Appendix B: Paralleling UPS Devices
Linear Plus Series User Instruction Manual
37
Step C
1. Remove cover of the parallel port of all parallel devices for linking between UPSs.
2. Use the 25-pin standard control cable to connect to one of the parallel ports (the cable is supplied with
the UPS). Parallel UPS are connected in-line, not in a circle, i.e., 2 cables connect 3 UPSs, 1 cable
connects 2 UPSs.
Step D
1. Close the UPS input breakers (main1/bypass) of UPS 1, then UPS 2, and UPS3.
2. Close the mains supply distribution circuit breaker. All bypass indicators should illuminate
simultaneously.
3. Switch the bypass switch (located under orange cover) on the rear of UPS 1 from “OFF” to “UPS”.
4. On UPS 2 repeat step 3.
5. On UPS 3 repeat step 3.
6. Close all UPS downstream circuit breakers/fuses to the load distribution.
NOTE:
At this point all UPSs will be in parallel “BYPASS” mode. This mode will allow for full rated
output of the parallel system. UPS will have the “BYPASS” LED illuminated.
7. Press the “MENU” button on UPS 1.
8. Select submenu “CONTROL.”
9. Press “OK”, the LCD displays ‘TURN UPS TO ONLINE.”
10. Press “OK”, the UPS system will stay waiting in “BYPASS” mode.
11. Repeat step 7-10 on UPS 2 and UPS 3.
NOTE:
After a few seconds, the “BYPASS” LEDs on UPSs will extinguish and all “ON” LED’s will
illuminate simultaneously, indicating that all parallel UPS inverters are running. The total load is spread
evenly across all UPSs.
