Miselli XLV Series Electrical Level Indicator – NC Contacts – Changeover

Description

Operating Principle

The Miselli XLV Series Electrical Level Indicator – NC Contacts – Changeover provides dual functionality in hydraulic systems: direct visual monitoring of the fluid level and an automated electrical signal. The system operates באמצעות a technopolymer float equipped with an internal magnetic element. When the float reaches the preset minimum level threshold defined during design, the REED sensor is activated, generating an electrical contact used for system control logic. Versions equipped with a temperature sensor operate in a complementary way, opening or closing the electrical circuit when a preset temperature limit is reached, thus ensuring additional thermal protection for the entire system.

Construction Features

The structure of this component is designed to ensure both robustness and high readability. The indicator consists of an internal transparent tube made of high-resistance polycarbonate (PC). This sensitive visual component is protected by an external aluminum shield, which provides essential mechanical protection against impacts while maintaining side visibility of the fluid level inside the tank. The fastening systems (screws and nuts) are standardized in M12 size and made of white zinc-plated steel. For hydraulic sealing, the indicator uses standard NBR 70 Shore gaskets. The devices feature standardized center distances for mounting at 300 mm, 400 mm, and 500 mm; however, custom dimensions can be requested according to specific tank geometry requirements.

Available Variants and Options

The entire series includes various technical configurations to meet multiple system requirements. Models are mainly divided according to the type of electrical contact for the minimum level sensor:

• XLV/SL-NC: Base model equipped with a Normally Closed (NC) minimum level sensor.
• XLV/SL-EX: Model equipped with a changeover-type minimum level sensor.
• XLV/SL-NC-ST and XLV/SL-EX-ST: Advanced versions integrating a maximum temperature sensor directly within the lower fixing screw.

Regarding the temperature sensor (ST), it is made of zinc-plated steel with M12 threading, features IP65 protection against external agents, and is equipped with an adjustable DIN connector for easier wiring. It can be factory-set at 60°C or 70°C and configured with either Normally Open (NO) or Normally Closed (NC) contact depending on the control panel logic.

Additionally, for harsh environment applications, further options are available: stainless steel screws and nuts (only for -SL series models), FKM (VITON®) sealing gaskets for aggressive fluids, and the possibility of installing up to 2 REED sensors on the same indicator. The level sensor is always supplied with a 250 cm free connection cable.

Fluid Specifications and Operating Parameters

From an operational standpoint, the component is suitable for use in hydraulic circuits with a maximum working pressure of 1 bar. The recommended maximum operating temperature is 80°C. The device offers full and tested chemical compatibility with mineral oils, synthetic oils, general hydraulic fluids, and fluids containing glycol. However, it has limited resistance to hydrocarbons such as gasoline and diesel, a factor that must be carefully considered during design and material selection.

Installation Instructions

Installation on the tank can be carried out in two different ways depending on accessibility:

• External tank mounting: Two M12 threaded holes must be made at the required center distance, ensuring a tolerance of +0.5 mm for proper alignment.
• Internal tank mounting: Requires two through holes with a diameter of 12.5 mm (-0.2) and the mandatory use of the supplied flanged nut. In both configurations, to avoid damaging the seals and the polycarbonate body, the maximum recommended tightening torque must not exceed 5 Nm.

Technical Summary Table

Technical summary of the main characteristics of the Miselli XLV Series Electrical Level Indicator – NC Contacts – Changeover.