SIRIUS 3RV2 motor starter protectors   
4.9 Accessories 
  SIRIUS Innovations 
422  System Manual, 01/2011, A8E56203870002-03 
4.9.7  Phase barriers/UL 508 "type E" terminals 
4.9.7.1  Description 
"Self-protected combination motor controller (type E)" according to UL 508 
3RV20 motor starter protectors are approved as "Self-Protected Combination Motor 
Controller" (Type E) according to UL508.  
The increased clearances and creepage distances required for this application on the input 
side of the device (1 inch and 2 inches respectively) are achieved by adding terminal blocks.  
1.  The 3RV29 28-1H terminal block is screwed to the basic device. 
2.  The 3RV2928-1K phase barriers are connected to the device. 
The terminal block is recommended for the connection of larger conductor cross-sections. 
 
 
Note 
CSA 
CSA approval does not require extended clearances and creepage distances. 
 
Function 
To ensure optimum protection against flashover between the connected conductors in the 
event of a short circuit, phase barriers/terminals can be used. The phase barriers/terminals 
are required to increase the clearances and creepage distances in conjunction with 
prevailing switching overvoltages during motor starter protector switching. The phase 
barriers/terminals increase the insulation strength between the motor starter protector's 
connection contacts.  
Restriction 
The terminal block and the phase barriers cannot be used simultaneously with 3RV19.5 3-
phase busbars. If phase barriers are being used, the motor starter protectors can only be 
mounted on DIN rails.  
Versions 
The terminal block and the phase barriers are only available in screw designs. They can only 
be mounted on the motor starter protector using screw-type connection systems.