Siemens SIRIUS 3UG4 - System Overview; Product Description

System overview
3
3.1 Product description
Product description
The tried and tested SIRIUS monitoring relays for electrical and mechanical quantities enable
constant monitoring of all important characteristic quantities that provide information about
the reliability performance of the plant. Sudden disturbances and gradual changes, which may
reveal a maintenance requirement, for example, are both indicated. By means of relay outputs,
the monitoring relays enable direct shutdown of the a󹪜ected sections of the plant as well as
issuing an alarm (e.g. by switching on a warning lamp). To respond 󹪞exibly to short-term
disturbances such as voltage dips or load variation, the monitoring relays have settable delay
times. This avoids unnecessary alarming and shutdowns while enhancing plant availability.
The individual 3UG4 monitoring relays o󹪜er the following functions in various combinations:
• Undershoot and/or overshoot of liquid levels
• Phase sequence
• Phase failure, neutral failure
• Phase asymmetry
• Undershoot and/or overshoot of voltage thresholds
• Undershoot and/or overshoot of current thresholds
• Undershoot and/or overshoot of power factor thresholds
• Monitoring of the active current or apparent current
• Monitoring of the fault current
• Monitoring the insulation resistance
• Undershoot and/or overshoot of speed thresholds
The 3RT2 contactors for mounting on 3RR2 current monitoring relays o󹪜er:
• Phase sequence
• Phase failure
• Undershoot and/or overshoot of current thresholds
• Monitoring of the active current or apparent current
• Monitoring of the fault current
SIRIUS 3UG4 / 3RR2 monitoring relay
Equipment Manual, 07/2021, NEB927043002000/RS-AD/005 21