Alpha Technologies CXPS-HD 48-1.2-225 - Manual (Page 28)

0530082-J0 Rev B Page 20 of 31
5.10 Signal wiring connections for controller
Reference is made to drawings located at the rear of this manual. Custom configurations may be detailed within
the Alpha power system documentation package.
For terminal block connections, the recommended wire sizes are #16 - #26 AWG (1.5 - 0.129 mm 2 ) for the
temperature range of 0 - 50°C (as per UL/CSA).
CAUTION: To reduce risk of fire, use only #26 AWG (0.129 mm 2 ) or larger wire.
Bundle the signal cables together and route them through the entry holes of the shelf.
5.10.1 Alarm (relay) outputs
Terminals provide contacts for extending various alarm or control signals. Each relay output can be wired for NO
or NC operation during an alarm or control condition. See Figure 6.
Figure 6–Showing relay connections
Relays can be programmed to energize or de-energize during an alarm condition. See the controller software
manual. All relays will de-energize when the controller reset button is pressed or when the power is lost.
5.10.2 Digital inputs for controller
The factory-installed digital input channels are used to monitor various alarm and control signals. All input
channels are voltage activated and directly accept a bipolar (negative or positive) DC signal.
D1 and D2 are available for customer connections.
5.10.2.1 Connection method
Typical Alpha systems use a “reset with Hot and trigger with Ground” connection. The digital input is wired so that
Hot is wired directly into one of the input terminals; e.g., negative input for -48 V systems. The other input terminal
is wired to the common ground of the system through a relay, which is a dry contact usually located on the
equipment that requires monitoring. This method allows the digital input to receive or not receive a Ground signal
during an alarm. See Figure 7.
Figure 7–Showing digital input connection method