EsiWelma Sensigas URD20SE - User Manual

EW0826D1_en – rev. A
CO
2
gas detectors – URD20SE
05/10/2020
Gas detection systems for industrial environments
1/8
Sensigas
®
Gas detectors
Carbon dioxide (CO
2
)
ATEX II 2G Ex d IIC T6 Gb certified
URD20SE
Sssssss
11…28Vdc power supply.
Nondispersive infrared (NDIR) sensor designed for the detection of carbon dioxide
(CO
2
).
Up to three alarm thresholds plus sensing element fail.
LED on sensing element body to indicate operating status.
Automatic countdown of sensor life.
Use
The URD20SE detectors are used to detect the presence of carbon dioxide (CO
2
), in
areas classified as Zone 1.
It detects carbon dioxide leaks or emissions in industrial environments, hospitals,
fermentation plants, greenhouses, stables and, more in general, where carbon dioxide
is stored, generated or produced.
URD20SE sensors can be used in stand-alone mode with 4…20mA output or with an
optional voltage-free contact relay card having the following four digital outputs:
Pre-alarm, 1
st
alarm threshold, 2
nd
alarm threshold, Sensor fail.
Operation
If there is a gas leakage, the detector compares the measured concentration value
with the threshold limit setpoints and energises the associated relays. Information on
the measured concentration value is always at the 4…20mA output.
Ordering
To order, simply state the part number: URD20SE.
For special versions, on request, please contact Customer Service.

Summary

Product Overview

Use

Describes where and why the detectors are used in industrial environments.

Operation

Explains how the detector functions during gas leakage and compares concentration values.

Ordering

Provides the part number for ordering the detector and contact for special versions.

Technical Characteristics

Installation Guidelines

Special Recommendations

Crucial safety advice regarding cover tightening and operational warnings.

Electrical Installation and Configuration

Terminal Board and Connections

Details on wiring terminals, jumper circuits, and connectors for setup.

Cabling and Output Configuration

Guidance on cable selection and 4-20mA output reference settings.

Operating Mode and Threshold Settings

Configuration of 4-20mA signal operating mode and alarm threshold values.

Optional Relay Card Installation

Relay Card Configuration and Testing

Relay Card Electrical Setup

Selecting contact types (NC/NO) and configuring relay operating mode.

Operational Checklist

Verifying sensor status, output, and LEDs after installation.

Maintenance and Support

Routine Maintenance and Decommissioning

Procedures for sensor testing, calibration, and safe decommissioning.

Warranty and Accessories

Information on product warranty, accessories, and dimensions/weight.

Marking Information and Installation Data

Key to Marking Information

Explanation of EC directives, ATEX markings, and certifications.

Installation and Routine Data Fields

Fields for recording installation site, product order, and routine checks.

Overview

1. Function Description
2. Important Technical Specifications
3. Usage Features
4. Maintenance Features

The EsiWelma URD20SE is a Sensigas® gas detector designed for the detection of carbon dioxide (CO2) in industrial environments. It is ATEX II 2G Ex d IIC T6 Gb certified, making it suitable for use in Zone 1 classified areas where explosive gas atmospheres may be present.

Function Description

The URD20SE utilizes a Nondispersive Infrared (NDIR) sensor to detect CO2 leaks or emissions. It operates on an 11-28Vdc power supply. The detector is capable of providing up to three alarm thresholds, in addition to indicating a sensing element failure. An integrated LED on the sensor body provides visual feedback on the operating status. The device also features an automatic countdown of the sensor's life.

The detector can operate in a stand-alone mode, providing a 4-20mA output signal proportional to the measured CO2 concentration. Alternatively, it can be expanded with an optional voltage-free contact relay card (UZR20.4) that offers four digital outputs: Pre-alarm, 1st alarm threshold, 2nd alarm threshold, and Sensor fail. When a gas leakage is detected, the device compares the measured concentration against predefined threshold setpoints and energizes the associated relays. The 4-20mA output continuously provides information on the measured concentration.

The URD20SE is particularly useful in industrial environments, hospitals, fermentation plants, greenhouses, and stables, or any location where carbon dioxide is stored, generated, or produced.

Important Technical Specifications

Sensor Type: NDIR (Nondispersive Infrared) Detectable Gas: Carbon dioxide (CO2) Power Supply: 11-28Vdc Max Power Consumption: 3.2W Measuring Range: 0...20,000 ppm Precision: ± 5% full scale, ± 10% readout Repeatability: ± 5% full scale, ± 10% readout Measurement Resolution: 20 ppm Microprocessor Resolution: 1024 points (10 bit) Digital Filter System: Kalman Filter Watchdog: Internal Warm-up Time: < 2m Stabilization Time: < 2m Response Time (T90): < 25s Average Sensor Life (in air): 255 weeks

4-20mA Output:

• Proportional Mode (default): 4mA = 0 ppm, 20mA = 20000 ppm
• Consumption Mode (for 1 or 2 thresholds): 0mA = no alarm, 10mA = 1st threshold alarm, 20mA = 2nd threshold alarm
• Output Reference Selection: By jumper selectable polarity
• Load Resistor: Up to 200Ω at 12Vdc power supply, 200Ω - 700Ω at 24Vdc power supply

Environmental Conditions:

• Operating Temperature: -20 ÷ 50 °C
• Storage Temperature: -20 ÷ 70 °C
• Relative Humidity (without condensing): Operation: 15 ÷ 90%RH, Storage: 45 ÷ 75%RH
• Operating Pressure: 80 ÷ 110 KPa
• Air Speed: ≤ 6 m/s

Visual Warnings: Red LED visible on the sensor body Dimensions (HxWxD): 164x100x82mm Weight: 0.8Kg

Optional Relay Card (UZR20.4):

• Relays: 4 SPDT relays (Pre-alarm, 1st alarm, 2nd alarm, Sensor fail)
• Contacts: NO or NC, jumper selectable
• Max Relay Capacity: 50mA at 24Vac/dc, 100mA at 12Vac/dc
• Relay Operating Mode: Direct (relay ON when event detected) or Reverse (relay ON when no event detected)

ATEX Markings:

• CE 1370 Ex II 2G Ex d IIC T6 Gb
• BVI 07 ATEX 0032 + Ext 02/14
• -20°C ≤ TA ≤ +50°C

Usage Features

Installation: The URD20SE is designed for installation in Zone 1 classified areas. Due to CO2 being about one and a half times denser than air, it tends to collect at floor level in enclosed, unventilated spaces. Therefore, the sensor should be installed approximately 30 cm above the floor. Specific installation guidelines include:

• Install where accidental gas leakages are possible.
• Maintain at least 1.5m distance from heat sources or vent holes.
• Avoid spaces with poor ventilation or where gas pockets may form.
• Ensure no hindrances to natural gas flow.
• Keep away from equipment that may leak gas during normal operations.
• Operate within a temperature range of -20°C to 50°C and relative humidity below 90% (non-condensing).
• Always disconnect power before mounting or dismantling.
• The device must be installed in compliance with EN 60079-14 Standard, using ATEX certified 1" NPT cable glands for cable entry (EN 60079-0 and EN 60079-1).
• Ground the sensor using its internal grounding system.

Cabling:

• Use at least 3-core cable with a minimum diameter of 0.75mm² for up to 100m, 1mm² for up to 200m, and 1.5mm² for up to 500m.
• Shielded cable is recommended where electromagnetic interference is a risk.
• For relay card usage, multi-core cable suitable for the number of connections should be used, ensuring the cable sheath fits the cable gland diameter.

Configuration: Default settings are provided in the "Technical Specifications." To change settings, power off the device, input new settings via the JP2 jumper circuit or S1 DIP switch, then power up. The 4-20mA output reference polarity can be selected via JP2 jumpers. The operating mode of the 4-20mA signal (proportional or threshold mode) is configured using the 5th selector of the S1 DIP switch. Threshold limit values for the optional relay card or the 4-20mA signal's threshold operating mode can be set using the first four selectors of the S1 DIP switch, with values expressed as a percentage of full scale (e.g., 3, 5, 10% or 10, 20, 40% default). Custom threshold values can be set using the TUS40 handheld terminal when the first four DIP switch selectors are in the OFF position.

Optional Relay Card Installation: The UZR20.4 relay card expands the control card with four SPDT relays for pre-alarm, 1st threshold, 2nd threshold, and sensor fail conditions, along with LED alerts. Installation involves inserting the connection slot into the CN3 connector, ensuring the flexible tab is towards the main terminal board, fitting the card snugly, and pulling the flexible tab towards the main terminal board. Electrical configuration requires selecting the relay operating mode (direct or reverse) and contact type (NC or NO) using JP1-JP4 jumpers and the 6th selector of the S1 DIP switch.

Maintenance Features

Sensors Lifetime: The average sensor lifetime is based on typical usage in a pollution-free environment. High concentrations of pollutants can shorten the sensing element's life. The detection system must be continuously supplied with energy throughout the sensors' lifetime; seasonal use is not recommended.

Checklist After Installation:

• Sensors are factory calibrated, but an operational check is recommended after installation.
• The detector enters a 2-minute warm-up phase, then switches to normal operating mode, but takes about 2 hours to reach top performance.
• During operation, a gas response check should be performed using the TUL40.. gas calibration kit, which includes 5000ppm CO2 and pure Nitrogen cylinders, a pressure valve, flow regulator, sensor body adapter, and hose.
• During the test, check the output current (7-9mA for 5000ppm CO2), the status LED on the sensor body, and, if present, the LEDs on the relay card.
• Use the Pure Nitrogen gas cylinder to check zero calibration.

Routine Maintenance: A functional sensor test should be carried out every three to six months, repeating the post-installation checks.

Corrective Maintenance: If abnormalities are found, the sensor should be returned to the supplier/installer for manufacturer repair. Recalibration may be necessary using the TUL40.. gas calibration kit and the TUS40 handheld terminal, connected via the CN4 communication interface. Instructions for recalibration are provided with the handheld terminal.

Decommissioning: To decommission, remove power, disconnect all wiring and conduits, and dismount the housing from any blocking systems.

Warranty: EsiWelma products have a 12-month warranty from the installation date, not exceeding 24 months from the manufacturing date. Proof of installation (data, stamp, and signature on the data sheet) is required for warranty claims. A copy of the warranty data sheet must be sent when returning the product under warranty.

Accessories:

• UZR20.4: Four-relay card
• TUL40..: Gas calibration Kit
• TUS40: Handheld terminal for service and maintenance
• CRG40: Gas collecting cone
• PAP40: Powerful jets protection

EsiWelma Sensigas URD20SE Specifications