Lennox part number 16D74, catalog number 105241-01, is a factory-specified time delay relay used in Lennox HVAC systems for controlled sequencing of electrical components. This component is manufactured by Littelfuse under the SSAC series and is approved for use in OEM and replacement applications where precise timing control is required.

Product Overview
The Lennox 16D74 Littlefuse SSAC CT1S45 timer provides both delay-on-make and delay-on-break functionality in a compact, solid-state design. Operating on 24 VAC control voltage, it introduces a 1-second delay when energized and a 45-second delay when de-energized. This controlled timing helps prevent short cycling, protects system components, and ensures smooth operation of HVAC equipment such as blowers, compressors, and control circuits. The solid-state construction offers reliable performance with no moving parts, making it well suited for continuous HVAC duty.

 

Specifications:

Manufacturer: Littelfuse
Series: SSAC
Model: CT1S45
Lennox Part Number: 16D74
Lennox Catalog Number: 105241-01
Control Voltage: 24 VAC
Function: Delay-On-Make / Delay-On-Break
Delay-On-Make: 1 second
Delay-On-Break: 45 seconds
Maximum Load Current: 0.75 Amp
Mounting Style: Plug-in / panel mount (application dependent)
Application: HVAC control timing and sequencing