How to Wire a 200 Amp Sub Panel

Installing a 200 amp sub panel in your home provides additional circuits to power more appliances and equipment. Wiring a sub panel properly ensures safe, reliable power distribution. This guide covers everything you need to know to wire a 200 amp sub panel correctly.

Selecting the Right Sub Panel

The first step is choosing the right 200 amp sub panel for your needs. Here are key factors to consider:

Selecting the optimal size sub panel with suitable specs prevents issues down the road.

Wiring the Sub Panel

With the right sub panel selected, you can move on to the wiring. Follow these key steps:

1. Turn Off Main Power

Shut off the main breaker in your main electrical panel. Verify power is off with a voltmeter before working.

2. Mount the Sub Panel

Mount the sub panel in the desired location securely. Leave at least 30 inches of space in front of it for access.

3. Run Conduit to the Sub Panel

Run rigid metal conduit or EMT conduit between the main and sub panel locations. Do not use flexible conduit or Romex cable.

4. Pull the Supply Wires

Pull the supply wires from the main panel through the conduit to the sub panel. Use THHN/THWN-2 insulated copper wire. Size according to the sub panel amperage - 200 amps requires 2/0 AWG wire.

5. Connect the Grounding Electrode Conductor

Connect a 6 AWG grounding electrode conductor from the sub panel ground bar to a grounding rod or other electrode.

6. Connect the Neutral and Ground Bars

Connect a 6 AWG bonding jumper between the neutral and ground bars in the sub panel. Keep them isolated in the main panel.

7. Attach the Supply Wires

Connect the supply ground wire to the ground bar in the sub panel. The neutral wire goes to the neutral bar, while the hot wires go to the main breaker or lugs.

8. Add Breakers and Connect Circuits

Install breakers for each new circuit. Connect the circuit wires to the appropriate breakers using 12 or 14 AWG THHN wire based on the amperage rating.

With the sub panel wired properly, restore main power and test operation of all circuits. The sub panel should now offer expanded capability to power additional appliances and equipment. Contact a qualified electrician if you have any doubts working with 200 amp electrical systems.

Sub Panel Grounding and Bonding

Proper grounding and bonding is critical for safety. Here are key grounding tips:

Maintaining separation of ground and neutral throughout the circuits avoids problems from stray current.

Common Sub Panel Mistakes

It's easy to make wiring errors that can create hazards when installing a sub panel. Watch out for these common mistakes:

Paying close attention to sub panel wiring best practices avoids these mistakes during the installation process.

Recommended Safety Tips

Working with 200 amp electrical systems requires great care and caution. Follow these tips to stay safe:

Rushing the job or taking shortcuts risks electrocution or fires. Following safety protocols is crucial when wiring a 200 amp sub panel in a home.

Wiring a 200 amp sub panel takes careful planning and methodical installation. Understanding sub panel design, grounding techniques, safety protocols, and avoiding common mistakes helps ensure the sub panel meets code and provides safe, reliable expanded electrical capacity in the home.