Allen-Bradley 1756-PB75 ControlLogix DC Power Supply
Configured for internal backplane bus power distribution in Allen-Bradley ControlLogix 1756 chassis, the Allen-Bradley 1756-PB75 (1756-PB75 Chassis Power Supply) provides direct physical/electrical execution. The module converts an incoming 18-32 VDC nominal source (24 VDC nominal) into regulated internal logic voltages, delivering up to 95 W total output power directly to the chassis backplane. It mounts directly into the left end slot of the ControlLogix rack, supplying operational DC current to local CPU processors, communication interfaces, and discrete/analog I/O cards.
Hardware Specifications
| Parameter | Specification |
|---|---|
| Model | 1756-PB75 |
| Brand | Allen-Bradley |
| Origin | USA |
| Weight | 2.16 lbs (0.98 kg) |
| Dimensions | 5.5 in x 4.4 in x 5.7 in (14.0 cm x 11.2 cm x 14.5 cm) |
| Operating Temp | 0 to 60 deg C (32 to 140 deg F) |
| Power Consumption | 95 W Maximum Output Power |
| Input Voltage Range | 18 to 32 VDC |
| Nominal Input Voltage | 24 VDC |
| Module Type | Standard Chassis Power Supply |
| Compatible System | Allen-Bradley ControlLogix 1756 Chassis |
Backplane Bus Communication & Deterministic Processing
The Allen-Bradley 1756-PB75 stabilizes internal DC bus voltages to preserve backplane bus communication velocity across high-density I/O configurations. By delivering clean, regulated power across the 1756 backplane lines, the supply prevents transient voltage dips from interrupting EtherNet/IP deterministic networks and processor block transfers. Onboard overcurrent and overvoltage protection circuits ensure firmware flash compatibility and logic state stability across connected control and communication modules during power switching sequences.
Frequently Asked Questions
Q: Can the 1756-PB75 power supply be installed in any available slot of a ControlLogix chassis?
A: No. The 1756-PB75 is physically designed to mount exclusively into the left end power supply slot of a 1756 ControlLogix chassis to properly mate with the dedicated backplane power connector pins.
Q: What happens if the input voltage drops below the 18 VDC lower operating threshold?
A: If the input voltage drops below 18 VDC, the internal power monitoring circuitry initiates an orderly backplane shutdown signal to host controllers to prevent memory corruption and invalid output states before main DC output voltages collapse.
Field Installation Guidelines
- Power Isolation: Ensure the primary 24 VDC source power is fully isolated and switched off before attaching input wiring or mounting the 1756-PB75 module into the 1756 chassis.
- Chassis Mounting: Slide the power supply housing into the left side of the ControlLogix chassis until the top and bottom retaining levers snap securely onto the chassis tabs.
- Wiring & Terminal Connections: Connect the incoming 24 VDC source lines (DC+, DC-) and functional ground to the removable terminal block using 14 AWG copper wire. Tighten terminal block screws to the specified torque.
- Grounding Integrity: Connect a heavy-gauge protective earth (PE) grounding conductor directly from the chassis grounding lug to the main enclosure backplate ground bus bar to optimize electromagnetic immunity and surge suppression limits.
Allen-Bradley 1756-PB75 ControlLogix DC Power Supply
Allen-Bradley 1756-PB75 ControlLogix DC Power Supply
Configured for internal backplane bus power distribution in Allen-Bradley ControlLogix 1756 chassis, the Allen-Bradley 1756-PB75 (1756-PB75 Chassis Power Supply) provides direct physical/electrical execution. The module converts an incoming 18-32 VDC nominal source (24 VDC nominal) into regulated internal logic voltages, delivering up to 95 W total output power directly to the chassis backplane. It mounts directly into the left end slot of the ControlLogix rack, supplying operational DC current to local CPU processors, communication interfaces, and discrete/analog I/O cards.
Hardware Specifications
| Parameter | Specification |
|---|---|
| Model | 1756-PB75 |
| Brand | Allen-Bradley |
| Origin | USA |
| Weight | 2.16 lbs (0.98 kg) |
| Dimensions | 5.5 in x 4.4 in x 5.7 in (14.0 cm x 11.2 cm x 14.5 cm) |
| Operating Temp | 0 to 60 deg C (32 to 140 deg F) |
| Power Consumption | 95 W Maximum Output Power |
| Input Voltage Range | 18 to 32 VDC |
| Nominal Input Voltage | 24 VDC |
| Module Type | Standard Chassis Power Supply |
| Compatible System | Allen-Bradley ControlLogix 1756 Chassis |
Backplane Bus Communication & Deterministic Processing
The Allen-Bradley 1756-PB75 stabilizes internal DC bus voltages to preserve backplane bus communication velocity across high-density I/O configurations. By delivering clean, regulated power across the 1756 backplane lines, the supply prevents transient voltage dips from interrupting EtherNet/IP deterministic networks and processor block transfers. Onboard overcurrent and overvoltage protection circuits ensure firmware flash compatibility and logic state stability across connected control and communication modules during power switching sequences.
Frequently Asked Questions
Q: Can the 1756-PB75 power supply be installed in any available slot of a ControlLogix chassis?
A: No. The 1756-PB75 is physically designed to mount exclusively into the left end power supply slot of a 1756 ControlLogix chassis to properly mate with the dedicated backplane power connector pins.
Q: What happens if the input voltage drops below the 18 VDC lower operating threshold?
A: If the input voltage drops below 18 VDC, the internal power monitoring circuitry initiates an orderly backplane shutdown signal to host controllers to prevent memory corruption and invalid output states before main DC output voltages collapse.
Field Installation Guidelines
- Power Isolation: Ensure the primary 24 VDC source power is fully isolated and switched off before attaching input wiring or mounting the 1756-PB75 module into the 1756 chassis.
- Chassis Mounting: Slide the power supply housing into the left side of the ControlLogix chassis until the top and bottom retaining levers snap securely onto the chassis tabs.
- Wiring & Terminal Connections: Connect the incoming 24 VDC source lines (DC+, DC-) and functional ground to the removable terminal block using 14 AWG copper wire. Tighten terminal block screws to the specified torque.
- Grounding Integrity: Connect a heavy-gauge protective earth (PE) grounding conductor directly from the chassis grounding lug to the main enclosure backplate ground bus bar to optimize electromagnetic immunity and surge suppression limits.
