setting is applicable in your area.
You can run 320 amps with 2 200 amp panels.
You can run it by installing 2 separate disconnects or 1 sub-panel with one main panel.
Contractors recommend running one 200 amp panel with one 200 amp main panel. It is cheaper than running two 200 amp main panels.
Due to the higher cost, contractors do not suggest running two disconnects in one structure.
However, you can run both if you get permission for it.
Since 320 amps is a huge service, you should follow certain factors and safety measures to run the panels safely.
Use thicker copper wires, reduce the distance, ensure that both panels’ loads are balanced, and use robust breakers to protect the electrical service.
What will using two main 200 amp disconnects for 320 amps cost?
The installation cost will be around $1,300 to $1,500, including the labor cost, breakers, wire price, and wiring per foot lineage.
Do I need a 320 amp?
If you have multiple electrical appliances with a detached structure, you will need a 320 amp service to support the appliances.
Data Source: National Electrical Code, NEC Wire Table, Electrical wiring, Home wiring.