Product Review: Generator Interlock for Standby Power

If you are like me, you want to have a backup plan. I do this in my professional role for data protection, why not do the same at home! Note: Consult a qualified electrician for your panel modifications.

When I lived in West Michigan, we had many occurrences of multi-day power outages and we installed an interlock kit for a safe feed for generator power. Since we’ve moved to this new house, I decided to go ahead and get a kit installed here. Here is the generator we bought in 2005 or so:


On the right side, the 4-pole interface is a 240-volt, 20-amp interface (L14-20P). Now this generator is nice, but it doesn’t have the legs to run everything in the house. Namely, I have to turn off the Rickatron lab datacenter and avoid running the air conditioner and electric dryer. Heat (natural gas), kitchen, garages and lighting however can run on this generator. I’d like to have had a 30-amp / 9000 Watts or so unit; but this is what I have.

While I don’t live in such a rural area now, there is always the risk of a power outage. And the way I see it, the problem is solved either way:

Power goes out: I’m good.

Power stays on: I’m good.

My natural choice in this situation is a manual kit, I call it a “double-throw bypass switch” but basically it’s an interlock kit. I have a Siemens electrical panel at home and bought the right kit for my house and feed from

Here is how these systems work:

  • The panel has two breakers added to bring in power in my case 2×20 AMP feeds from my generator.
  • The Interlock switch keeps these two breakers off until there is a power incident.
  • When you have a power incident, you connect your generator feed and start the generator.
  • Then throw the two switches to provide a feed that is a closed system from the generator that is safe and to code.

Let’s walk through the steps. The picture below is my panel after the Interlock kit has been installed and is the normal running configuration when I have municipal power:


The top 2 right breakers are the input from the generator, and the interlock kit keeps them off during normal situations (when municipal power is on).

It’s a good idea to test the system, for the following reasons:

  • You are familiar with the process works
  • You know the pieces and parts work
  • You will extend the life of the generator by keeping it running occasionally

To hook up the generator a proper installation has a weatherproof box installed on the exterior of the house (with an adequate gauge going to the panel, again leverage the qualified electrician).  Part of the solution is to have a long cable going from the weatherproof box to the generator. This is shown below (and the other end of this cable goes to the generator):


Once the wiring is in place, I can switch the panel to use the generator feed. Note the two steps below:

  • Stop the municipal feed
  • Switch the interlock
  • Activate the feed from the generator



While the generator (5500 running/7000 max Watts | 20 Amp) doesn’t have the full power for this house, it does keep the heat on, the kitchen going and all lights as well as TV and cable. This solves my concern on what to do if/when the power goes out. Further, this is the “Few-Hundred-Dollar Solution” compared to autoswitch standby systems:

Generator:  $400-600

Interlock Kit: up to $150

Electrician: up to $300

If you get a full house, auto-switch generator, it can easily get to a $10,000 solution. Further, those generators run on natural gas – which you can’t assume will be in place at all times. I keep enough fuel for 2 days of generator runtime, which is nice to ensure that I’m managing that process.

Final verdict: Interlock Kit A+ | Highly Recommend.

3 responses to this post.

  1. This is really a very good information about interlock kit for a safe feed for generator power i always needed.


  2. Standby generators like 9000 watt power are usually better useful for big industrial use. This review really informative and helpful for choose a better standby generator. However thanks for sharing such a post.


  3. Great information! The Generator Interlock for Standby Power is a standard quality product for standby generator. It’s really helpful.


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