AB Allen-Bradley 1756-PB50 Slim ControlLogix DC Power Supply Module

Product Summary

The Allen-Bradley 1756-PB50 is a Slim ControlLogix DC Power Supply by Rockwell Automation. It provides 24V DC input power conversion for ControlLogix chassis, delivering up to 8 A at 5.1V DC to the backplane. Its slim form factor reduces cabinet space requirements while maintaining full compatibility with all standard ControlLogix I/O modules and controllers.

Core Specifications

• Model Number: 1756-PB50
• Type: ControlLogix Slim DC Power Supply
• Input Voltage: 18–32V DC (nominal 24V DC)
• Maximum Input Power: 50W at 50°C; 60W at 0–50°C
• Output Current @ 5.1V DC: 8A (0–50°C); 6A (0–60°C)
• Output Current @ 1.2V DC: 1.5A
• Output Current @ 3.3V DC: 2A
• Output Current @ 24V DC: 2.0A (60°C)
• Maximum Surge Current: 30A
• Isolation Voltage: 250V continuous
• Weight: 1.7 lbs (0.77 kg)
• Dimensions: 5.51 × 3.07 × 5.71 inches
• Manufacturer: Allen-Bradley by Rockwell Automation

Electrical & Functional Characteristics

• Power Conversion: Converts 24V DC input to multiple backplane voltages (1.2V, 3.3V, 5.1V, 24V)
• Slim Design: Reduced width compared to standard 1756-PB72/PB75 power supplies for space-constrained cabinets
• Installation: Mounts in left slot of 1756 ControlLogix chassis
• Enclosure: Open-style (none)
• Wiring: 2.5 mm² (14 AWG) solid or stranded copper wire rated at 90°C minimum; max insulation 1.2 mm

System Integration & Compatibility

• Compatible Chassis: 1756-A4, 1756-A7, 1756-A10, 1756-A13, 1756-A17 (Series A, B, C)
• Compatible Controllers: All 1756-L6x, 1756-L7x, 1756-L8x ControlLogix and GuardLogix controllers
• Compatible I/O: All 1756-series I/O modules within power budget
• Related Power Supplies:
  • 1756-PA50 — Slim AC power supply (85–265V AC)
  • 1756-PB72 — Standard DC power supply (18–32V DC, 10A @ 5V)
  • 1756-PB75 — High-capacity DC power supply (18–32V DC, 13A @ 5V)
  • 1756-PC75 — 24V DC direct backplane power supply
  • 1756-PH75 — 120/240V AC high-capacity power supply

Environmental & Operational Limits

• Operating Temperature: 0°C to 60°C (32°F to 140°F)
• Storage Temperature: -40°C to +85°C (-40°F to 185°F)
• Humidity: 5% to 95% RH, non-condensing
• Vibration: 2G, 10 to 500 Hz
• Shock: 30G operating; 50G non-operating
• Approvals: CE, UL, CUL

Industrial Applications

Widely deployed in manufacturing, material handling, packaging, process skids, and OEM machines where 24V DC input power is preferred and cabinet space is limited.

Frequently Asked Questions

What is the difference between 1756-PB50 and 1756-PB72?

The 1756-PB50 is a slim DC power supply delivering 8A @ 5.1V. The 1756-PB72 is a standard-width DC power supply delivering 10A @ 5.1V. The PB50 saves cabinet space but provides less current capacity.

Can I use the 1756-PB50 with any ControlLogix chassis?

Yes — it is compatible with 1756-A4, -A7, -A10, -A13, -A17 chassis (Series A, B, C). Verify total backplane current draw does not exceed the PB50's 8A @ 5.1V rating.

What wire size do I need?

Use 2.5 mm² (14 AWG) solid or stranded copper wire rated at 90°C (194°F) or higher, with maximum insulation diameter of 1.2 mm.

What are the related part numbers?

• 1756-PA50 — Slim AC power supply (85–265V AC)
• 1756-PB50 — Slim DC power supply, 24V DC input (this part)
• 1756-PB72 — Standard DC power supply, 10A @ 5V
• 1756-PB75 — High-capacity DC power supply, 13A @ 5V
• 1756-PC75 — 24V DC direct backplane power supply
• 1756-PH75 — 120/240V AC high-capacity power supply