Milbank MMTS501SYSL2C - 50-Amp (6-Circuit) Power Transfer Switch System w/ 25' Cord

The Obvious reason to purchase this transfer switch system is to accommodate a back-up generator. I'm using a 8000/10000w in this application.

The GOOD: Well made, well thought out design. You're basically going to create a sub-panel for circuits that will be powered by your generator when 'the lights go out'. The box itself is completely pre-wired, and has wire labels to correspond with each circuit breaker installed, so there's really no guess work. This does not require the whole house to be disconnected from your power service when using your generator. No worry about back-feeding to the power lines.
The switch itself will not allow a dangerous condition when the main switch on the transfer panel is operated. Both main breakers on the transfer panel can be turned off, but only one can be "ON" at a time, so you can't run the generator AND service power at the same time. Good safety feature seeing you're not working this in ideal conditions... (the lights are out!) Instructions are also clearly marked in the panel for operating the transfer switch safely.
This box is an indoor or outdoor location box. The panel door is typical outdoor design, with a top hinge, so the door swings up and out and locks open fairly easily. There is also loops to lock the door closed if your install is outside.
The LED meters supplied work well, and give a good baseline with power consumption on either leg of the 240v input. This metering system will help you determine which breakers to use for each leg of power, to even out the service load on the generator.

You will need a 100A/240V Main breaker that fits your existing electrical panel to feed this subpanel. I also needed to buy two additional breakers for the transfer panel, as all my breakers were 20A, making the (2) supplied 15A breakers 'extras'. Also make sure you'll have room in your panel for the 100A breaker, keeping in mind you can remove breakers that will be 'transferred' into the transfer box.

The BAD: Well, there's nothing really 'bad', but there are some issues that arise with a pre-wired set up. Here's what I found. If you decide to install a remote plug as I decided, the twistlock outlet in the transfer switch box.is better off removed, and there's no plate supplied to cover that hole, so I had to fabricate one especially if this is installed outside. The pre-wiring is a curse IF you wanted the wiring to go out of the box from a different place. It would require pretty much taking the whole thing apart to re-wire it. Not my case, but notice where the wiring comes out of the box before you buy to save some angst. If you wanted to use a larger diameter conduit, you're taking the thing apart, because there's no larger knockout where the wiring exits. You're making a bigger hole yourself.

OPERATION: Once installed, and tested on service power, following the directions on the panel makes switching over to the generator safe and easy, as is switching back. The meters set-up in seconds, and allow you keep a manageable load on your generator.

This is NOT a weekend warrior project... you NEED to know what you're doing. Once installed, "Easy to Use" is a pro, installation is not easy for someone not familiar with electrical work.