Configured for internal DC backplane voltage conversion and field-side power distribution in CompactLogix controllers, the Allen-Bradley 1769-PB4 (1769-PB4 Power Supply) provides direct physical/electrical execution.
Hardware Specifications
Parameter
Specification
Model
1769-PB4
Brand
Allen-Bradley
Origin
USA / Global Manufacturing standard
Weight
1.00 lbs (0.45 kg)
Dimensions
Standard 1769 Compact I/O expansion module form factor
CompactLogix I/O Density Scaling & Backplane Bus Power Integration
The 1769-PB4 connects to the 1769 expansion rail to deliver regulated internal logic power, supporting high I/O density scaling across adjacent digital and analog modules. By converting incoming 19.2-31.2 VDC field power to stable internal bus potentials, it ensures consistent operation of localized module logic without causing backplane bus communication velocity degradation across the CompactLogix system.
Frequently Asked Questions
Q: Can the 1769-PB4 power supply module be replaced under load while the CompactLogix backplane is active?
A: No, hot-swapping power supplies on the 1769 backplane is not supported. Disconnect incoming 24 VDC supply power before removing or installing the module to prevent electrical arcing or logic disruption.
Q: How does the module handle high inrush current during initial power-up?
A: The internal circuitry of the 1769-PB4 accommodates an inrush current rating up to 30 A, preventing false tripping of upstream DC power sources during cold startup cycles.
Field Installation Guidelines
Isolate and lock out incoming 19.2-31.2 VDC field power before mounting the module to the CompactLogix assembly.
Align the tongue-and-groove side connectors of the 1769-PB4 with adjacent 1769 I/O modules or controller housing.
Slide the module onto the DIN rail until the locking lever snaps securely into place.
Connect incoming DC power leads to the designated screw terminals, ensuring correct wire gauge and polarity verification.
Secure the field wiring cover and verify functional output status via front panel LED diagnostics upon re-energization.
