Main features:

Zero impact source

Multi Sentry solves installation problems in systems where the power supply has limited power available, where the UPS is supported by a generator or where there are compatibility problems with loads that generate harmonic currents; Multi Sentry has a zero impact on its power source, whether this is the mains power supply or a generator:

• input current distortion < 3%
• input power factor 0,99
• power walk-in function that ensures progressive rectifier start up
• start-up delay function, to restart the rectifiers when mains power is restored if there are several UPS in the system.

In addition, Multi Sentry plays a filtering and power factor correction role in the power network upstream of the UPS, as it eliminates harmonic components and reactive power generated by the power utilities.

Battery care system

Proper battery care is critical to ensuring correct UPS operation in emergency conditions. The Riello UPS battery care system consists of a series of features and capabilities to optimise battery management and obtain the best performance and operating life possible. Battery recharging: Multi Sentry is suitable for use with hermetically sealed lead-acid (VRLA), AGM and GEL batteries and Open Vent and Nickel Cadmium batteries. Depending on the battery type, different charging methods are available:

• One-level voltage recharge, typically used for widely available VRLA AGM batteries
• Two-level voltage recharge according to IU specification
• Charge blocking system to reduce electrolyte consumption and lengthen the life of VRLA batteries.

Recharge voltage compensation based on temperature in order to prevent excessive battery charges or overheating.

Battery tests to diagnose in advance any reduction in performance or problems with the batteries. Deep discharge protection: during extended low-load discharges, the end-of-discharge voltage is increased – as recommended by battery manufacturers – to prevent damage or reduced battery performance. Ripple current: recharge ripple current (residual AC component) is one of the main causes of reduced reliability and battery life. Using a high frequency battery charger, Multi Sentry reduces this value to negligible levels, prolonging battery life and maintaining high performance over a long period of time. Wide voltage range: the rectifier is designed to operate within a wide input voltage range (up to – 40% at half load), reducing the need for battery discharge and thus helping to extend battery life.

Maximum reliability and availability

Distributed parallel configuration of up to 8 units per redundant (N + 1) or power parallel system. The UPS continue to operate in parallel even if the connection cable is interrupted (Closed Loop).

Advanced communications

Multi Sentry is equipped with a back-lit graphic display (240×128 pixels) providing UPS information, measurements, operating states and alarms in different languages. It can also display wave forms and voltage/ current forms. A wide range of comunications options are available to ensure global and comprehensive UPS monitoring.