Rosslare AC-215IP, Installation Manual, Page: 23 / 37

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