Siemens 3UG4 - Configuration of Load Feeders

3RR2 current monitoring relays
4.3 Performance features of current monitoring relays
3UG4 / 3RR2 monitoring relays
Manual, 05/2016, NEB927043002000/RS-AC/004
51
4.3.3
Configuration of load feeders
Table 4- 6 Load feeders with 3RR2 current monitoring relays
Feature
Benefit
3RR21 Basic,
analog setting
3RR22 Standard,
digital setting
Short-circuit-proof up to 100 kA at
690 V
(in conjunction with the appropriate
fuses or the appropriate motor starter
protector)
•
Provides optimum protection of the loads
and operating personnel in the event of
short circuits due to insulation faults or
faulty switching operations
✓ ✓
Electrical and mechanical matching to
3RT2 contactors
• Simplifies configuration
• Reduces connection outlay and costs
• Enables stand-alone assembly as well
as space-saving direct mounting
✓ ✓
Spring-loaded connection system for
main circuit (option) and auxiliary
circuit (option)
• Enables fast connections
• Ensures that connections are vibration-
resistant
• Enables maintenance-free connections
✓ ✓