WE BUY & SELL INDUSTRIAL GENERATORS
Established 1981

Generator Voltage Changes

Many of our generator sets have the capability to have the output voltage changed. The generator identification tag will identify the voltages. We have the technical expertise and capability on-site to change both single and 3-phase generators. The most common wiring configurations for voltage change are:
 
  • 120/240 VAC Single Phase
  • 120/208 VAC 3-Phase
  • 277/480 VAC 3-Phase

120/240 VAC Single Phase

Generator armature rotates through the two windings. Each winding produces electrical current. Each winding produces 120 VAC. Combining windings to one another or to neutral connection controls generator output at the supply side output terminals (Figure 1).

Generator windings are illustrated in a different color to illustrate voltages produced. Voltage changes can be easily translated into:
 
  • Voltage between any two winding will be 240 VAC
  • Voltage between any single phase and neutral will be 120 VAC

Changing Voltage
Some generators feature an external plug socket that allows for either 120 or 240 VAC connections via extension cord. This allows for easy access of either voltage for temporary connections. Generators that do not have this feature rely on hardwire connections at the generator (Figure 1). Our experienced staff can change generator output voltage (generator must be equipped for change). 

The technician connects the appropriate generator output wires to obtain the desired voltage. Start up and load tests are performed on generators that have voltage configuration changes.

Figure1a.JPG
Figure 1, 120/240 VAC Single Phase Connections

120/208 VAC 3-Phase

Generator armature rotates three windings. Each winding produces electrical current. Current from each winding is considered to be one phase. Combining the phases to one another or to neutral connection controls generator output at the supply side output terminals (Figure 2).

Generator windings are illustrated in a different color to illustrate different phases. Voltage changes can be easily translated into:
 
  • Voltage between any two phases will be 208 VAC
  • Voltage between any single phase and neutral will be 120 VAC

Changing Voltage
Some generators feature a voltage select switch. This allows for voltage selection without changing hardwire configurations. Generators that do not have this feature rely on hardwire connections (Figure 2). Our experienced staff can change generator output voltage (generator must be equipped for change). 

The technician connects the appropriate generator output wires to obtain the desired voltage. Start up and load tests are performed on generators that have voltage configuration changes.

Figure2a.JPG
Figure 2, 120/208 3-Phase VAC Connections

277/480 VAC 3-Phase

Generator produces current with the same winding configuration. The generator prime mover (engine) is larger to support a more robust generator winding setup. Combining windings to one another or to neutral connection controls generator output at the supply side output terminals (Figure 3).

Generator windings are illustrated in a different color to illustrate different phases. Voltage changes can be easily translated into:
 
  • Voltage between any two phases will be 480 VAC
  • Voltage between any single phase and neutral will be 277 VAC
Changing Voltage
If the generator features a voltage select switch, do not need a hardwire configuration performed. Our experienced staff can change generator output voltage (generator must be equipped for change). 

The technician connects the appropriate generator output wires to obtain the desired voltage. Start up and load tests are performed on generators that have voltage configuration changes.

Figure3a.JPG
Figure 3, 277/480 VAC Connections