Current Sensing Relay 24 Volt for Humidifier Fan Activation

The Current Sensing Relay 24 Volt for Humidifier Fan Activation (P110-0050) provides a 24-volt control relay assembly used on Aprilaire 50 and compatible humidifier systems to detect blower amperage draw and energize the humidifier only when the furnace fan is operating. The relay measures approximately 3.5 inches high × 2 inches wide × 1.25 inches deep and incorporates an amperage-sensing coil, SPST low-voltage relay, and 24-volt control terminals. Rated for typical residential blower motor currents, the device prevents off-cycle humidifier operation, avoids duct condensation risk, and integrates cleanly with 24-volt humidifier circuits. Technicians use this relay as an OEM-approved fan-interlock solution when a G-signal is unavailable or when working with older furnaces. (electrical ratings: 24 VAC control, sensor coil approx. 1–20 A detection range)