Where can I buy the wiring needed for a home standby generator installation?

This article explains where to buy the wiring needed for a Generac home standby generator installation, including control wiring and generator installation cable. It clarifies that Generac does not provide all installation wiring, and what you receive can vary by what you purchased and where you bought it. It also covers what to do if your cable includes extra conductors, like unused purple wires, and why you should follow the installation manual and local codes. This helps ensure a safe, correct installation and reliable operation.

  • May 7, 2026
  • Knowledge

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Where can I buy the wiring needed for a home standby generator installation?
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Where-can-I-buy-the-wiring-needed-for-a-home-standby-generator-installation

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Read the manual thoroughly and understand all of the instructions, cautions, and warnings before using this equipment. If any section of the manual is not understood, contact your nearest authorized dealer, or contact Generac Customer Service at 1-888-436-3722 (1-888-GENERAC), or www.generac.com with any questions or concerns. 

Where can I buy control wiring for my standby generator?

Some home standby generator (HSB) installations require additional materials such as power wiring, control wiring, conduit, and fittings that may not be included with the generator or automatic transfer switch (ATS). In many cases, installers or dealers supply the materials needed as part of the installation. If you are purchasing materials yourself, this article explains where to buy them and what to do before connecting anything, including when a pre-made generator cable includes extra conductors.

Environment

  • Generac residential standby generators
  • Generac automatic transfer switches (ATS)

Issue or Question

Customers may purchase a generator and/or transfer switch and then realize the installation needs additional wiring that is not included in the box. Others may purchase a multi-conductor generator cable and notice extra wires, such as purple wires, and be unsure whether those conductors are needed.

Answer

Generac does not provide all wiring required for every home standby generator installation. What wiring you receive, if any, can vary based on what you purchased and where you bought it. Your generator and ATS installation manuals, along with local electrical codes, determine what materials are required.

Before you buy wiring

1. Use your generator and transfer switch installation manuals to confirm recommended conductor sizes, insulation type, and any control wiring requirements.
2. Follow national and local electrical codes and consult a licensed electrician or qualified service personnel to confirm the correct materials for your site and installation requirements.
3. If you need product manuals, use the product lookup page to find documentation for your model.
 
Important: Generac Customer Support cannot provide wire sizing recommendations beyond what is listed in the installation manual. For more information, see What Size Wiring Do I Need for My Automatic Home Standby Installation?

Where to buy wiring for an HSB installation

  • Generac dealers and installers: Many home standby installations are sold as turnkey projects where the dealer or installer supplies the required wiring, conduit, fittings, and other installation materials. You can find a local installer using the dealer locator.
  • Local electrical supply houses or home improvement retailers: These are common sources for electrical wire, conduit, fittings, and other installation materials required by code.
  • Online wiring suppliers: Some customers purchase multi-conductor generator installation cable online. One example is Ziller Electric’s generator wire collection.
Note: Third-party product offerings can change. Always confirm the cable or wiring material meets your generator and ATS requirements and local code before purchasing or installing.

What if my generator cable includes extra wires (example: purple wires)?

Some generator cables include extra conductors that may not be used in every installation or may be intended for optional accessories or alternate configurations. Wire colors and conductor counts vary by cable manufacturer. When purchasing a cable, select one with the appropriate number of conductors for your generator and ATS model based on the wiring documentation.

 1. Do not connect unknown wires “just to try it.” Incorrect connections can cause improper operation, damage, and injury.
2. Match each conductor to the wiring diagram in your generator and ATS documentation and the cable documentation from the seller or manufacturer.
3. If a conductor is not required by the wiring diagram, leave it unused and safely secure it per code by capping or insulating it as required and keeping it protected in the wiring compartment.
4. If you are unsure, contact a licensed electrician or a Generac IASD for assistance.
 

For general information about control wire purpose and common control wire designations used in home standby installations, see What is the layout of the control wires and what do they do?.

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