





3-ZA20A | Edwards 20W Zoned Amplifier, 25/70 VRMS, Class A/B Audio & 24VDC NAC
- Regular price
- $334.00
- Sale price
- $334.00
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Product Description P/N: 3-ZA20A
Description
The Edwards 3-ZA20A is a 20-watt zoned amplifier module designed for EST3 fire alarm and emergency communication systems. It delivers supervised Class A or Class B audio output at 25 VRMS or 70 VRMS for distributed speaker circuits. The 3-ZA20A also includes an integrated 24 VDC, 3.5 A Notification Appliance Circuit (NAC) for visual signaling devices.
Technical Specifications
Condition | New/Never Used Surplus |
Brand | Edwards |
Category | Flame Safety Products |
Part Number | 3-ZA20A |
Subcategory | Flame Safety Amplifier |
Output Power | 20 W |
Audio Output Voltage | Selectable 25 VRMS or 70 VRMS |
Audio Circuit Wiring | Class A or Class B |
NAC Circuit Voltage | 24 VDC nominal |
NAC Current | 3.5 A maximum |
Digital Audio Input | 8-channel multiplexed, demultiplexed on board |
Frequency Response | 400 Hz to 4 kHz at ±3 dB |
Harmonic Distortion | < 7% |
EOL Resistor | 15 kΩ (internal) |
Current (Standby) | 62 mA |
Current (Alarm) | 1.12 A |
Wire Size | 12 to 18 AWG (4.0 to 1.0 mm²) |
Module Size | 1 LRM space |
Operating Temperature | 32°F to 120°F (0°C to 49°C) |
Humidity | Up to 93% RH, non-condensing |
Agency Listings | UL/ULC approved |
Weight | 3.00 lbs |
Information About 3-ZA20A
The 3-ZA20A is part of the EST3 family of audio amplifiers, engineered to support mass notification and evacuation applications. The unit integrates demultiplexing circuitry, allowing it to select and output one of eight multiplexed digital audio channels distributed across the system. Designed for flexibility, the 3-ZA20A supports Class A (Style 7) and Class B (Style 4) wiring configurations for both speaker circuits and the NAC. Mounted in one LRM space, the amplifier operates directly from system power supplies via the local rail and connects through removable terminal blocks for simplified installation.
Key Features:
- 20-Watt Audio Output: Provides reliable power for small to medium speaker circuits.
- Selectable 25/70 VRMS: Compatible with both standard speaker voltages in fire alarm and MNEC systems.
- Class A/B Audio Circuits: Supports either Class A or Class B wiring for flexibility in system design.
- Integrated NAC: Built-in 24 VDC NAC rated at 3.5 A for visual notification devices.
- Digital Audio Integration: Demultiplexing circuitry allows channel selection from up to eight digital audio inputs.
- Software Controlled: Network-based configuration enables easy channel assignment and monitoring.
- Removable Terminals: Simplifies field wiring and troubleshooting.
- Compact Design: Requires only one rail space for efficient use of enclosure space.
- Low Distortion: Frequency response of 400 Hz to 4 kHz with <7% harmonic distortion ensures intelligible voice audio.
- UL/ULC Listed: Certified for use in fire alarm and emergency communication systems.
The 3-ZA20A delivers the reliability and performance needed for high-quality voice and signal amplification in Edwards EST3 life safety systems.
Description
The Edwards 3-ZA20A is a 20-watt zoned amplifier module designed for EST3 fire alarm and emergency communication systems. It delivers supervised Class A or Class B audio output at 25 VRMS or 70 VRMS for distributed speaker circuits. The 3-ZA20A also includes an integrated 24 VDC, 3.5 A Notification Appliance Circuit (NAC) for visual signaling devices.
Technical Specifications
Condition | New/Never Used Surplus |
Brand | Edwards |
Category | Flame Safety Products |
Part Number | 3-ZA20A |
Subcategory | Flame Safety Amplifier |
Output Power | 20 W |
Audio Output Voltage | Selectable 25 VRMS or 70 VRMS |
Audio Circuit Wiring | Class A or Class B |
NAC Circuit Voltage | 24 VDC nominal |
NAC Current | 3.5 A maximum |
Digital Audio Input | 8-channel multiplexed, demultiplexed on board |
Frequency Response | 400 Hz to 4 kHz at ±3 dB |
Harmonic Distortion | < 7% |
EOL Resistor | 15 kΩ (internal) |
Current (Standby) | 62 mA |
Current (Alarm) | 1.12 A |
Wire Size | 12 to 18 AWG (4.0 to 1.0 mm²) |
Module Size | 1 LRM space |
Operating Temperature | 32°F to 120°F (0°C to 49°C) |
Humidity | Up to 93% RH, non-condensing |
Agency Listings | UL/ULC approved |
Weight | 3.00 lbs |
Information About 3-ZA20A
The 3-ZA20A is part of the EST3 family of audio amplifiers, engineered to support mass notification and evacuation applications. The unit integrates demultiplexing circuitry, allowing it to select and output one of eight multiplexed digital audio channels distributed across the system. Designed for flexibility, the 3-ZA20A supports Class A (Style 7) and Class B (Style 4) wiring configurations for both speaker circuits and the NAC. Mounted in one LRM space, the amplifier operates directly from system power supplies via the local rail and connects through removable terminal blocks for simplified installation.
Key Features:
- 20-Watt Audio Output: Provides reliable power for small to medium speaker circuits.
- Selectable 25/70 VRMS: Compatible with both standard speaker voltages in fire alarm and MNEC systems.
- Class A/B Audio Circuits: Supports either Class A or Class B wiring for flexibility in system design.
- Integrated NAC: Built-in 24 VDC NAC rated at 3.5 A for visual notification devices.
- Digital Audio Integration: Demultiplexing circuitry allows channel selection from up to eight digital audio inputs.
- Software Controlled: Network-based configuration enables easy channel assignment and monitoring.
- Removable Terminals: Simplifies field wiring and troubleshooting.
- Compact Design: Requires only one rail space for efficient use of enclosure space.
- Low Distortion: Frequency response of 400 Hz to 4 kHz with <7% harmonic distortion ensures intelligible voice audio.
- UL/ULC Listed: Certified for use in fire alarm and emergency communication systems.
The 3-ZA20A delivers the reliability and performance needed for high-quality voice and signal amplification in Edwards EST3 life safety systems.


