MEP-006 Single Phase Conversion
Greetings from the frozen north.
First, I want to thank everyone who posted here, it was very helpful and especially the ease with which the generator leads can be reconnected for single phase.
i realize that this thread is somewhat old... But I thought I would share what I have found in my quest to convert a MEP 006 to single phase. What I found in studying the schematics is that there are some important differences between the 004/005 and the 006. So while the generator lead reconnection is spot on for the 006 I found that there are some differences in the VR and control.
The first thing I discovered is that the regulators in the 004/005 and 006 are quite different.
The 004/005 regulator uses 208/240 volts for the excitation power (although it seems from the earlier posts that it can work with 120 volt) and the 006 regulator uses 120 volts.
The 004/005 also uses an isolation transformer in the input/excitation power circuit and an integrated circuit regulator, whereas the 006 uses a RF filter in the input to clean up the noise and has a discreet regulator circuit.
The good news is that for this to work, all that is needed is to move the two small wires from T-12 to T-11 after cutting the bar and installing the jumper as detailed earlier.
The bad news... If both X12EG16N (control neutral) and X12P16N (regulator lead "M") are not moved from T-12 to T-11 (L-0) and the generator is started it will instantly destroy the RF filter in the regulator and/or the field flash relay.
The reason for this is due to the fact that without an isolation transformer the 006's regulator "M" lead must connect to L-0 or ground. This is T-12 in the original configuration. However, when the conversion is done, T-12 becomes L-2.
So, if X12P16N is not moved, when the field flash relay engages and connects the regulator lead "C" to ground it presents a direct short from L-2 to ground through lead "M", the regulator's RFI, and relay K5.
Also, because of this interaction between the DC and AC sides during the field flash, as well as some controls that reference ground, the neutral and ground must remain connected together in the 006.
Sorry about all the technical stuff, but for those who would be interested...
So, the bottom line is that to do the conversion on a 006 is actually simpler than on the 004/005 in that TB-6 (the reconnection board) is easier to get to.
All that is needed is to cut the strap between T-11 and T-12 and install the jumper as detailed in the earlier posts and videos and move the two small wires X12EG16N and X12P16N from T-12 to T-11 (or T-10).
Another thing that that can be done is to install a double-pole switch to switch the big jumper from T-12 to either T-8 or T-11 for single or three phase operation without changing any wiring back over.
Hope this helps...