SIRIUS 3RU2/3RB3 overload relays   
5.10 Technical data 
  SIRIUS Innovations 
544  System Manual, 01/2011, A8E56203870002-03 
Type  3RU21 16  3RU21 26 
Size  S00  S0 
Width  45 mm  45 mm 
Short-circuit protection 
  With fuse 
- Operating class gL/gG  A  6  
- Quick-response  A  10 
  With miniature circuit breaker  
(C characteristic) 
A  6
2)
 
Protective separation between auxiliary 
current paths 
acc. to IEC/EN 60947-1 
V  440 
CSA, UL, and UR rated data 
Auxiliary circuit – Switching capacity  B600, R300 
1)
  On request  
2)
  Up to 
I
k
≤ 0.5 kA; ≤ 260 V 
5.10.2.5  Conductor cross sections, auxiliary circuit 
Table 5- 42  Technical data for the auxiliary circuit connection, 3RU21 overload relays 
Type  3RU21 16  3RU21 26 
Size  S00  S0 
Width  45 mm  45 mm 
Connection type  Screw connection 
  Connection screw 
M3, Pozidriv size 2 
  Operating tool 
mm  ∅ 5 to 6 
  Tightening torque 
Nm  0.8 to 1.2 
  Conductor cross-sections (min./max.), 1-wire or 2-wire 
- Solid  mm
2
  2 x (0.5 to 1.5)
1)
; 2 x (0.75 to 2.5)
1)
 
- Finely stranded with end sleeve 
(DIN 46228 Part 1) 
mm
2
  2 x (0.5 to 1.5)
1)
; 2 x (0.75 to 2.5)
1)
 
 
- AWG cables, solid or stranded  AWG  2 x (20 to 16)
1)
, 2 x (18 to 14)
1)
 
Connection type  Spring-loaded connection 
  Operating tool 
mm  ∅ 3.0 x 0.5. ∅ 3.5 x 0.5 
  Conductor cross-sections (min./max.) 
- Solid  mm
2
  2 x (0.5 to 2.5) 
- Finely stranded without end 
sleeve 
mm
2
  2 x (0.5 to 1.5) 
- Finely stranded with end sleeve 
(DIN 46228 Part 1) 
mm
2
  2 x (0.5 to 1.5) 
 
- AWG cables, solid or stranded  AWG  2 x (20 to 14)