Here is how I made a parallel kit for my Honda Inverter EU1000 and EU2000 generators. This should make a safe (no hot unshielded "suicide" plugs), cheaper ($55 vs $100+), easy to use kit to parallel your generator and combine your output.
1. I am a handyman, not an electrician or electrical engineer. So be careful and use this for your own knowledge, be careful, and don't blame me.
2. I Believe this only works on inverter generators, but is not specific to just Honda (should work with Honda, Ryobi, Generac, etc.)
3. Honda claims you can only parallel 2 identical models, I.e 1000 to 1000, 2000 to 2000 etc. But I believe it works fine with a 1000 paralled to a 2000
4. When I decided to make this Instructable, I had already completed the project without any pictures, so I did the best I could as a after thought.
Step 1: Supplies Needed
Pliers - Common Needle nose should be fine (or electrical pliers) to cut, crimp, and strip wires
Phillip head screw driver
1. Extension Cord 10-25 ft...14 or 16 gauge
2. 1 Gang Weatherproof Electrical Outlet Box with Three 1/2 in. Holes
3. Plug to match your need/wants...I used a 30 AMP L14-30 plug..another common is L5-30, various RV, etc
4. 2xScrew Cable Clamps (used to clamp wires coming into outlet box)
5. 4xBanaana Plug Connectors-4mm Fully Insulated
6. 2xInsulated Fork Spade Wire Connector (walmart, Auto Zone, Amazon...usually come in a pack)
7. ~4in of scrap wire (14 or 16 gauge)
Step 2: Assemble - Wire Cut/strip
1. Cut both male and female ends off extension cord (I left a few inches with the plug so they may be useful for something in the future)
2. Cut total length in half
2. On both lengths and both ends, strip back outer sheathing about 6 inches (be careful not to knick inner wire insulation)
3.On both lengths and both ends, strip each wire's insulation back a few millimeters (about the length of your finger nail)
Step 3: Assemble Plug/Box
1. Screw cable clamps to two opposite box holes (tighten inner lock ring and leave outer lock down screws loose)
2. Feed wire end through hole and clamp, leave loose and feed enough to work with
3. Repeat with second length and second hole.
**depending on the receptacle you want, next steps may change...follow plug instructions**
4. Attach wires to receptacle. Follow directions, black to hot, white to neutral, green to ground
NOTE: The plug I used is a 220v L15-30 plug. My
house is already wired for input with this plug for my large generator that puts out 220v. This parallel conversion allows ease of use to plug one or two small generators into my house with this same plug/cable etc, ##BUT## Most 1000-3000 watt inverter generators do not put out 220v (only 110v), and there is no reasonable way to make a small generator put out 220v. You simply need a bigger generator.
**If you want to use a 220v outlet like me, attach both black wires to "hot" attachment screws (sometimes simply brass), both white to neutral spot (silver screw), both green to ground (green screw), then use a 4" "jumper wire" (scrap wire is fine) to connect each brass/"hot" screw to each other (so both wires have an equal feed/load). **BUT you will still only have 110v available, so if you use any 220v appliances (i.e. most A/C's, electric hot water tank, Electric dryer/stove etc) you will severely damage them or cause injury.**
5. Push attached outlet into box (pulling on outer wires will help). Screw outlet and sometime the cover at the same time into box. Pull outer wires until somewhat snug, if you pull too hard you will rip wires out of outlet.
6. Tighten cable clamps until snug.
Step 4: Final Step: Assemble Generator Ends
1. Wires should already but stripped and ready to go. If not, do so.
2. Attach banana clips as shown. I am terrible at soldering, so I simplely made sure the wires were snug and secure.
3. Ensure black clips attach to black wires on both sides, and red to white wires. Note: Honda claims it doesn't matter, but better safe then sorry
4. Attach fork to green wire and crimp with a crimping tool or strong pliers (ensure wire is snug in place)
That's it, you are good to go!