ERECTA SWITCH® by Compac Engineering
Series 20 · ERECTA SWITCH®

20-725 — Control Head

Series 20 control head with factory-sealed 20A SPDT relay. Rain-tight O-ring sealed ABS enclosure. 1-1/4 NPT. Accepts 20-726 stem set.

20-725-120 Control Head

Configure & Order

Voltage
SKU: 20-725-120
Qty
In stock · Ships Wednesday · Made in Paradise, CA · No minimum order
Net Price — per unit (120V (3/4 HP))
QuantityPrice
1–2$190.95
3–4$162.33
5–9$137.48
10+$95.47
As low as $95.47 · OEM pricing quoted upon request.

Product Description

The 20-725-120 is the 120V Series 20 control head. Houses a factory-sealed 20A SPDT relay rated for 3/4 HP motor service at 120V. Rain-tight O-ring sealed ABS enclosure with wire connection chamber. Accepts 20-726 stem set secured with four set screws. Includes 20-903 connector set.

SpecificationValue
Relay20A SPDT, factory sealed
Connection1-1/4 NPT
Conduit1/2 in
Connector Pins3 (included — 20-903 connector set)
Set Screws4×
Diameter3.0 in (76.2 mm)
Length5.85 in (148.59 mm)
MaterialInjection-molded ABS, fire retardant
SealO-ring at cap and base, rain-tight
Ambient Temp130°C max
PressureAtmospheric

What Makes the 20-725 the Right Choice

Factory-sealed relay compartment
20A SPDT relay sealed from the wire connection chamber. Rain-tight enclosure with O-rings at cap and base.
Multiple control schemes
On/off at selected level, wide differential, narrow differential, no stop, alarm at extremes, no start. Refer to SCE-400 wiring diagrams.
120V and 240V versions
120V version rated 3/4 HP. 240V version rated 1-1/2 HP. Select voltage to match your motor or load. Both include 20-903 connector set.
Rain-tight ABS enclosure
Injection-molded fire-retardant ABS rated to 130°C ambient. O-ring sealed cap and base. Removable cap for field wiring access. Suitable for outdoor and washdown installations.
ERECTA SWITCH modular architecture
Every component is independently field-replaceable. Snap-and-screw modular design enables part-level replacement in minutes without factory return.
RoHS compliant · Made in USA
Manufactured in Paradise, California. RoHS compliant throughout. No minimum order.

Where the 20-725-120 Is Specified

Frequently Asked Questions

Common Questions About This Product

What is the difference between a float level switch and a liquid level sensor?

A float level switch like the 20-725 is a point-level device: a float rides the liquid and actuates a magnetic reed switch at a set height, giving a simple on/off signal — no power, no firmware, no calibration. "Sensors" usually means continuous measurement (ultrasonic, radar, capacitive). ERECTA SWITCH targets reliable discrete-point control.

What factors should I consider when choosing the 20-725?

Consider media chemistry (pick PP, AC, or KR), liquid specific gravity, operating temperature and pressure, mounting style, number of switch points, and electrical contact rating. Compac will spec it from your application — request a free evaluation sample.

What liquid chemistries is the 20-725 compatible with?

Choose the material to match the media: Polypropylene (PP) for general aqueous, acids, and bases; Acetal (AC/Delrin) for solvents, fuels, and hydrocarbons; Kynar PVDF (KR) for aggressive or harsh chemicals. Most ERECTA SWITCH models are offered in all three materials; some are material-specific, so check the product page for the model you need.

What mounting options are available for the 20-725?

ERECTA SWITCH offers vertical top-mount, bulkhead, and extended-stem configurations, plus side-mounted single-point models. The mount style is part of the model number — select the configuration that matches your tank geometry.

How is the actuation level set on the 20-725, and how accurate is it?

Point detection is repeatable and mechanical. The trip height on the 20-725 is set by the 10-715 Precision Nipple, ordered separately in 1-inch increments (1″–70″), so you place the switch point exactly where the application needs it.

What pressure and temperature can the 20-725 handle?

It depends on the series, and the derate matters more than the headline. Series 10 is rated 100 PSI, Series 15 50 PSI and Series 20 20 PSI — each at 20°C, each derating to zero at 90°C, so a hot line has no pressure allowance left. Series 20 sits lowest by design: its float sections are thin-walled, and sustained pressure can crush them. Temperature follows the material — on Series 10, PP: 180°F, AC: 200°F, KR: 280°F.

Can one 20-725 switch control both a high and a low level?

A single switch detects one point. For high-plus-low detection (or more), use a multi-level extended-stem set that places multiple reed points on one stem, giving you independent high and low signals from a single mounting hole.

How do I wire the 20-725 to a pump or alarm?

The 20-725 uses a magnetic reed switch wired in series with your relay or controller. Contact rating is 70 VA / 50 W resistive (UL File E70063). The switch ships with lead wires — connect directly to your control circuit.

Does the 20-725 need calibration?

No. The 20-725 is a mechanical float actuating a sealed reed switch — there is nothing to calibrate or power. This is a reliability advantage over electronic sensors that can drift over time.

How do I maintain the 20-725, and what if it stops working?

Inspect that the float moves freely (check for debris or scaling), then test reed continuity with a multimeter. Because ERECTA SWITCH is modular, you replace only the individual component — switch, float, connector, or fitting — instead of the whole assembly.

Is the 20-725 safe for flammable or hazardous-area liquids?

Standard ERECTA SWITCH models are not rated for hazardous (Class I / Div) areas. For flammable-service applications, contact Compac engineering to discuss your requirements and available options.

What are the typical applications for the 20-725?

The 20-725 is used for pump start/stop control, high-level overflow protection, low-level dry-run protection, and tank or reservoir level alarms in OEM equipment. The modular ERECTA SWITCH system is built into laundry, HVAC, water-treatment, hydraulic, and chemical-handling machinery.

What makes ERECTA SWITCH different from other switches?

It is the only fully modular, off-the-shelf liquid level switch system: switch, float, connector, fitting, and nipple are independently field-replaceable and stocked. OEMs configure exactly what they need with no minimums and short lead times. Made in Paradise, California; RoHS compliant.

Questions About This Product?

Our engineering team can verify compatibility with your application and chemistry before you order.