ABB REG670 - Shunt Resistor Unit REX062

22.4 Shunt resistor unit REX062
22.4.1 Introduction
REX062 is typically used when injection is done via a grounding transformer.
22.4.2 Design
REX062 for stator protection is used when either injection via a grounding
transformer (i.e. not via a VT) is used or when maximum voltage posed on injection
equipment by the generator is bigger than 120V.
REX062
Shunt Resistor unit
Injection A
Injection B
External A
External B
I sense B
I sense A
Fuse
PE
IEC11000041-2-en.vsd
IEC11000041 V1 EN
Figure 571: REX062 Principal design
REX062 input protection
REX062 limits overvoltage by a varistor at the injection output to stator. Normally ,
REX060 will interrupt the injection circuit in case of excessive over-current in the
injection chain. Fuse within REX062 is an additional protection in case of failure
within REX062 during over-voltage condition.
A blown REX062 fuse requires a module disassembling to replace the fuse (F 6.3 A
250 V). However, if this occurs it is recommended to identify the reason for the over-
current and do needed actions to reduce the current.
1MRK502052-UEN B Section 22
Injection equipment hardware
1231
Technical manual