2025-05-01

Allen-Bradley’s ControlLogix power supplies, identified under the 1756 series, serve as the power foundation for ControlLogix systems using 1756 chassis. These robust industrial supplies power backplanes with 1.2V, 3.3V, 5V, and 24V DC outputs and are essential in mission-critical automation applications. This guide details the technical specifications of each variant to assist in proper selection and implementation.

1. Standard AC Power Supplies

Models: 1756-PA50, PA50K, PA72/C, PA72K/C, PA75/B, PA75K/B
Input Voltage: 85–265V AC (Nominal: 120/240V AC)
Frequency: 47–63 Hz

Key Specs:

• Input Power: PA50 models: 81W @ 50°C, 68W @ 60°C; PA72/PA75: 100W

• Output Power: PA50: 50–60W; PA72/PA75: 75W

• Inrush Current: 20A

• Hold Up Time: 5–20 cycles depending on model and voltage

Current Output (DC):

• 1.2V: 1.5A

• 3.3V: 2A (PA50); 4A (PA72/PA75)

• 5.1V: 8A (PA50); 10A (PA72); 13A (PA75)

• 24V: 2.5A (PA50); 2.8A (PA72/PA75)

Compatibility: Chassis A, B, C; Models: A4, A7, A10, A13, A17
Mounting: Left side of chassis
Wire Size: 2.5mm² copper (solid/stranded)
Weight: 0.77kg (PA50); 0.95kg (PA72/75)
Dimensions: 14 x 7.8 x 14.5 cm (PA50); 14 x 11.2 x 14.5 cm (PA72/75)

2. Standard DC Power Supplies

Models: PB50, PB50K, PB72/C, PB72K/C, PB75/B, PB75K/B, PC75/B, PH75/B

Input Voltage:

• PB models: 18–32V DC (Nominal: 24V)

• PC75/B: 30–60V DC (Nominal: 48V)

• PH75/B: 90–143V DC (Nominal: 125V)

Input Power: 70–95W depending on model and temp Output Power: 50–75W depending on model and temp Inrush Current: 30A Hold Up Time: 40–50ms

Current Output (DC):

• 1.2V: 1.5A

• 3.3V: 2A (PB50); 4A (others)

• 5.1V: 8A (PB50); 10A (PB72); 13A (PB75, PC75, PH75)

• 24V: 2.5A (PB50); 2.8A (others)

Weight/Dimensions: Similar to AC series Chassis Compatibility: A, B, C (left-side mount)

3. ControlLogix-XT (Extreme Temperature) Power Supplies

Models: AC - PAXT, PA30XT; DC - PBXT, PB30XT Temperature Range: -25°C to 70°C

Input Ranges:

• AC: 85–265V @ 47–63 Hz

• DC: 18–32V (Nominal 24V)

Power Ratings:

• Output: 30–52W depending on model

• Inrush: 20A (AC); 30A (DC)

Current Output (DC):

• 1.2V: 1.5A

• 3.3V: 2A (PA30XT/PB30XT); 4A (PAXT/PBXT)

• 5.1V: 6A (PA30XT/PB30XT); 8A (PAXT); 10A (PBXT)

• 24V: 1.25A (PA30XT/PB30XT); 1.75A (PAXT); 2.1A (PBXT)

Compatibility: XT chassis (e.g., A4LXT, A7XT, A10XT) Wire Size: 2.5mm² copper
Weight: 0.77kg (PA30XT/PB30XT); 0.95kg (PAXT/PBXT)

4. Redundant Power Supplies

Models: PA75R, PA75RK (AC); PB75R, PB75RK (DC)

Features:

• Supports redundant pairs

• Load sharing via chassis

• Built-in diagnostic/status indicators

• System recognition via input module

Input Voltage:

• AC: 85–265V AC @ 50/60Hz

• DC: 18–32V DC (Nominal 24V)

Output Power: 75W
Hold Up Time: 2 cycles (AC); 20ms (DC)
Inrush Current: 20A (AC); 30A (DC)
Annunciator: 240V AC/DC @ 50mA (AC models); 90V DC (DC models)

Current Output (DC):

• 1.2V: 1.5A

• 3.3V: 4A

• 5.1V: 13A

• 24V: 2.8A

Weight: 1.45kg
Dimensions: 17.5 x 14.5 x 13.7 cm
Wire Size: 2.5mm² (Power); 0.25–2.5mm² (Annunciator)

5. ControlLogix-XT Redundant Power Supplies

Models: PAXTR (AC); PBXTR (DC)
Temperature Range: -25°C to 70°C

Power Specs:

• Input: 75VA 65W (PAXTR); 81W (PBXTR)

• Output: 42W (PAXTR); 52W (PBXTR)

• Current Output: Same as standard redundant power supplies

• Dimensions, wire size, and annunciator ratings: Identical to non-XT redundant models

6. Environmental Ratings (All Models)

• Storage Temp: -40°C to 85°C

• Operating Temp: 0°C to 60°C (Standard); -25°C to 70°C (XT)

• Vibration: 2g, 10–500 Hz

• Shock: 30g (operating); 50g (non-operating)

• Immunity: ESD, surge, EFT/B, RF, voltage dips; XT AC models include damped oscillatory wave immunity

Need Help Selecting a ControlLogix Power Supply?

Contact PLG Automation for expert guidance on selecting and sourcing the right Allen-Bradley ControlLogix power supply for your application.

Contact Us:
📧 sales@plgautomation.com
📞 800-906-9271