Specifications

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Doc. No
Model
Apparatus
Scale
Page No
1SDH000460R0002
L5439
14.2.2. Electrical characteristics
Rated operating frequency 50/60 Hz ±10%
Pass band 2500 Hz max
Peak factor 2,1 @ 2xIn in conformity to IEC 9472 Annex F.
For greater peak factors,consult ABB
14.2.2.1. Self-powering
Self-powering enables the protection unit to be powered with the busbar current using current transformers.
Using this supply mode, only the unit’s protection functions are assured, however, not the accessory functions regarding the
modules.
The characteristics are given in the table below:
General characteristics Relay Enabling Relay Activation
E1...E3 E4...E6 E1...E3 E4...E6
Minimum three-phase busbar current for enabling relay and switching on
the display
>70 A >140 A >160 A >320 A
14.2.2.2. Auxiliary power supply
The external auxiliary power supply is provided using a galvanically-separated power pack.
WARNING: Since the auxiliary voltage needs to be isolated from the ground, “galvanically separated converters”
in accordance with the IEC standard 60950 (UL 1950) or the equivalent IEC 60364-41 and CEI 64-8 have to be
used to guarantee a current in common mode or leakage current (as defined in IEC 478/1 and CEI 22/3) no
greater than 3.5mA.
The presence of the auxiliary power supply enables the relay unit to be used even with the circuit-breaker open, as well as pow-
ering all the modules, with the exception of the PR120/V - MEASURING module, which is powered by means of a connection to
the busbars.
The characteristics of the power pack are given in the table below.
Characteristics Version PR123/P
Auxiliary voltage (galvanically separated) 24 V DC ±20%
Maximum ripple 5%
Inrush current @ 24 V 10 A for 5ms
Rated power @ 24 V 2W
Current at pickup @ 24 V with connected modules 15 A for 5 ms
Rated power at pickup @ 24 V with connected modules 6W
14.2.2.3. Powered by the PR120/V module
For a full explanation of the features of the PR120/V, see par. 15.1..
14.2.3. Environmental characteristics
Operating temperature -25°C ... +70°C
Storage temperature -40°C ... +70°C
Relative humidity 0% ... 98% with condensation
Degree of protection (with PR122/P installed in the CB). IP 30
14.2.4. Description of inputs/outputs
14.2.4.1. Binary input
– K51/SZin (K51/DFin): Zone selectivity: input for protection S or "direct" input for protection D
(only with Vaux)
– K51/Gzin (K51/DBin): Zone selectivity: input for protection G or "reverse" direction input for protection D
(only with Vaux)
14.2.4.2. Binary outputs
– K51/SZout (K51/DFout): Zone selectivity: output for protection S or "direct" output for protection D (only with Vaux)
– K51/GZout (K51/DBout): Zone selectivity: output for protection G or "reverse" output for protection D (only with Vaux)
14.2.5. Communication bus
Local internal bus on rear connector; RS485 physical interface, Modbus protocol.
External system bus, RS485 physical interface, Modbus RTU protocol, baud rate 9600-19200 bps.
Test bus on front test connector
14.2.6. Protection functions
The PR123/P protection unit carries out 15 independent protection functions. In particular:
1. Protection against overload with inverse time “L”;
2. Protection against short-circuit with adjustable delay “S” and “S2”;
3. Protection against directional short-circuit with adjustable delay “D”;
4. Protection against instantaneous short-circuit “I”;
5. Protection against closing on short-circuit “MCR”
6. Protection against earth fault with adjustable delay “G”;
7. Protection against instantaneous short-circuit at high currents “I inst”;