Hello To All!
I hope you all don't mind that this isn't an electronics question, but more of an electrical engineering question.
I have a portable, single phase generator. The control panel has two output choices: 120 Volts Only or 120/240 volts.
In the owner's manual it states that in 120 volt only mode all of the 120 volt devices (NEMA 5-20R & NEMA L5-30) are using the "full output power of the alternator". It further states that in 120/240 volt mode, only half of the alternator's output power is available at the 120 volt devices, with the other half at the 120/240 volt device (NEMA L14-30R).
Testing with a volt meter shows that in both 120 Only and 120/240 Modes, the 120 volt devices are indeed on the same phase. Also on that phase is half of the 120/240 device. The other half of the device is not powered in this mode (as expected).
In 120/240 volt mode, the 120 volt devices are still on the same phase, along with half of the 120/240 volt device. The other half of the 120/240 volt device is, as expected, on the other phase.
To me, this means that in 120/240 Volt Mode, one stator winding supplies "phase a" and one supplies "phase b". But how does the alternator supply all of the alternator's output to the 120 volt devices in 120 Volt Only mode? Surely the windings, which are 180-degrees apart, can't suddenly be in phase by the flip of a switch.
When I tested in 120 Only mode I expected that some of the 120 volt devices would be moved to "phase b", but the meter shows that this is not the case. I studied the wiring diagram for hours, left and came back. Still, I can't figure out the magic. (To be honest, I'm old enough that my brain isn't as logical as it once was, so there's an "old guy" factor involved.)
Attached is the wiring diagram. Can any of you help me understand how the second half of the alternator's output is made available to the 120 devices in 120 Volt Only mode?
I very much appreciate the help and education.
Thanks Again & Please Enjoy This Day!
Paul
I hope you all don't mind that this isn't an electronics question, but more of an electrical engineering question.
I have a portable, single phase generator. The control panel has two output choices: 120 Volts Only or 120/240 volts.
In the owner's manual it states that in 120 volt only mode all of the 120 volt devices (NEMA 5-20R & NEMA L5-30) are using the "full output power of the alternator". It further states that in 120/240 volt mode, only half of the alternator's output power is available at the 120 volt devices, with the other half at the 120/240 volt device (NEMA L14-30R).
Testing with a volt meter shows that in both 120 Only and 120/240 Modes, the 120 volt devices are indeed on the same phase. Also on that phase is half of the 120/240 device. The other half of the device is not powered in this mode (as expected).
In 120/240 volt mode, the 120 volt devices are still on the same phase, along with half of the 120/240 volt device. The other half of the 120/240 volt device is, as expected, on the other phase.
To me, this means that in 120/240 Volt Mode, one stator winding supplies "phase a" and one supplies "phase b". But how does the alternator supply all of the alternator's output to the 120 volt devices in 120 Volt Only mode? Surely the windings, which are 180-degrees apart, can't suddenly be in phase by the flip of a switch.
When I tested in 120 Only mode I expected that some of the 120 volt devices would be moved to "phase b", but the meter shows that this is not the case. I studied the wiring diagram for hours, left and came back. Still, I can't figure out the magic. (To be honest, I'm old enough that my brain isn't as logical as it once was, so there's an "old guy" factor involved.)
Attached is the wiring diagram. Can any of you help me understand how the second half of the alternator's output is made available to the 120 devices in 120 Volt Only mode?
I very much appreciate the help and education.
Thanks Again & Please Enjoy This Day!
Paul
Attachments
-
100.2 KB Views: 18