Series 20 — Extended Stem Hardware
Series 20 Extended Stem Hardware provides the mechanical and electrical infrastructure for mounting liquid level switches at extended stem lengths. The system includes control heads with factory-sealed relay compartments, relay housing bodies, stem sets, and associated hardware. Control heads accept 20-726 stem sets fastened with set screws; all stem/head interfaces are O-ring sealed for rain-tight service. Available in 120V and 240V configurations.
20-725 — Control Heads
The 20-725 control head houses a factory-sealed relay compartment with a 20A SPDT relay. O-ring sealed rain-tight construction with removable cap. Accepts 20-726 stem sets. Includes 20-903 connector set. Injection-molded fire-retardant ABS housing rated to 130°C.
20-725-HS — Relay Housing, O-Ring Seal + Set Screws
The 20-725-HS is the housing body for use when building or replacing the enclosure in a Series 20 extended stem installation. Features removable cap with O-ring seals at cap and base for rain-tight service. Accepts 20-726 stem sets fastened with four set screws; stem/head interface is O-ring sealed.
System Overview
The Series 20 extended stem system is designed for applications requiring the liquid level sensing element to be positioned at a distance from the control head. Key system features:
- Rain-tight construction: O-rings at cap and base on all 20-725 housings.
- Stem interface: All stems accept the 20-726 stem set, fastened with four set screws; interface is O-ring sealed.
- Relay options: 120V (3/4 HP) or 240V (1-1/2 HP), both 20A SPDT.
- Switch function flexibility: Supports on/off at selected level, wide/narrow differential, alarm at extremes, no stop, and no start configurations.
- Connector: 20-903 connector set included with control heads.