Name: Omron 61F-11 Floatless Level Switch Relay Unit - INOSAKI
SKU: Omron-61F-11
Price: 53.48 USD
Availability: InStock

Technical Overview

General-purpose 11-pin plug-in relay unit for floatless level controllers. Features 8 VAC electrode voltage, 1 mA current, and LED status indicator.

Key Features

Building-block plug-in design permits rapid replacement without disconnecting terminal field wiring [5.2.5].
Integrated LED operation indicator provides clear visual confirmation of the relay's operation status.
Conductive level-sensing technology eliminates moving parts, avoiding failures caused by float jam, rust, or fouling.
Low inter-electrode voltage of 8 VAC and current of approximately 1 mA prevent electrode oxidation and electrolysis.
Fully compatible as an interchangeable replacement relay unit inside the standard 61F-G series basic controllers.
High mechanical and electrical durability with long life expectancy to ensure continuous operation.

Technical Specification Matrix

Parameter	Value
Type of Product	Floatless Level Controller Relay Unit
Inter-Electrode Voltage	8 VAC
Inter-Electrode Current	Approx. 1 mA AC max.
Contact Ratings	5 A at 250 VAC (Resistive load); 1 A at 250 VAC (Inductive load)
Power Consumption	Approx. 3.2 VA max.
Operating Temperature Range	-10 to +55°C
Operating Humidity Range	45% to 85% RH
Response Time	Operate: 80 ms max.; Release: 160 ms max.
Mechanical Life Expectancy	5,000,000 operations min.
Electrical Life Expectancy	100,000 operations min.
Connection Pins	11-pin plug-in design
Maximum Wiring Distance	1 km max. (using standard 600-V, 3-conductor cabtire cable)
Physical Weight (kg)	0.1
Dimensions L x W x H (cm)	8.4 x 3.8 x 4.94

Industrial Applications

1. Municipal Water Tower Automated Supply Control

Automating the water supply of elevated municipal water towers. By installing the 61F-11 inside a standard 61F-G controller, three electrodes of varying lengths (common, low-level pump start, high-level pump stop) are suspended in the reservoir. When the water level falls below the medium electrode, the 61F-11 triggers the supply pump via its 5A contact rating until water reaches the short electrode, where it then switches off.

Problem Solved

Eliminates traditional mechanical float switch issues such as physical jams, mineral encrustation, and structural corrosion, resulting in a maintenance-free, high-reliability autonomous supply loop.

Conductive level sensing8 VAC inter-electrode voltageAutomatic water supplyPF113A SocketSelf-holding circuit

2. Industrial Wastewater Sump Automatic Drainage

Controlling heavy-duty drainage pumps in industrial sumps to prevent liquid overflow. As wastewater rises and bridges the gap to the highest electrode, the 61F-11 energizes its internal relay to activate drainage pumps. Once the liquid level drops below the lower boundary electrode, the relay de-energizes, shutting down the pump to avoid dry-running.

Problem Solved

Prevents hazardous wastewater overflows and floor flooding. Conductivity-based detection operates reliably even in highly turbulent, dirty, or contaminated water where optical, ultrasonic, or mechanical float sensors are prone to fouling and failure.

Wastewater drainageConductive level controlRelay contact output11-pin plug-in relayElectrode holder

3. Agricultural Irrigation Sump Dry-Run Protection

Protecting submersible irrigation pumps from dry-running in deep wells or suction sumps. By deploying the 61F-11 in a 61F-G1 controller configuration, an additional low-level alarm electrode is monitored. If water falls below the safe minimum suction level, the relay de-energizes immediately (within an 80 ms response time), tripping the pump contactor and preventing operation without fluid.

Problem Solved

Eliminates pump motor burnout and impeller damage caused by dry-run thermal and mechanical stress, securing high-cost agricultural pumping infrastructure against water source depletion.

Idling preventionDry-run protectionLow-level alarm80 ms response timeConductive level detection