How to Install a Manual Transfer Switch for a Portable Generator | Ask This Old House

How to Install a Manual Transfer Switch for a Portable Generator | Ask This Old House

Ask This Old House master electrician Scott Caron visits Alaska to install a portable generator with a manual transfer switch to power hardwired appliances like a well pump and heating system using unleaded gasoline.

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Cost: $3,000

Skill Level: Moderate

Tools List for Installing a Manual Transfer Switch for a Portable Generator:
Drill
Lineman’s pliers
Wire strippers

Shopping List:
Portable gas generator
10-circuit manual transfer switch
Power inlet
10-3 non-metallic wiring
Wire nuts

Steps:
1. Mount the manual transfer switch near the main electric panel.
2. Select up to 10 circuits to be powered by the generator (240 volt circuits require two spots on the transfer switch).
3. Turn off power to the house at the main electric shut off.
4. Remove the cover on the main electric panel (work inside the electric panel is only recommended for licensed electricians).
5. Locate an available knockout hole on the electric panel and remove the plug. Attach the armored cable from the transfer switch to the electric panel.
6. Connect the ground and neutral wires from the transfer switch to the appropriate bus bars on the main panel.
7. Locate the first circuit to be powered by the generator and remove the power wire on the existing circuit breaker. Replace that wire with the red wire from the transfer switch marked “A.” Splice the black wire marked “A” from the transfer switch to the removed power wire using a wire nut. Repeat this process for all 10 circuits, ensuring the red and black wires from the transfer switch are a matched pair.
8. Use 10-3 non-metallic wiring to connect the transfer switch to a power inlet outside.
9. Use the provided generator cord to connect the power inlet to the generator (or make your own cable if a longer one is desired using bulk wire and connectors).
10. Ensure the generator has unleaded fuel and oil inside, then start the generator.
11. To test the wiring connections, flip the switches on the transfer switch from “Line” to “Gen.” The generator should power the selected circuits.

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How to Install a Manual Transfer Switch for a Portable Generator | Ask This Old House

Categories: Kitchen Appliance

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Comments

  1. Beto G
    Beto G 17 May, 2022, 11:33

    Can I just turn off main breaker off when outage occurs and then turn on a 30 amp breaker connected to the inlet?

    Reply this comment
  2. ohhhsnap17
    ohhhsnap17 17 May, 2022, 11:33

    It's a Family business 🤣

    Reply this comment
  3. D B
    D B 17 May, 2022, 11:33

    Fake! Generators never start on the first pull.

    Reply this comment
  4. theedrstrangelove
    theedrstrangelove 17 May, 2022, 11:33

    If we buried our power cables like 95% of the planet this would be a non-issue.

    Reply this comment
  5. Mike Yuck-A-Bee
    Mike Yuck-A-Bee 17 May, 2022, 11:33

    Why not solar

    Reply this comment
  6. Real N
    Real N 17 May, 2022, 11:33

    How much does a job like this cost?

    Reply this comment
  7. JEEPARMY USA
    JEEPARMY USA 17 May, 2022, 11:33

    Low key prepper video

    Reply this comment
  8. Anthony Moser
    Anthony Moser 17 May, 2022, 11:33

    go with a propane generator

    Reply this comment
  9. Mitch Herber
    Mitch Herber 17 May, 2022, 11:33

    What brand / model is that transfer switch? I like the layout

    Reply this comment
  10. A J
    A J 17 May, 2022, 11:33

    COME ON, GUYS. PLEASE ANSWER MY QUESTION. ARE YOU GUYS RACISTS? HOW COME YOU HAVE NEVER GONE TO A MINORITY PERSONS HOUSE IN ALL THE YEARS YOU HAVE BEEN DOING THIS SHOW. I HAVE LOOKED AT EVERYTHING I CAN'T FIND AND HAVEN'T SEEN A SINGLE SHOW WITH A BLACK, BROWN OR EVEN BEIGE PERSON. HOW COME?

    Reply this comment
  11. Farmer Brad
    Farmer Brad 17 May, 2022, 11:33

    I was told gas generators can damage well pumps because the variable power generated.

    Reply this comment
  12. Marc Carrier
    Marc Carrier 17 May, 2022, 11:33

    What brand transfer switch box was used in this demonstration?

    Reply this comment
  13. twoweary
    twoweary 17 May, 2022, 11:33

    Like Sean said 4 years ago, and as an electrician, I would agree, these are NOT the way to go today. Hook the generator directly to the panel and install a lockout switch on the panel cover. It allows you to use any circuit in your panel, it’s safe, and doesn’t look like a bunch of spaghetti in the panel. It was fine in its day but not anymore.

    Reply this comment
  14. Rich Thomson
    Rich Thomson 17 May, 2022, 11:33

    Don’t like the plumbing right above the electrical.

    Reply this comment
  15. Odorous Smegma
    Odorous Smegma 17 May, 2022, 11:33

    Bill is short for Billboard FYI.

    Reply this comment
  16. Ed Robens
    Ed Robens 17 May, 2022, 11:33

    How do you deal with the floating neutral issue on portable generators?

    Reply this comment
  17. Robi Bautista
    Robi Bautista 17 May, 2022, 11:33

    Choke close, starts then choke off (open). This electrician isn't very good judging by past episodes and his understanding of how choke works, which is comparable to how an electrical switch works.

    Reply this comment
  18. john doe
    john doe 17 May, 2022, 11:33

    You can't splice wires in a panel

    Reply this comment
  19. Maximus Decimus
    Maximus Decimus 17 May, 2022, 11:33

    I prefer to not have out front where everybody can see it, 4 sec later, proceed to leave it where everybody can see it

    Reply this comment
  20. webadage
    webadage 17 May, 2022, 11:33

    um… he gets high winds year round? Why aren't the leaves on the trees moving? Is this a green screen shot?

    Reply this comment
  21. Will Hansen
    Will Hansen 17 May, 2022, 11:33

    Those transfer switches cannot be mounted flush with that right angle flex connector… common mistake, but will not pass inspection.

    Reply this comment
  22. Philip Breau
    Philip Breau 17 May, 2022, 11:33

    Thank you for posting this video. Very informative.

    Pros and cons I see:

    Pros: 1. It's legal and safe

    Cons:
    1. When running on normal power, there are 2 breakers involved for each circuit with the exception of non essential circuits not on transfer switch. A lot of additional wiring is required. Expensive if you're not a do-it yourselfer and need to hire an LEC.

    2. You can't run a whole house on this setup. I would like to run my whole cottage on a generator. It's 9400W and should be able to power the whole cottage including hot water and stove. Keep in mind I will not have everything in the house running at max draw which may be in excess of the generator output. Question is can I just install a simple transfer switch between the meter base and main breaker?

    Thank you

    Reply this comment

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