HB Products

Manual for rigid level sensors and controllers

Covers: HBLC, HBLT, HBSLC & HBSLT

For analog measurements of liquids like NH3, water, HFC/HFO refrigerants, CO2, Hydrocarbons and alcohols. Can be used in refrigeration systems and similar demanding systems.

[ATEX/Ex] versions included

Introduction

HBLC, HBLT, HBSLC and HBSLT are intelligent liquid level sensors designed for installation in vessels or standpipes. The HBLC and HBSLC models measure directly between the sensor element and the vessel/standpipe, while HBLT and HBSLT models feature an external pipe measuring between an inner rod and an outer pipe. Installation and configuration are similar for all types, and they share electronic heads. These sensors are suitable for refrigeration systems and other demanding applications involving high pressures and aggressive fluids. Versions are available with or without a cable for direct valve control. All models emit a 4-20mA analog signal proportional to the liquid level via an M12 plug. Special versions include a controller for direct valve control without a PLC.

Safety Instructions

CAUTION! Always read the instruction manual before commencing work! Installation requires technical knowledge of refrigeration and electronics. Only qualified personnel should work with the product and be aware of the consequences of improper installation, adhering to local legislation.

Modifications to type-approved equipment void its approval. Connect products and accessories only as shown in this guide. HB Products is not responsible for damages from non-adherence.

Explanation of safety symbols:

• ⚠️ CAUTION! Refers to a possible limitation of functionality or risk in usage.
• ? NOTE! Contains important information about the product and provides further tips.

The person responsible for operation must commit to adhering to all legislative requirements, preventing accidents, and avoiding damage to people and materials.

Intended use, conditions of use

The level sensor is designed for continuous liquid measurement. The sensor design and setup must comply with the liquid being measured. The table below indicates product compliance with various liquids. Use in refrigeration systems and similar environments is supported. Prior approval from HB Products is required for any other use or if the operation is determined to be problematic.

Disposal instructions: The sensor is constructed so modules can be easily removed and sorted for disposal.

Application Examples

HBLC and HBSLC

HBLC sensors feature a PTFE-covered rod and require an electrical connection to the overflow pipe or installation pipe. They are sensitive to turbulent conditions but can maintain control with high filter times. Their simple design is less prone to contamination than HBLT.

An HBSLC sensor connected to a modulating valve is shown as an alternative to low-pressure float control.

A diagram illustrates an economiser with an HBSLC connected to a Siemens MVS661 modulating valve.

HBLT and HBSLT

HBLT and HBSLT sensors are designed for liquid level measurement, typically used in chillers, pump separators, coolers, and condensers. They can be mounted in vessels, containers, and standpipes without an external pipe.

HBSLT/C: Sensor with integrated cable for direct control of 4-20 mA controlled modulating valves (e.g., Siemens MVS-series, Danfoss ICM-series). Includes LED display.

HBSLT/S: Sensor with integrated cable for direct control of stepper motor valves. This version lacks an LED display.

Installation notes for HBLT/HBSLT include:

• Standpipes should be insulated to reduce boiling.
• A minimum of 50 mm clearance is required between the sensor end and the bottom of the pipe.
• Drain pipes should be angled 5-10° to prevent oil pockets, which cause inaccurate measurements.

Diagrams show level sensors installed directly in a vessel and in a standpipe connected to a receiver.

Installation Instructions

Mount the sensor rod in a standpipe or vessel using the appropriate thread connection. Liquid sealant is used for sensors without an outer pipe and with NPT threads. A washer is used for BSPP threads. Teflon tape is suitable for versions with an outer pipe.

CAUTION! For welding work on the unit, remove the electronic head or ensure proper earthing to prevent damage to electronics.

Mounting instruction

The electronic head is mounted/demounted using three screws or a union. The threaded union is primarily for low-temperature applications. Tighten the union firmly for good electrical contact.

Sealant/Tape Usage:

• Liquid sealant: For HBLC and HBSLC sensors without an outer pipe.
• Teflon tape: For HBLT and HBSLT sensors with an outer pipe.

Mount the sensor on the vessel with a torque of 80-150 Nm.

How to connect the sensor

Three sensor types are available:

• Simple version: 4-20 mA output, simple setup. Connects via circular head with ISO4400/DIN43650 connector.
• Advanced version: 4-20 mA output, advanced setup, LED indicators, optional display. Connects via large head with M12 EN61076-2 connector, with or without display/output cable.
• Controller sensor: Analog output, advanced setup, display, LED indicators, valve control. Connects via M12, can be directly connected to a valve.

The M12 connection is used for power supply. Some versions can control a valve directly via a cable.

Connection diagrams

Simple sensor

Suited for sensors with a simple electronic head.

Pinout:

• 1: +24V DC or AC
• 2: - Common
• 3: AO, 4-20 mA level
• 4: Communication only (for setup and calibration)

Diagram shows connection to a PLC.

Sensors without control cable

Suited for HBLC, HBLT, and HBLT-wire.

Pinout:

• 1: +24V DC or AC
• 2: - Common
• 3: DO, Alarm output
• 4: AO, 4-20 mA level
• 5: Communication only

Diagram shows connection to a PLC. A note indicates that digital output on pin 3 is an alarm output, and remote setpoint is not available for these versions.

M12 Cable, wire Colour: 1=Brown, 2=White, 3=Blue, 4=Black, 5=Gray.

Sensors with control cable for stepper motor valves (e.g., Carel E2V)

Suited for HBSLT/S, HBSLT-wire/S, HBSLC/S.

Pinout:

• 1: +24V DC or AC
• 2: - Common
• 3: AI Remote set point 4-20 mA
• 4: AO, 4-20 mA level
• 5: Run in signal

Diagram shows connection to a PLC. Note: Sensor is powered via M12 plug only.

Color coding for stepper motor valve connections: A+=yellow(2), A-=white(4), B-=green(1), B+=brown(3).

The sensor has a built-in controller for stepper valves. Analog output via cable controls the valve; level signal to PLC via M12 plug. Pin 3 accepts a 4-20 mA signal for setpoint changes. A special menu is activated in the HB-tool for stepper motor setup.

Sensors with control cable for pulse modulating valve (e.g., Danfoss AKV/AKVA)

Suited for HBSLT/PWM, HBSLT-wire/PWM, HBSLC/PWM.

Pinout: (Same as stepper motor valves: 1=+24V, 2=Common, 3=AI Remote Setpoint, 4=AO, 5=Run in signal)

Diagram shows connection to a PLC. Note: Sensor is powered via M12 plug only.

The sensor has a built-in controller for pulse modulating valves. Analog output via cable controls the valve; level signal to PLC via M12 plug. Pin 3 accepts a 4-20 mA signal for setpoint changes.

Wiring using cable: Brown: + when using DC; White: - common when using DC. Cable can supply AC.

Sensors with control cable for modulating valve (e.g., Siemens MVS661)

Suited for HBSLT/C, HBSLT-wire/C, HBLC/C.

MVS661 Motor Valve Connections:

• G0: -common
• G: + supply
• Y: mA input
• M: mA output position
• U: Open/Close valve
• ZC: Manual open/close

Sensor M12 Pinout: (Same as stepper motor valves: 1=+24V, 2=Common, 3=AI Remote Setpoint, 4=AO, 5=Run in signal)

Diagram shows connection to a PLC. Note: Sensor is powered via M12 plug only.

The sensor has a built-in controller for pulse modulating valves. Analog output via cable controls the valve; level signal to PLC via M12 plug. Pin 3 accepts a 4-20 mA signal for setpoint changes.

Sensors with EX approval and two wire connection

Suited for HBLT, HBLT-wire, HBLC.

Pinout:

• 1: +24V DC
• 2: Not used
• 3: Not used
• 4: AO, 4-20 mA level
• 5: Not used

Diagram shows connection via a barrier to a PLC. The sensor with ATEX approval uses a two-wire connection, with pins 1 and 4 active for a 4-20 mA analog signal.

Scaling and offsetting the output

Scaling the analog output

The output is scaled linearly from minimum to maximum using the HB-tool.

Offsetting minimum and maximum

If the sensor height does not match the vessel height, the minimum and maximum levels can be adjusted beyond the physical sensor using offset values in the HB-tool. Calibration to known levels is also possible.

A graph illustrates the analog output (mA) versus level, showing minimum and maximum levels.

Setting up the sensor

Sensors are delivered pre-calibrated for the specified liquid. Simple setup involves filter time and calibration using a simple tool. Advanced sensors offer multiple parameters.

Connection to a PC is via a USB/M12 cable. A simple sensor may require an additional adapter. The HB-tool is downloaded from the HBproducts web page.

Setup using a splitter box

A splitter box allows running the refrigeration system and connecting a PC simultaneously. It is intended for installation and modification, not normal operation. It connects to the HBX sensor's M12 plug, allowing connection to both the PC and the normal M12 plug.

Use the HB tool for setting up the sensor

Simple versions only

The HB tool for simple versions is basic, primarily allowing filter time adjustment. Calibration is similar to advanced versions.

A screenshot shows the HB-tool interface with options for communication settings, level sensor settings (filter time), and calibration (zero, span, actual measurement).

Advanced versions only

The sensor can operate in two modes: as a sensor input to a PLC/computer or in control mode.

The HB tool has three pages of settings (Basic, Advanced, Diagnostic). Fields may be greyed out depending on the chosen setting. Detailed explanations appear on mouse-over (in the tool itself). Changes are saved by clicking "Save to sensor".

Screenshots illustrate the HB-tool configuration for HBLC and HBLT-Wire, showing various settings like control/level mode, setpoint, P-band, alarm settings, and mechanical type selection.

Basic settings

This section covers primary sensor settings.

• Filter time: Averages output to reduce fluctuations.
• Control function parameters: Settings for valve control, including "Run in signal" (ON/OFF for continuous/conditional control).
• Sensor parameters: Mechanical type, refrigerant, measurement length.
• Alarm level: For versions without valve control cable.
• Minimum and maximum adjustment: For sensor length adjustment.
• Remote setpoint selection.

Detailed explanations are provided for:

• Setpoint level in % (control mode only): Desired level percentage.
• P-band in % (control mode only): Control area describing valve opening based on deviation from the desired level.
• Filter time const. in sec.: Averages measurement over a programmable time span.
• Run in signal remote activation: Enables centralized control; if OFF, sensor control function is active.
• Zero & span cal. Function: Enables sensor calibration.
• Alarm setting in %: Desired alarm level as a percentage of max range.
• Alarm delay in sec: Delay before alarm is triggered.
• Offset max/min level in mm: Adjusts for sensor length relative to vessel height.
• Select mechanical type: Sensor type selection.
• Refrigerant: Type of refrigerant measured.
• Measurement length in mm: Sensor length.

Advanced settings

This section covers advanced sensor settings.

• Alarm function parameters: For sensors without a cable. Includes high/low alarm, hysteresis, relay function (NO/NC), and LED indication.
• Valve control parameters: Includes output direction (LP/HP mode), set mA or digital 2 output, digital 2 alarm setpoint, digital hysteresis, and maximum valve opening.

Output direction: LP-mode fills the container; HP-mode empties it. LP-mode = 4-20 mA; HP-mode = 20-4 mA.

A graph illustrates output direction (e.g., 25% Hysteresis, 55% at 80%, 100% at 0%).

Diagnostic (calibration of sensor)

Sensors are delivered pre-calibrated. For higher accuracy, calibration can be performed.

The diagnostic screen shows:

• Zero calibration: Normally calculated automatically.
• SPAN calibration: Normally calculated automatically.
• Actual measurement value.
• Visualization of control signal and level.

Buttons are available for "Zero calibration", "Calibrate known level" (between 1-100%), and "Send Zero/Span values".

LED indication

LED signals and their functions:

3-digit display: Shows 0-100% linearly corresponding to 4-20 mA (not available on /S stepper motor control version).

Calibration directly on the sensor (advanced versions only)

Calibration at 0% or 100% can be done independently. Calibration at 0% is recommended for high accuracy.

Note: "Zero & span cal. Function" in basic settings must be enabled (default is OFF).

Instruction for 0% calibration: Connect supply, empty vessel, activate "R" for 5 seconds (Yellow LED ON, then OFF), then activate "R" once (Yellow LED flashes once, Green LED confirms).

Instruction for 100% calibration: Fill vessel to 100%, activate "R" for 5 seconds (Yellow LED ON, then OFF), then activate "R" twice (Yellow LED flashes twice, Green LED confirms).

Fault detection

In case of a fault, replacing the electronic part is usually sufficient.

NOTE! Fault detection and/or changing the electronic function can be carried out without releasing pressure from the system or disassembling the mechanical part of the sensor.

Sensor Repair

In case of faults, replacing the electronics is typically necessary. Contact your local distributor for handling complaints.

Further Information

For further information, please visit www.hbproducts.dk, or send an email to: support@hbproducts.dk.

HB Products A/S – Bøgekildevej 21 – DK8361 Hasselager

Quick guide

Installation

Install the sensor in the vessel using liquid sealant or PTFE tape. Connect the electrical unit. Ensure the threaded union is firmly tightened for good electrical connection.

Setup

Sensors are delivered pre-calibrated for the specified liquid. For more accurate measurements, calibrate using the HB-tool, available for download from www.hbproducts.dk. A computer and USB/M12 cable are required.

Measurement signal

The sensor output is a 4-20mA signal on pin 4 of the M12 plug, linear to the level. Advanced wiring and valve control are described in the complete manual.

M12 Pinout:

• 1: +24V DC or AC
• 2: - Common
• 4: AO, 4-20 mA level

LED indication: When operating, the green LED should be on or flashing.