1747-L40

The Allen-Bradley 1747-L40 is a processor with an instruction capacity of 1,024 (1K) words and a typical scan time of 8 milliseconds per 1K words. This module is geared up with a power supply and a fixed number of I/O contained in 1 package. The memory type is a capacitor-backed RAM memory. The 1747-L40 has a working temperature of 32-140 °F and a storage temperature from -40-185 °F at 5-95% relative humidity without condensation. For most applications, regular convection cooling will keep the controlling additives within the working temperature range. The precise factor spacing inside the enclosure is normally enough for heat dissipation. In a few applications, a massive quantity of heat is generated by means of a different system inside or outside the enclosure. In this case, place the blower fan inside the enclosure to aid air circulation and to reduce the hot spots near the controller. Additional cooling methods may be required when high ambient temperatures are encountered.

The 1747-L40 has the power supply inrush rating of 40A and a Bit execution time of 4 milliseconds. The maximum power requirement of this module is 50 VA and a wire size of 14 AWG. The main power breaker switch should be placed where the operator and maintenance personnel have quick and easy access to it. Ideally, the breaker switch should be installed on the outside of the enclosure, so that it can be accessed without opening the lid.