Set your multimeter to DC microamps (µA)

The robust construction allows it to withstand the thermal stress of repeated heating cycles in both residential and light commercial HVAC applications

the 5151-045BX ensures proper head pressure management and optimized heat transfer across the condenser coil

It is the direct official replacement for the discontinued Aaon OE392-10

and start terminals

Aprilaire 4740 Relay 320734-701 Set your multimeter to DCThe Aprilaire 4740 Relay is a critical replacement component engineered specifically for Aprilaire 700 series humidifiers, including the 700A and 700M models manufactured after 2008. As a genuine AprilAire humidifier part, this fan relay is responsible for powering the circulator fan when the humidistat signals for moisture. Unlike older "Series One" versions that utilized the 4238 control board with an integrated transformer, this modern 24V