Product Manual

Table Of Contents
49A045R242 (Issue 7) Copyright © 2016 Cummins Inc.
4 Operation - PowerCommand 1.1
4.1 Sequence of Operation
NOTICE
The following sequences are based on an approximate time duration. Your
generator set may vary slightly from the timing diagrams in this manual. All
referenced times are based on default control settings. The following
sequences are applicable to generator sets connected to a single phase RA
series transfer switch.
Power Outage Sequence
The sequence of operation after a power outage (when the generator set is in Auto
Mode) is as follows:
1. In normal operation, the utility power is running to the transfer switch and then
to the building load, and the generator set is off.
2. The utility power turns off (power outage).
3. One second after the power outage, the transfer switch sends the command to
the generator set to start.
4. The generator set starts and provides voltage to the transfer switch, but the
transfer switch does not switch (allowing the voltage to go to the building) until
after a delay.
FIGURE 17. TIME REMAINING UNTIL TRANSFER SCREEN
5. Five seconds after starting, the generator set provides a signal to the transfer
switch to transfer the building load to the generator set.