Product Description:

The C9900-U120 uninterruptible power supply is produced by Beckhoff within the C9 PC Accessories series. In a control cabinet, it bridges brief mains losses so that industrial PCs, fieldbus gateways, and motion controllers can close files, park axes, or log faults before power disappears. Its tower form factor minimizes floor space, and the unit is explicitly a UPS for Beckhoff automation computers that do not include internal batteries.

An audible alarm is deferred by 5 s, giving a short window to acknowledge a power anomaly before the buzzer sounds. Every 14 days, the unit performs an automatic self-test that briefly discharges the battery pack to verify capacity. Batteries leave the factory disconnected to prevent parasitic drain, yet they can be replaced while the UPS remains in service because they are hot-swappable. After connection, an initial charge of 4 h is required to reach rated runtime. A low-battery warning is issued two minutes before shutdown, flagged both acoustically and through the serial data port, and the interval is set to 2 min. The UPS also supports cold start, so it can power attached loads from battery even if utility power is absent. A configurable shutdown timer works with the host PC to finish tasks before power is cut. Return capacity is reported as 0% until the first full charge calibration is completed.

For networked controls, the unit includes surge suppression on the Ethernet pass-through and protects links at 10/100BASE-TX speeds. If a mains failure persists, it waits 60 s before sending the final stop command over the serial interface and opening the relay contacts. Telephone or DSL lines share the same surge module and are presented on an isolated RJ-45/RJ-11 port. When acceptable input voltage returns, the UPS starts delivering power immediately, and the specified turn-on delay is 0 s, preventing unnecessary downtime for PLCs or HMI panels.