Baomain Universal Rotary Changeover Switch SZW26-40/D303.3D with Master Switch Exterior Box 660V 40A 3 Position 12 Terminals 3 Phase

I purchased this switch to use in my emergency power backup system for our home. I have had a gas powered standby generator for years and wanted to add a solar/battery generator, as well. One generator feeds 240V, 30amp power while the other feeds 120V, 30amp power. I needed a way to connect both generators to an existing transfer switch, but be able to select which power source was feeding the system. This switch was the perfect solution to that need. With three contacts on all sides of the switch, it accommodated the two power legs and neutral from the 240V generator feeding the same on the output side of the switch. The single power leg and neutral from the 120V generator, along with a jumper, provided the other power to the three wire output. Since there were two inputs to the switch going to a single output, three jumpers were also required. Be aware that the knockouts on the switch box are not standard size but are sized for the rubber grommets that come with the box. Consequently, a standard 1/2" or 3/4" cable connector will not work. An optional 2-part cable connector that can be slipped into the knockout holes will be needed. Also, you will have 11 or 12 10ga. solid copper wires coming into this box that will be very hard to compress into the box once your switch is wired. It can be done with special attention to placement of the wires, though, and when place in service, this is a top quality switch.

This switch is surprisingly good for its price. It served us as a temporary selector between an electric dryer and a hybrid water heater. No issues. Installation is simple. It comes with a little schematic, so it's very easy to wire up.

It works. Could cost less.

We try to buy from the Ma and Pa places on here.Being disabled . We need to be price conscious.At "The Mother In Laws Place"It is an off-grid cabin, we run DC on a lot of things .We see no need to use the inverter 24/7.just so you can turn on a light when you come home .We use LED bulbs in ceiling mount fixtures that are marked 12-volt DC only.These are controlled by controller with a FOB remote.The controller is board mounted on our PV control center .We use a few of the controllers for different rooms to control each ceiling light .We also run the kitchen stove exhaust fan with DC .The fresh air intake system for combustion is DC .These are fused in our DC only fuse center .This fuse center is controlled by a service disconnect at the DC master box .We also run two AC fuse boxes on our PV board .One protects various AC 110 volt circuits in the cabin , garage and sauna .We use this as a master switch on part of the systemThe other protects 220 volt circuits from the aux gen set and to the split ac/heat pump and the aux battery charger for when the PV and hopefully soon to be wind generated power are not enough to keep up.We run 8 - 6volt Rolls batteries tied by Buss bars .They are temperature and voltage monitored on the PV board and by the inverter unit.The power is inverted by a Renogy 3000 .It also has a multi stage charger built it with flow through capability .These are almost all protected by Breakers purchased here .We have a remote shallow well system that we use a soft start unit on .It lessens the instant draw on the system .It is all about power management.This is a semi detailed , general description of some of the off grid power systems we use .

Very good transfer switch

Hey everyone, I am an electrician who installed this switch recently in my Garage to use it as a changeover switch for my generator.Review:This product is cheap, but you get what you pay for as an Allen Bradley version would be well over 200$. The cam is simple and comes with four sets of contacts. Do NOT overtighten your screws either as it can cause separation of the individual switches. The casing is thin and cheap, plus it bends too easily if one screw is too tight upon mounting. Maybe buy some reducing washers too to reinforce your knockout holes when you install. Also if you want to use this as a changeover switch you'll have to manually create a set of jumpers for the outgoing feed.LeakageSo after installing this unit in my garage and connecting power I noticed that this unit has a small amount of leakage on the disconnected side. My feed from the house was about 220v @20 Amps. So two legs at 120vac and sharing a neutral. When this unit was switched over to my house feed I found there was about 6 volts AC on the disconnected ( Generator ) side. This isn't much but it could lead to someone getting a shock. I checked my grounding and a few other issues but had determined it must be within the switch itself. The internal contacts separate enough to prevent a big shock but it appears the gap isn't big enough to stop power from jumping across as all three connections have a single-break contact. With voltage leakage this high it could backfeed into your generator to damage it or possibly into the powerlines of your home which could damage small electronics.My personal solution was to create an overly complicated start-stop station using leftover contactors from my job but I wouldn't recommend this to any DIY buyer. Instead I'd recommend using a generator interlock at your breaker panel or generator subpanel with this switch to add more breaks in the line and ensure a full separation of both lines. This is NOT an all in one transfer switch solution so buyer beware, you need to add a little more parts in-line to make this one safe.

This Baomain Universal Rotary Switch is just what I needed to control two circuits independently. The neutral OFF position is perfect too, for when I don't want either of the other two circuits live and functioning. Nice size too! Much easier for wiring. I'm sure that it's a bit of an overkill for my two 115vac circuits, but it's all I needed. And it's a solid switch.