LL051 Level Controller

LL051 Level Controller

Code: LL051



Product Description


LL051 Level Controller

The LL051 liquid level controllers provide high-level, low-level, or bilevel control in a convenient octal plug-in package. Models are available for pump-up or pump-down operation. Transformer isolated AC voltage on the probes prevents electrolytic plating. Less than 1/1000 of an ampere of current is used to sense the presence of conductive liquid between the probes and common. Onboard sensitivity-adjustable units eliminate false tripping caused by floating debris and foaming agents. Isolated electromechanical relay contacts can be directly connected to the control circuitry or control pumps and solenoids. The LL051 controllers can be used at a distance of up to 500ft from probes, and twisted-pair or shielded cable is recommended.


  • Dual probe level detection.
  • Solid state circuitry, coated for moisture protection.
  • Factory-fixed or adjustable sense resistance.
  • UL and CSA approvals.
  • Electromechanical relay output for isolation and reliability.

Download LL051 Level Controller Product Sheet (.pdf, 29KB)


LL051 General Purpose Relay
Sensing Type
ON/OFF Resistance
Voltage at Probe Terminals
12 VAC nominal

Sensing Resistance

Factory-fixed or adjustable to 100,000 ohms
Sensing Resistance Tolerance

Factory-fixed - ±10%;
adjustable - guaranteed range

24, 120, or 230 VAC
±15% nominal
50/60 Hz
Output Type
Electromechanical Relay
SPDT isolated
Output Contact Ratings
(1-3 or 1-4)
5A @ 220 VAC
10A @ 120 VAC
10A @ 30 VDC
Socket Rating
10A @ 300 VAC
Controller Dimensions
1.75" x 2.375" x 2.75"
(45mm x 61mm x 70mm)
Socket Dimensions
1.5625" x 2" x .6875"
(40mm x 51mm x 18mm)
Total Installed Height
Transient Protection
Dielectric Breakdown: 1500V RMS Minimum
-20°C to 60°C Operating Temperature
(-4°F to 140°F)