ABB CI570 3BSE001440R1 MasterFieldbus module
Resetting the trip commands/-signals
The following resetting modes can be selected for each binary output (tripping or signal
outputs):
• Latches until manually reset
• Resets automatically after a delay
Inspection/maintenance
A binary input is provided that excludes a bay
unit from evaluation by the protection system.
It is used while performing maintenance
respectively inspection activities on the primary equipment.
Redundant power supplies (Option)
Two power supply modules can be fitted in a
redundant arrangement, e.g. to facilitate
maintenance of station batteries. This is an
option for the central unit as well as for the
bay unit.
Time synchronization
The absolute time accuracy with respect to an
external time reference depends on the
method of synchronization used:
• no external time synchronization:
accuracy approx. 1 min. per month
• periodic time telegram with minute pulse
(radio or satellite clock or station control
system): accuracy typically ±10 ms
• periodic time telegram as above with second pulse: accuracy typically ±1 ms
• a direct connection of a GPS or DCF77 to
the central unit is possible: accuracy typically ±1 ms
• Furthermore, the time synchronization can
be done, if available, via the interbay bus
IEC103, LON or SNTP (in case IEC61850-
8-1 is used)
The system time may also be synchronized by
a minute pulse applied to a binary input on the
central unit.

Optical fiber cables
A distributed busbar protection layout requires optical fiber cables and connectors with
the following characteristics:
• 2 optical fiber cores per bay unit
• glass fibers with gradient index
• diameter of core and sheath 62.5,
respectively 125 m
• maximum permissible attenuation 5 dB
• FST connector (for 62.5 m optical fibers)
• rodent protected and longitudinally waterproof if in cable ducts
Please observe the permissible bending
radius when laying the cables.
The following attenuation figures are typical
values which may be used to determine an
approximate attenuation balance for each
bay:
Fig. 9 Attenuation
Isolator auxiliary contact
Auxiliary contacts on the isolators are connected to binary inputs on the bay units and
control the status of the busbar replica in the
numerical busbar protection.
One potentially-free N/O and N/C contact are
required on each isolator. The N/O contact
signals that the isolator is “CLOSED” and the
N/C contact that the isolator is “OPEN”. During the closing movement, the N/O contact
must close before the isolator main contact
gap reaches its flashover point.
Conversely, during the opening movement,
the N/O contact must not open before the isolator main contact gap exceeds its flashover
point.
If this is not the case, i.e. the contact signals
‘no longer closed’ beforehand, then the N/C
contact may not signal “OPEN” before the
flashover point has been exceeded.