ABB 5SHX2645L0002 3HB012961R0001 SCR control unit module
Bus connection moduleSPA-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 connec tor 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 fibre optic 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 con nected 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