3-ZA20B | Edwards EST 20W Zoned Audio Amplifier with 25/70 VRMS Output and NAC Circuit
Edwards EST · Industrial Automation & Electrical
Description The Edwards™ 3-ZA20B is a 20-watt zoned audio amplifier module designed for use in EST3 fire alarm and emergency communication systems. It delivers 25 VRMS or 70 VRMS power-limited audio output and includes a supervised 24 VDC NAC circuit for visual notification appliances. Compact and software-controlled, it provides reliable voice and tone signaling in mass notification and evacuation systems. Technical Specifications Condition New/Never Used Surplus Brand Edwards / EST Category Flame Safety Products Part Number 3-ZA20B Subcategory Flame Safety Amplifier Output Power 20 W at 25 VRMS or 70 VRMS Input 8-channel multiplexed digital audio Input Wiring Class A or Class B Frequency Response 400 Hz to 4 kHz ±3 dB Harmonic Distortion < 7% NAC Circuit 24 VDC, 3.5 A, Class A or Class B EOL Resistor 15 kΩ (internal) Backup Tones 1 kHz evacuation tone, 20 SPM alert tone Wire Size 12 to 18 AWG (4.0 to 1.0 mm²) Space Requirement 1 rail space (LRM) Power Source System power supply via local rail Operating Temp 32 °F to 120 °F (0 °C to 49 °C) Relative Humidity 93% non-condensing Mounting EST3 cabinet, rail-mounted Approvals UL/ULC listed (Indoor dry use) Weight ~1.20 lbs Information About 3-ZA20B The 3-ZA20B is part of the EST3 amplifier series, available in both 20 W and 40 W versions, engineered for fire alarm and mass notification applications. This module supports up to eight multiplexed digital audio channels, with integrated de-multiplexing circuitry allowing selection of live paging or stored messages via system software. Mounted in the EST3 cabinet rail chassis, it requires only one LRM space and uses removable terminal blocks for simplified field wiring. In addition to its audio output, the amplifier includes an independently controlled, supervised, and power-limited 24 VDC NAC rated at 3.5 A for strobes or other visual signaling devices. Its advanced digital processing ensures high intelligibility and compliance with life safety standards. Key Features: 20-Watt Output: Provides 20 W audio at selectable 25 VRMS or 70 VRMS. Integrated NAC Circuit: Built-in 24 VDC power-limited NAC, 3.5 A, Class B or Class A. Multi-Channel Support: Handles up to eight multiplexed digital audio channels. Digital Demultiplexing: Built-in circuitry ensures accurate channel selection via software. Notification Redundancy: Includes 1 kHz evacuation tone and 20 SPM alert tone backup signals. Compact Installation: Occupies one LRM rail space within EST3 cabinets. Software Controlled: Audio channel selection and supervision managed via EST3 system software. Field Wiring Simplicity: Removable terminal blocks for easier installation and service. Fault Supervision: Monitors opens, shorts, and grounds on audio and NAC circuits. UL/ULC Approved: Listed for fire alarm and emergency communication applications. The 3-ZA20B provides dependable, digitally controlled audio distribution for life safety systems.
Brand: Edwards EST · Category: Industrial Automation & Electrical
Key features
- 20-Watt Output: Provides 20 W audio at selectable 25 VRMS or 70 VRMS.
- Integrated NAC Circuit: Built-in 24 VDC power-limited NAC, 3.5 A, Class B or Class A.
- Multi-Channel Support: Handles up to eight multiplexed digital audio channels.
- Digital Demultiplexing: Built-in circuitry ensures accurate channel selection via software.
- Notification Redundancy: Includes 1 kHz evacuation tone and 20 SPM alert tone backup signals.
- Compact Installation: Occupies one LRM rail space within EST3 cabinets.
- Software Controlled: Audio channel selection and supervision managed via EST3 system software.
- Field Wiring Simplicity: Removable terminal blocks for easier installation and service.
- Fault Supervision: Monitors opens, shorts, and grounds on audio and NAC circuits.
- UL/ULC Approved: Listed for fire alarm and emergency communication applications.
Specifications
| Manufacturer part number | 3-ZA20B |
|---|---|
| Condition | New/Never Used Surplus |
| Brand | Edwards / EST |
| Category | Flame Safety Products |
| Part Number | 3-ZA20B |
| Subcategory | Flame Safety Amplifier |
| Output Power | 20 W at 25 VRMS or 70 VRMS |
| Input | 8-channel multiplexed digital audio |
| Input Wiring | Class A or Class B |
| Frequency Response | 400 Hz to 4 kHz ±3 dB |
| Harmonic Distortion | < 7% |
| NAC Circuit | 24 VDC, 3.5 A, Class A or Class B |
| EOL Resistor | 15 kΩ (internal) |
| Backup Tones | 1 kHz evacuation tone, 20 SPM alert tone |
| Wire Size | 12 to 18 AWG (4.0 to 1.0 mm²) |
| Space Requirement | 1 rail space (LRM) |
| Power Source | System power supply via local rail |
| Operating Temp | 32 °F to 120 °F (0 °C to 49 °C) |
| Relative Humidity | 93% non-condensing |
| Mounting | EST3 cabinet, rail-mounted |
| Approvals | UL/ULC listed (Indoor dry use) |
| Weight | ~1.20 lbs |
| Product type | Flame Safety Amplifier |
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