As part of the building management systems and IT rooms, your Riello UPS will Identify and raise an alarm to notify you, if and when something is wrong.

However identifying whether your UPS requires immediate repairs can be difficult and trying to locate the service records or user manual is not always easy.

Riello units have sophisticated self-diagnostic system, the UPS can check and indicate on the display its status and any errors and/or faults that have occurred during its operation. When a problem arises, the UPS signals the event by showing the code and corresponding type of alarm on the display*.

*Different products may have a different set of alarms, but generally, the below applies to all.

S = Statuses

• These codes indicate the current UPS status
• No user operation is required, this just tells what’s going on
• Example: S04 Load on Bypass (UPS is operating on bypass)

C = Commands

• These codes indicate that a command has been activated
• Shows what commands user has activated
• Example: C08 Bypass Command Active (User has commanded UPS to transfer to bypass via HMI)

W = Warning

• Messages that refer to a specific configuration or operation of the UPS
• These show that there is a condition that may impact the operation of the UPS if not corrected
• Example: W01 Battery Low Warning (UPS is operating from batteries and the autonomy is coming to an end shortly)

A = Anomalies

• Minor problems that do not stop the operation of the UPS, but affect its performance or inhibit the use of some of its functions
• Example: A05 Mains Overvoltage L1 (overvoltage on phase 1 on the input side)

F = Faults

• Faults are problems more critical than “Anomalies” in that, if they persist, they may bring the UPS to a stop
• Example: F23 Output Overload (Loading has exceeded UPS power rating and UPS is on overload)

L = Locks,

• Locks indicate a breakdown of the UPS or one of its parts
• Locks are normally preceded by an alarm signal
• In the event of a fault and resultant breakdown of the inverter, the inverter will be switched off and the load will be powered by the bypass line (this procedure is excluded for breakdowns caused by high and persistent overloads and by short circuits)
• Example: L26 Output Short-circuit L1 (UPS has detected an output low impedance fault in the Phase 1 and has prevented the use of inverter until fault has been cleared)

Below we have provided some of the more common alarm codes for your information:

Constant Power Services are always on hand to discuss any potential problems or queries you may have with both existing installations and new. Below we have described some common or possible faults that may occur and the reason for these.