Contemporary Control Systems AI Active Hubs - Manual (Page 14)

TD675100-0M
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2.4.3 AC Powered
If only AC power is available, the AI can be powered by the
secondary of a low voltage transformer whose primary is
connected to the AC mains. The secondary voltage must be in
the range of 8 to 24 Vac with the capability of delivering up to
4 VA of apparent power. The secondary of the transformer
must not be grounded. When using a grounded secondary
transformer refer to Figure 2-4. For convenience two auxiliary
power supplies are available.
The AI-XFMR is intended for
120 Vac primary power while the AI-XFMR-E is intended for
230 Vac.
Figure 2-3. AC Powered
Figure 2-4. AC Powered with Grounded Secondary
2.4.4 AC Powered with Battery Backup
The AI can also be powered from both an AC and DC power
source. Usually the DC source is from a battery supply which is
connected as the DC powered option. Refer to the diagram for
details. In this application, the AI does not charge the battery so
separate provisions are required for charging.
If the AC source
fails, the AI will operate from the battery source.