Application; Hardware Versions - ABB REX 521 Technical Reference Manual, General

1MRS 751108-MUM
2.2.
2.3.
Protection Relay
Technical Reference Manual, General

Application

The REX 521 is designed for protection of incoming and outgoing feeders in
medium voltage distribution substations. Further, the relay can, e.g., be applied to
back-up protection of power transformers and back-up for high voltage line
protection relays.
Several standard configurations are available for the protection relay. Please, refer to
REX 521 Technical Reference Manual, Standard Configurations
(1MRS 751802-MUM).

Hardware versions

Table 2.3.-1 Hardware versions of the REX 521
Relay type
Version name
Transformer modules (MIM)
Transformers
• Current transformers 1/5 A
• Current transformers 0.2/1 A
• Voltage transformers 100 V
Sensor channels
• Current sensor inputs
• Voltage sensor inputs
Main CPU modules
CPU_SP (SPA/ IEC plastic)
CPU_SG (SPA/ IEC glass)
CPU_LP (SPA/ IEC/ LON plastic)
CPU_LG (SPA/ IEC/ LON glass)
Power supply modules
PS_87H (DItresh.=80 Vdc)
PS_87L (DItresh.=18 Vdc)
Display module
2 x 16 character display
Digital inputs
High-speed power outputs
Power outputs (PO)
Signalling outputs (SO)
IRF outputs
Trip-circuit supervision (TCS)
REX 521
Basic Medium High
1 1 1
4 4 4
1 1
1 4
1 1 1
1 1 1
1 1 1
9
1
3
2
1
1
REX 521
Sensor
1
1
1
1
3
3
1
1
1
7