Description
AT&T Avaya Lucent 391A3 Merlin Legend Power Unit 107814848 PBX 700W
The AT&T 391A3 is the dedicated power supply module for the Merlin Legend PBX telephone system, manufactured by AT&T and later sold under the Lucent Technologies and Avaya brand names as the platform changed hands. It provides the regulated multi-voltage DC outputs the Merlin Legend cabinet requires to power its line cards, processor modules, and station ports, along with an optional AC ringing output superimposed on the -48V rail.
Specifications & What's Included
- Model: 391A3 (also referenced as 391A)
- Part Number: 107814848
- Input: 120V AC, 5.4A, 50/60 Hz
- Output 1: +5.1 VDC, 10A
- Output 2: -5.1 VDC, 2.5A
- Output 3: -48 VDC, 3.0A
- Maximum Power: 700 Watts
- Ringing Output (optional): 105V AC, 0.06A, 30 Hz — superimposed on -48V rail
- AC inlet: IEC C14 (standard 3-pin power cord inlet)
- Backplane connection: gold-contact card-edge connector for direct chassis installation
- Test ports: three ports labeled 1, 2, 3 on bottom edge for in-system diagnostics
- Certifications: UL Listed (Telephone Power Supply, file 9784), CSA Listed (Level 3)
- Country of Manufacture: Mexico
- Power unit only — no AC power cord or mounting hardware included
Applications
The Merlin Legend was AT&T's flagship small-to-medium business PBX platform introduced in the early 1990s, offering a modular key/hybrid system that could support analog and digital station cards, voice mail integration, and a range of attendant consoles. The 391A3 Power Unit slots directly into the Merlin Legend cabinet backplane and is the primary power source for the entire system — without it the cabinet will not operate. As the AT&T enterprise communications division was spun off to form Lucent Technologies in 1996 and later became Avaya in 2000, the Merlin Legend platform and its parts continued under those successor brands, which is why this unit appears under all three names. These systems remain in active use in businesses that have not yet migrated to IP-based telephony, and replacement power units are frequently needed when the original fails or a second cabinet is being put back into service.
This AT&T Avaya Lucent 391A3 Merlin Legend Power Unit was pulled from a working phone system but has not been powered up or tested at our facility. The housing is cream-colored with some light yellowing and minor surface scuffs typical of used PBX equipment. The rating label, IEC AC inlet, test ports, and gold-contact backplane edge connector all appear intact and undamaged. Please review our photos and contact us with any questions before purchasing.
Warranty Information
Additional Information
Brand: |
AT&T |
Model: |
391A3 |
Secondary Model: |
391A |
MPN: |
107814848 |
SKU: |
48236 |
Type: |
PBX Telephone System Power Supply |
Compatible With: |
AT&T / Lucent / Avaya Merlin Legend PBX |
Input Voltage: |
120V AC, 5.4A, 50/60 Hz |
Output Voltage 1: |
+5.1 VDC, 10A |
Output Voltage 2: |
-5.1 VDC, 2.5A |
Output Voltage 3: |
-48 VDC, 3.0A |
Max Power: |
700 Watts |
Ringing Output: |
105V AC, 0.06A, 30 Hz (optional), superimposed on -48V |
Form Factor: |
Modular Card/Chassis-Mount Unit |
Power Requirements: |
120V AC, 5.4A, 50/60 Hz |
Country/Region of Manufacture: |
Mexico |
Certifications: |
UL Listed, CSA Listed |
Seller Notes: |
Power unit only — no cables or mounting hardware included. |
Condition Notes: |
This AT&T Avaya Lucent 391A3 Merlin Legend Power Unit was pulled from a working phone system but has not been tested at our facility. Housing shows light yellowing and minor scuffs. All ports and connectors appear intact. Contact us with questions. |
California Prop 65 Warning: |
WARNING: This product can expose you to chemicals including lead and lead compounds, and DEHP (a phthalate), which are known to the State of California to cause cancer and birth defects or other reproductive harm. Go to P65Warnings.ca.gov |
