Siemens PAD-4-MB NAC Expander Replacement Board

The Siemens PAD-4-MB is the factory replacement control board used in all PAD-4 distributed power supplies and NAC expander kits. Swapping in this board restores the PAD-4’s four supervised output circuits, two trigger inputs, on-board battery charger, strobe-sync generator, ANSI Temporal coding, status LEDs, and dual trouble relays without replacing the entire cabinet or power supply. Key Specifications: Application: Replacement main board for PAD-4-6A, PAD-4-6A-CLSA, PAD-4-9A, and PAD-4-9A-CLSA units Output Circuits: Four 24 V DC power-limited NAC/aux outputs (Class B) – convertible to two Class A when a PAD-4-CLSA adapter card is installed Total Load: Supports up to 6 A (with 170 W supply) or 9 A (with 300 W supply) depending on host kit Trigger Inputs: Two supervised inputs, 16–33 V DC (reverse polarity) or dry contact Sync & Coding: Built-in System Sensor, Wheelock, Gentex, AMSECO sync; ANSI Temporal 3 and Temporal 4 patterns Battery Charger: Charges two 7 Ah or 18 Ah batteries in the cabinet; up to 18 Ah remotely Trouble Relays: Form C general-trouble and Form A AC-fail contacts Indicators & Controls: Power, fault, and output status LEDs; DIP-switch programming – no software required Compatibility: Drops onto the existing PAD-4 backplate and mates with either the 170 W (6 A) or 300 W (9 A) Siemens power-supply modules Related Parts & Accessories: PAD-4-CLSA – Class A output adapter card PAD-4-ENCL – Replacement enclosure FP2011-U1 – 170 W power-supply module (6 A) FP2012-U1 – 300 W power-supply module (9 A)