Alpha Technologies Cordex 48-1kW 19 6000W Installation - Manual (Page 26)

030-706-B2 Rev B Page 18 of 26
6.10.2 Digital Inputs
The digital input channels are used to monitor various alarm and control signals. All input channels are voltage
activated and accept a bipolar (i.e. negative or positive) DC signal directly.
6.10.2.1 Connection Method
Typical Apha systems use the “reset with Hot and trigger with Ground” connection. The digital
input is wired in such a way that the Hot is wired directly into one of the input terminals; e.g.,
negative input for –48V systems. The other input terminal is wired to the Ground (common) of
the system through a relay (dry contact – usually located on the equipment requiring
monitoring). This method (see Figure 10) allows the digital input to receive (or not receive) a
Ground signal on an alarm.
Figure 10–Showing connection method
6.10.2.2 Programming the Digital Input
The digital input channels can be programmed for “active high” or “active low.” Active high
indicates “alarm on the presence of a ground signal” and active low indicates “alarm on the
removal of a ground signal.” See CXC Software manual for detailed instruction on
programming.
Voltage Range (VDC)
Voltage Level (VDC)
Considered As “0” (Off) Voltage Level (VDC)
Considered As “1” (On)
0—60
(system voltage setting)
0—3 18—60
Table C–Voltage level definitions for digital inputs