Rosslare AC-225? AC-225IP? AC-225U - Inputs Description

Input and Output Requirements
Normally Closed Supervised Single Resistor Input Connection
Connect a 2.2K resistor 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 12: Normally Closed Supervised Input (Single Resistor)
Normally Closed Supervised Double Resistor Input Connection
Connect a 2.2K resistor in series to the input switch contacts.
Connect an 8.2K resistor 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.
AC-225 Hardware Installation and User Guide Page 21