ABB SPA-ZC Bus Connection Modules
Features • Electrical-to-optical converter for the SPA
bus
• Connects the substation secondary
devices to the fibre-optic SPA bus
• High immunity to electrical and electromag netic interference
• Easy mounting and installation
• Complete range of bus connection mod ules for different applications
• Products of the SPACOM product family
and ABB’s Substation Automation system
Application The SPA bus interconnects the substation
protection relays, annunciator systems and
other devices by means of a fibre-optic loop
based on a glass or plastic fibre cable. The
devices are connected to the bus over bus
connection modules type SPA-ZC_ which
convert the electrical signals of the devices to
optical signals for the bus and, vice versa, the
optical signals of the bus to electrical signals
of the devices. All the standard secondary
devices of a substation are equipped with a
serial interface for receiving and transmitting
information.
The serial ports of the devices are TTL,
RS 485 or RS 232 C signal level interfaces.
Bus connection modules are available for
these interface types.
Design The SPA bus connection modules are used in
both ends of the SPA bus, i.e. on the substa tion level for connection of the bus to the
communication units and on the feeder level
for connection of the bus to the substation
secondary devices.
Bus connection module
SPA-ZC 17
The bus connection module SPA-ZC 17 is
used for connecting substation secondary
devices to the SPA bus. It converts the TTL or
RS 485 level signals of the host device to
fibre optic signals for the bus and vice versa.
The unit comprises one 9-pin D type connec tor for the host device and one pair of optical
transceivers for the SPA bus. The module can
be powered from the host device or from a
separate power source. In the latter case the
bus connection module and the fibre-optic
bus remain operative, should the power sup ply from the host device be interrupted.
The bus connection module SPA-ZC 17 can
be used in both master and slave mode.

Bus connection module
SPA-ZC 20
The bus connection module SPA-ZC 20 is
used for multiplying the number of available
fibre-optic loops in a substation. The module
is provided with 15 transceiver pairs, that is it
can form 15 fibre-optic loops. All of the loops
formed by the module carry the same information. In certain applications, where operational reliability is of primary concern it can
be recommended to limit the number of substation secondary devices connected to one
single loop. In these applications the bus connection module SPA-ZC 20 is applied.
The SPA-ZC 20 is only used in master mode
and it is powered from the device to which it
is connected. The input interface of the
device is of the RS 485 type.
Bus connection module
SPA-ZC 21
The bus connection module SPA-ZC 21 is
used for connecting substation secondary
devices to the SPA bus. It converts the TTL or
RS 485 level signals of the host device to
fibre optic signals for the bus and vice versa.
The unit comprises one 9-pin D type connector for the host device and one pair of optical
transceivers for the SPA bus. The module is
powered from the host device.
The bus connection module SPA-ZC 21 can
be used in both master and slave mode.
Bus connection module
SPA-ZC 22
The bus connection module SPA-ZC 22 is
used for dividing the system into several
fibre-optic loops. The SPA-ZC 22 module is
available in two versions, one with five fibreoptic transceiver pairs and one with two pairs.
The SPA-ZC 22 module is connected to the
communicator units of the SPA loop. The bus
connection module features a built in
RS 232 C interface for direct connection to a
PC, a modem, etc. and one RS 485 interface
for connection to e.g. a SRIO unit. The bus
connection module can also be used in slave
mode if a double connection to one substation
secondary device is needed. The third mode
of operation for the SPA-ZC 22 module is the
optical repeater mode. In the optical repeater
mode a fibre pair from the communicator
unit's optical module is connected to the first
transceiver pair of the SPA-ZC 22 module.
The data is then retransmitted over the other
transceiver pair(s) in the module.
The bus connection module SPA-ZC 22 is
powered form the device to which it is connected or from an external power source.
Technical data
Ordering
Table 1: Power supply
From host device SPA-ZC 20
SPA-ZC 21
From host device and external supply SPA-ZC 17
SPA-ZC 22
Supply voltage when supplied from external source 80…265 V ac or dc
18…80 V dc
When ordering, please specify:
Ordering information Ordering example
1. Type designation and quantity SPA-ZC 17BB2A, 5 pieces
2. Order number RS 951 014-AA
3. Auxiliary voltage Uaux, if applicable 110 V dc
Order numbers of bus connection module SPA-ZC 17
Type designation Auxiliary supply Transmitter Receiver Order No.
SPA-ZC 17BB2A 80…265 V ac, dc Plastic Plastic RS 951 014-AA
SPA-ZC 17BB2C 18…80 V dc Plastic Plastic RS 951 014-BA
SPA-ZC 17BM2A 80…265 V ac, dc Plastic Glass RS 951 014-CA
SPA-ZC 17BM2C 18…80 V dc Plastic Glass RS 951 014-DA
SPA-ZC 17MB2A 80…265 V ac, dc Glass Plastic RS 951 014-EA
SPA-ZC 17MB2C 18…80 V dc Glass Plastic RS 951 014-FA
SPA-ZC 17MM2A 80…265 V ac, dc Glass Glass RS 951 014-GA
SPA-ZC 17MM2C 18…80 V dc Glass Glass RS 951 014-HA
Order numbers of bus connection module SPA-ZC 17 for SACO units
Type designation Auxiliary supply Transmitter Receiver Order No.
SPA-ZC 17BB2A/S 80…265 V ac, dc Plastic Plastic RS 951 014-AB
SPA-ZC 17BB2C/S 18…80 V dc Plastic Plastic RS 951 014-BB
SPA-ZC 17BM2A/S 80…265 V ac, dc Plastic Glass RS 951 014-CB
SPA-ZC 17BM2C/S 18…80 V dc Plastic Glass RS 951 014-DB
SPA-ZC 17MB2A/S 80…265 V ac, dc Glass Plastic RS 951 014-EB
SPA-ZC 17MB2C/S 18…80 V dc Glass Plastic RS 951 014-FB
SPA-ZC 17MM2A/S 80…265 V ac, dc Glass Glass RS 951 014-GB
SPA-ZC 17MM2C/S 18…80 V dc Glass Glass RS 951 014-HB
Order numbers of bus connection module SPA-ZC 20
Type designation Transmitter Receiver Order No.
Plastic Glass Plastic Glass
SPA-ZC 20 15B0M 15 0 15 0 RS 951 020-AA
SPA-ZC 20 10B5M 15 0 15 1 RS 951 020-BB
SPA-ZC 20 5B10M 15 0 15 2 RS 951 020-CB
SPA-ZC 20 0B15M 15 0 15 3 RS 951 020-DB