Unit installation

Input and Output Connections
AC-215IP Hardware Installation Manual 23
4.1.5 Normally Closed Supervised Single Resistor Input Connection
Connect a resistor of 2.2 K in series to the input switch contacts.
Normally Closed Supervised Input has 3 states:
 Switch Closed – Normal State:
Loop resistance = 2.2 K
 Switch Open – Abnormal State:
Loop resistance = Infinite (open circuit)
 Short circuit across input terminals – Trouble State:
Loop resistance = 0 (short circuit)
Figure 13: Normally Closed Supervised Input (Single Resistor)
4.1.6 Normally Closed Supervised Double Resistor Input Connection
Connect a resistor of 2.2 K in series to the input switch contacts.
Connect a resistor of 8.2 K parallel to the input switch contacts.
Normally Closed Supervised Input has 3 states:
 Switch Closed – Normal State:
Loop resistance = 2.2 K
 Switch Open – Abnormal State:
Loop resistance = 10.4 K
 Open circuit (Infinite loop resistance) or short circuit (0 resistance) across
input terminals – Trouble State