Description
The Allen-Bradley 1756-PA72 is a Standard Power Supply that is mainly used to deliver power to the backplane of a 1756 ControlLogix chassis, enabling each of module attached to the chassis to operate. The 1756-PA72 is designed to accept an input voltage range of 85-265 VAC with frequency range of 47-63 Hz. It delivers an output power of 75 W @ 0-60 °C (+32…+140 °F) with Current capacities of 4A at 3.3VDC; 10 A at 5.1VDC and 2.8 A at 24VDC.
The 1756-PA72 has a hold-up time of 5 cycles @ 85VAC, 50/60 Hz; 6 cycles @ 120VAC, 50/60 Hz; 6 cycles @ 200VAC, 50/60 Hz and 6 cycles @ 240V AC, 50/60 Hz. Hold-up time refers to the power supply’s reaction from the removal of the input voltage and DC power failure.
The 1756-PA72 is installed at the left most location of the chassis. It has a dedicated slot assignment, outside the chassis and does not occupy a ControlLogix slot. It may be installed in different ControlLogix chassis such as 1756-A4, 1756-A7, 1756-A10, 1756-A13, and 1756-A17, whether Series A, B and C. This power supply weighs approximately 0.95 kg (2.10 lb) with physical dimensions of 14.0 x 11.2 x 14.5 cm (5.51 x 4.41 x 5.71 in.). This module, along the ControlLogix chassis has an open-type enclosure, therefore, requires installation inside an enclosure that protects the hardware from industrial contaminants and interferences. The 1756-PA72 may not be used is redundant power supply applications however, it may also be used in Distributed I/O architecture.
The 1756-PA72 has a power consumption of 25 Watts at 0 to 60 degrees Celsius (32 to 140 degrees Fahrenheit). This power supply has a power dissipation of 85.3 BTU/hour and a power supply with a maximum inrush current of 20 A. The Allen-Bradley 1756-PA72 provides built-in overcurrent protection. It is user-supplied at a maximum of 15 A. The maximum transformer load of this power supply is 100VA and the voltage isolation is 250 Volts continuous. The 1756-PA72 also has a reinforced insulation type tested at 3500 Volts DC for 60 seconds. The Allen-Bradley 1756-PA72 is open type equipment. This power supply should be installed in an appropriate enclosure that is designed for certain environmental conditions. The inside of the enclosure should be accessible only with a tool. Please see the user manual from the NEMA Standard 250 and IEC 60529 publications for an explanation of the level of protection afforded by different types of enclosures.
