Description
The Siemens PAD-4-9A is a distributed power supply and NAC (Notification Appliance Circuit) expander designed to enhance Siemens fire alarm control panels by providing additional 24 V DC power for signaling devices. This model delivers up to 9 amps of total output power, supporting both audible and visual notification appliances compliant with ADA standards. Its fault-tolerant circuitry ensures consistent operation, making it ideal for large commercial, industrial, and institutional fire alarm installations.
Technical Specifications
| Condition |
New/Never Used Surplus |
| Brand |
Siemens |
| Category |
Fire Safety |
| Part Number |
PAD-4-9A |
| Subcategory |
NAC Power Expander |
| Output Voltage |
24 V DC regulated |
| Total Output Power |
9 A maximum |
| Auxiliary Output |
3 A @ 24 V DC |
| NAC Circuits |
4 × Class B (Expandable to Class A with PAD-4-CLSA) |
| Inputs |
2 × optically isolated NAC inputs |
| Supervisory Relays |
Form C (General Trouble and AC Fail) |
| Battery Capacity |
Up to 7 Ah internal; larger capacities supported with optional kits |
| Operating Voltage |
120 VAC, 50/60 Hz |
| Output Regulation |
Independent of primary power fluctuation |
| Certifications |
UL 864 10th Edition, ULC-S527, ADA Compliant |
| Enclosure Material |
Red powder-coated steel |
| Mounting |
Wall-mounted enclosure |
| Production Status |
Active |
| Weight |
5 lbs |
Information About
PAD-4-9A
The PAD-4-9A is part of Siemens’ advanced Distributed Power Supply (PAD) Series, built to expand the power and signaling capacity of Siemens FireFinder and other compatible FACPs. It provides four Class B NAC outputs (expandable to Class A with the PAD-4-CLSA module) and a 3 A auxiliary output for auxiliary equipment such as door holders and relays. The unit features integrated supervision for AC loss, ground faults, and battery conditions, ensuring reliable fault reporting through Form C relays. Engineered for long-term performance, the PAD-4-9A maintains a regulated 24 V DC output independent of power source fluctuations, ensuring stable device operation across extended wiring runs.
Key Features:
- High NAC Power Output: Provides up to 9 A of 24 V DC power for notification appliances.
- Multiple Circuit Configurations: Supports four Class B circuits, expandable to Class A using the PAD-4-CLSA option.
- Auxiliary Power Supply: Delivers 3 A of 24 V DC power for auxiliary devices such as relays and door holders.
- Supervised Inputs and Outputs: Monitors AC power, batteries, ground faults, and output integrity through Form C relays.
- Optically Isolated NAC Inputs: Ensures reliable signal separation and prevents cross-interference with the main panel.
- Integrated Strobe Synchronization: Supports synchronization modules for consistent strobe operation across zones.
- Durable Enclosure Design: Housed in a red, metal enclosure with space for power boards and batteries up to 7 Ah or larger.
- Seismic and Safety Certifications: Complies with UL 864 10th Edition, ADA, and IBC/OSHPD seismic standards.
The PAD-4-9A delivers the reliability and precision required for critical fire alarm power distribution and signaling system expansion.
