Specifications

7SR242 Duobias Performance Specification
©2010 Siemens Protection Devices Limited Chapter 3 - Page 8 of 45
1.2.5 Binary (Digital) Inputs
Nominal Operating Range
19 VDC 17 to 290 VDC
V
BI
88 VDC 74 to 290 VDC
1.2.5.1 Performance
At
tribute Value
V
BI
= 19 V 1.5mA
Maximum DC current for
operation
V
BI
= 88 V 1.5mA
Reset/Operate voltage ratio
t 90 %
Response time < 7ms
Response time when programmed to energise
an output relay contact (i.e. includes output
relay operation)
< 20ms
The binary inputs have a low minimum operate current and may be set for high speed operation. Where a binary
input is both used to influence a control function (e.g. provide a tripping function) and
it is considered to be
susceptible to mal-operation due to capacitive currents, the external circuitry can be modified to provide immunity
to such disturbances.
To comply with EATS 48-4, classes ESI 1 and ESI 2, external components / BI pick-up delays are required as
shown in fig. 1-1.
To achieve immunity from AC interference, a BI pick-up delay of typically one-cycle can be applied.