Hansen HLM2 - User Manual

To Next Page

Specifications, Applications,

Service Instructions & Parts

GAS DETECTION

SENSORS, MONITORS

& ALERT SYSTEMS

Bulletin A100b

JAN 2009

For Refrigerants and

other Common Gases

Standard Gas Sensor

INTRODUCTION

Hansen Technologies offers a complete line of industrial

quality Gas Detection Sensors, Monitors and Alert

Systems for refrigerants and other common gases.

These state-of-the-art gas detection products utilize a

range of sensing technologies to suit a given application.

Available in several configurations to meet various

application requirements with optimum accuracy and

reliability.

APPLICATIONS

Hansen Gas Sensors are suitable for use in industrial

refrigeration engine rooms, cold storage rooms,

processing rooms, truck docks, and for relief valve vent

lines. They are also suitable for use in supermarkets,

and large institutional and commercial buildings.

Typical gas detection applications include Ammonia,

Carbon Dioxide (CO2), Hydrocarbons, HFCs, HCFCs

and CFCs.

ADVANTAGES

Hansen uses a wide variety of sensing technologies

including electrochemical, semiconductor and infrared

sensors to selectively detect most gases. These sensors

continuously determine the level of gas present in the

surrounding environment. The analog outputs (4-20mA

or 0-10V DC) can interface with nearly any existing

monitor, computer or PLC controller.

The sensing elements (except Basic and Extreme Gas

Sensors) are mounted externally on the enclosure. This

helps to provide quick response to potential leaks,

particularly in still air. Electronics are sealed in a NEMA4

enclosure (except Basic Gas Sensor) which protects them

from moisture, dust and the surrounding gases, which in

the case of ammonia can shorten the life of electronics.

The sensing elements are easily replaced.

Gas Sensors have built-in visual and audible alarms.

An auxiliary one amp SPDT relay output is standard.

Testing and recalibration procedures are simple.

KEY FEATURES–GAS SENSORS

Accurate, fast responding•

Linear 4-20mA or 0-10V DC output•

Audible alarm•

Power indicator•

SPDT alarm relay (Fail Safe Operation)•

24V AC/DC low voltage power •

Shipped factory calibrated and tested•

CE approved•

KEY FEATURES–MONITORS

Visual alarm•

Audible alarm•

Power indicator•

Low level alarm relay•

High level alarm relay•

Fault relay (HLM6 only)•

Economical•

CE approved•

KEY FEATURES−GAS ALERT SYSTEM

Provides local display and alarm based on •

measured target gas level via gas sensor

Visual alarm, Amber LED light•

Audible alarm (mutable)•

Power indicator, Green•

Numeric PPM reading•

Bright LED Display•

Shipped factory calibrated and tested•

Main Page

Need help?

Do you have a question about the Hansen HLM2 and is the answer not in the manual?

The Hansen Gas Detection Sensors, Monitors & Alert Systems are a comprehensive line of industrial-quality gas detection products designed for refrigerants and other common gases. These systems utilize state-of-the-art sensing technologies to meet various application requirements with optimum accuracy and reliability.

Function Description

The Hansen Gas Detection systems continuously determine the level of gas present in the surrounding environment. They provide local displays and alarms, and can also interface with external monitoring systems.

Gas Sensors: These units are designed to detect specific gases and output an analog signal (4-20mA or 0-10V DC) proportional to the gas concentration. They feature built-in visual and audible alarms, as well as an auxiliary one-amp SPDT relay output for fail-safe operation.

Monitors (HLM2, HLM6): These devices provide visual and audible alarms, power indicators, and alarm relay outputs. The HLM2 is a two-channel monitor with an internal audible alarm, while the HLM6 is a six-channel monitor with an external audible alarm and an additional fault relay output. They are designed to interface with gas sensors and provide centralized monitoring.

Gas Alert System: This system provides a local display and alarm based on the measured target gas level from a gas sensor. It features a visual amber LED light, a mutable audible alarm, a green power indicator, and a bright LED display showing numeric PPM readings. It can function as a standalone unit or as part of a larger monitoring system.

Important Technical Specifications

Gas Sensors:

Output: Linear 4-20mA or 0-10V DC.
Power: 24V AC/DC low voltage.
Alarm: Audible alarm, SPDT alarm relay (fail-safe operation).
Operating Temperature Range:
- Basic/Standard: 0°F to 105°F (-17°C to 40°C).
- Harsh/Vent Line/Explosion Proof: -40°F to 105°F (-40°C to 40°C).
- Extreme: -60°F to 105°F (-51°C to 40°C).
Humidity Range (Non-Condensing): 0-95% (0-100% for Extreme).
Max. Loop Resistance: 1000 Ohms.
Enclosures:
- Basic: NEMA1 (IP41) ABS.
- Standard/Harsh/Vent Line: NEMA4 (IP65) ABS.
- Extreme: NEMA4X (IP65) Stainless Steel.
- Explosion Proof: NEMA7 Aluminum (Class I, Div II, Group C and D).
CE Approved.

Monitors (HLM2, HLM6):

Operating Temperature Range: 32°F (0°C) to 125°F (50°C).
Power Required: 120V AC (230V AC available).
Output:
- HLM2: 2 SPDT dry contact relays (alarms) - 10 amp @ 230V AC.
- HLM6: 2 SPDT dry contact relays (alarms) - 10 amp @ 230V AC, 1 SPDT dry contact relay (fault output) - 10 amp @ 230V AC.
Audible Alarm:
- HLM2: Internal 80 dB.
- HLM6: External 110 dB/12V DC.
CE Approved.

Gas Alert System:

Operating Temperature Range: -10°F (-23°C) to 125°F (50°C).
Humidity Range (Non-Condensing): 0-95%.
Voltage Requirements: 24V AC/DC, 50/60 Hz.
Display: LED, Red (numeric PPM reading, bright LED display).
Audible Alarm Sound Pressure: 97dB at 2 feet (mutable to 60dB).
Visual Alarm: Amber LED light (38 lumens).
Enclosure: Watertight, NEMA4X (IP65).

Usage Features

Gas Sensor Location:

Sensors should be located in accessible areas, away from moving equipment, thermal extremes, and strong drafts.
For heavy gases (vapor density > 1), sensors should be near ground level.
For light gases (e.g., ammonia), sensors should be mounted 12"-24" from the ceiling.
"Point" detection places sensors near likely leak sources, while "Perimeter" detection surrounds the area.
In ventilated rooms, sensors should be placed downstream of potential leak points.
For relief valve vent lines, the sensor element should be installed near the outlet of the vent line, with electronics mounted at a convenient height for servicing.

Wiring:

Gas Sensors: Use three-wire (VDC supply) or four-wire (VAC supply) twisted pair shielded cable. Signal wires (low voltage) should not be in common conduit with power wiring over 48 volts or near VFD equipment.
Monitors: Install on a wall or electrical panel. Connect specified AC power (120V or 230V) with minimum 18 gauge wire.
Gas Alert System: Can be mounted to any solid flat surface (screw or DIN-rail). Lower cover must be removed for wiring access.

Alarm Settings:

Gas Sensors: The trip point for the relay and alarm horn is set by adjustment screw A, with a default factory setting of 50% of the range. Time delays for alarms (1, 5, or 10 minutes) can be selected via jumpers JP5 and JP6. The alarm horn can be disabled via jumper JP2.
Monitors: Low level alarms reset automatically. High level alarms require a manual reset. The audible alarm can be disabled via a key switch.

Maintenance Features

Calibration:

Frequency: Recalibration should be performed at least once a year, or more frequently if exposed to high gas concentrations. Insurance companies and local agencies may require more frequent testing.
Procedure:
1. Ensure system safety and power up for at least 24 hours for stabilization.
2. Verify green LED is on and red LED is off. Disable internal horn (JP2 jumper).
3. Zero Calibration: Adjust the zero potentiometer (Z) until the voltmeter reads between zero volts and +/- 0.090VDC in a target gas-free atmosphere.
4. Span Calibration: Place the boot over the sensor element, apply calibration gas, and adjust the span potentiometer (S) until the output voltage reads between 4.95 to 5.00 volts DC.
5. Do not re-adjust zero or span calibration until another 24 hours of powered operation.
Zero Offset (Electrochemical Sensors): A maximum zero offset of 2% may occur if calibrated at one temperature and moved to another. This can be adjusted if unacceptable.
Calibration Gas: Hansen provides NIST-traceable calibration gas cylinders for various refrigerants and PPM ranges. Store in a cool area (65°F/75°F).

Sensing Element Replacement:

Typical Life: Electrochemical (2-3 years), Semiconductor (7-8 years), Infrared (8-10 years). Exposure to high gas levels or extreme humidity can shorten life.
Basic Sensors: Three-pin (Ammonia) or six-pin (Halocarbon) plug-in element. Disconnect power, open enclosure, and lift element off the circuit board. Infrared elements (CO2) are not replaceable.
Standard, Harsh, Explosion Proof Sensors: Externally mounted. Disconnect power, open enclosure, disconnect cable, and unscrew element from enclosure.
Extreme Sensors: Internally mounted. Disconnect power, remove nut and gasket, open enclosure, and disconnect cable.
After replacement, connect power, allow 24 hours for stabilization, recalibrate, and install the cover.

Troubleshooting:

No lights on monitor: Check power, circuit breaker/fuse, or unit warming up.
Red light on, no alarm: Check horn deactivation, wiring/sensor fault, calibration, or missing resistor in unused sensor channel (HLM6).
Sensor green light off: Check wiring, power supply, HLM6 fuse, or sensor damage.
Sensor output 0.5mA (4-20mA) or 0V/.5V (voltage output): Sensing element disconnected or failed. Check wiring and installation.

Hansen HLM2 Specifications

General

Brand	Hansen
Model	HLM2
Category	Accessories
Language	English