75
Connector Meaning
X72 Mainmodule RS232 service or debug interface
X73 HMI connection
X74 Time synch input
X75 HSTS Input
X76 HSTS Input
X77 HSTS Output
X80 Analog inputs
X81 Sensor 1
X82 Sensor 2
X83 Sensor 3
X84 Sensor 4
X85 Sensor 5
X86 Sensor 6
X87 Sensor 7
X88 Sensor 8
19.1. Analog Inputs
REF 542plus can have a maximum of 8 analog input channels. These inputs are
divided into three measurement groups:
*
Measurement Group 1: channel 1, channel 2, channel 3
*
Measurement Group 2: channel 4, channel 5, channel 6
*
Measurement Group 3: channel 7, channel 8
Group 1 and group 2 have to be homogeneous, which means they can measure 3
currents or 3 voltages. For example, measurements of 1 current and 2 voltages are
not allowed.
Group 3 can get any type of signals: 2 currents, 2 voltages, 1 current and 1 voltage
and so on. Group 1 and group 2 can be used for homogeneous current or voltage
measurements both from instrument transformers and non-conventional sensors.
Group 3 can be used in a heterogeneous way.
Channel 7 and 8 in group 3 can be used for earth-fault current with CT type input;
residual voltage, or for the synchrocheck function with VT or sensor type input.
The input CT 0.2A is commonly used with a toroidal transformer for sensitive earth-
fault current measurement.
Instrument current transformers can have secondary windings ratio /1 A or /5 A. The
primary nominal current (for example 400 A) is selected with the Operating Tool.
The secondary current (for example /5 A) is automatically selected connecting the
right wire to the analog input module.
Multifunction Protection and Switchgear Control Unit
Operator's manual
REF 542plusREF 542plus
1MRS755869