I think I found my answer in the User manuals for the EU series and some digging on the RV.net forums.
Manuals for all 3 EU models are available at Hondas website. Each one has a circuit diagram.
http://www.hondapowerequipment.com/Gen_ ... /g_own.htm
On the EU2000 circuit diagram they show the two NEMA plugs protected by a fuse.
On the EU1000 and 3000 they do not show the fuse.
The Parallel Ports are NOT protected by the fuse on any of the models.
Now, here is the really important stuff:
The Inverter output on the EU1000 and the EU3000 are not polarized and each line delivers 62V. They are marked as Red and Red on the schematic.
Since the EU2000 is the only model with a circuit breaker, it makes good sense to speculate that it is polarized and marked as such with Red and White wire in the schematic.
So, I would venture an educated guess that it is probably a good idea to stick with connecting like units in parallel. I can understand how the inverters will sync the clocks of the 60Hz signal, but running 120V & Neutral in parallel with 62V & 62V(out of phase) … Makes me wish those brain cells with the trigonometry classes I smoked and drank away were with me again. For all I know it might work fine but it just doesn’t seem right.
A fellow in the rv.net forums also posted a bunch of pictures on some of his solutions to connecting like units. Of interest is the confirmation of the lack of fuse on the EU2000 parallel port and polarity. Also he dissected the $250 Honda module. What a rip-off.
http://www.picturetrail.com/gallery/view?p=6&uid=558963&
Bottom line is:
To get parallel operation you pull cables in parallel from either the NEMA or Parallel Port from each unit.
If you use the Parallel Port, you bypass the built in circuit breaker on the EU2000 but should pay attention to polarity.
If I had to build a cable, I would get Honda OEM cables for the EU1000 then modify them. The EU1000 cables are the cheapest, ~ $35. Cut them in half, run the cut end into a box, install circuit breakers on both lines for EU1000/3000 units or on phase line (red) for EU2000, add appropriate NEMA plug for the resultant Amperes.
Cap’n, I do not like the method you are mentioning since the NEMA plugs have exposed live rails if one pulls the cord out while a genny is running. Considering that most folks have the idea that a standard plug dangling in the air is safe, easy for someone to fry their nuts off. I would use the shielded Honda cables and the Parallel Ports unless you have a clever way of locking the NEMA plugs.
Standard Disclaimer: The post above contains information about modifying electric circuits that carry lethal voltage and currents. You could die if you attempt any of the items listed above.
