ABB AC 800M

Section 2 Installation Power Supply Supervision
3BSE 027 941 R301 83
+ 24 V on the SA/SB indicates working power supplies. 0 V on SA/SB indicates an
error in the corresponding power supply and lack of redundancy. SA/SB signal
connection is shown in Figure 19 on page 81, Figure 20 on page 82, Figure 21 on
page 83 and Figure 22 on page 84.
Figure 19 on page 81 and Figure 20 on page 82 show redundant power supplies
powering AC 800M units. Here the SA/SB signals also indicate physical power
supplies.
Figure 22 on page 84 shows one redundant power supply powering the AC 800M
units and one for powering field equipment. An SA/SB error indication can not
indicate which physical power supply that has failed, only that there is a failure.
To avoid error indications from SA/SB when single power supply is used, it is
recommended to connect the input terminals SA/SB on the CPU to +24 V,
see Figure 21 on page 83.
Figure 21. Connection of SA/SB using Single Power Supply
PM861
L+
L–
SA
SB
+24
V
0V