Hi I've had as few of the 016B's and hope to have a few more in the future. They are very nice units.
The voltage selector switch chooses which two leads are sent to the panel voltage gage for a reading. The position of the voltage selector switch tells the voltage gage what to read. It is okay to move the switch during operation and nothing is affected operationally.
The 0, 1, 2, 3 on the switch refer to the L0, L1, L2, and L3 on the output block on the back of the contorl box.
For example: you are set in 120 volt single phase mode and have the output hooked up to L1 and L2. Set the switch at V1-2 and it will give you a reading, of the voltage between L1 and L2, hopefully 120 volts.
In 240 volt single phase mode your output is still connected to L1 and L2 but now when the voltage selector switch is moved to V1-2 it will read 240 volts. If you are in the 240 volt single phase mode and move the voltage switch to V1-0, or V2-0 the gage wil read 120 volts which is the voltage between L0 and L1 and also the voltage between L0 and L2.
Same concept in 3 phase mode. Bottom line, by using the voltage selection switch you can see the voltage accross all the combinations of output wirs with only using one gage on the panel. Nice feature on a small gen, really.
When you do a start up and before a load is applied moving the voltage switch to each position will confirm that the selection switch inside the box is set the way you want it for your use.
So to answer your question: For 120 single phase set the voltage switch at V1-2. For 120 three phase the switch can be moved around from V0-1 to check the voltage between L1 and L0 to V0-2 to check the voltage between L2 and L0 and to V0-3 to check the voltage between L3 and L0. All three are active in the three pahse mode and the switch must be moved around to get a separate reading for each pair. Since 3 phase is three separate circuits there may be small differences in the voltage on each line due to load variances if there is different equipment connected to each of the three phase lines. If a three phase device is connected like a 3 phase motor than the voltages would be the same.
Equally useful is the current selector switch that lets one see how much load is on each of the putput lines, L1, L2, L3. when running three phase with 3 separate loads it is useful to balance the loads so I1, I2, and I3 are as equal as possible.
