Acutec 35 Gas Detection System

Summary

Product identification

The Acutec™ 35 is a self-testing gas detection system designed for ambient air monitoring. It is available in a compact, modular design with sensors for chlorine (Cl₂), ammonia (NH₃), or sulfur dioxide (SO₂).

Key Benefits

• Gas detection for Chlorine, Ammonia or Sulfur Dioxide
• Simple and neat installation of module components
• Easy access to control panel via a hinged cover on the NEMA 4X enclosure
• Audible horn to provide local warning
• Choice of Detector or Monitor version
• Sunlight readable 4 digit LED on the monitor
• Single or multipoint gas detection systems
• Automatic integral gas generator

Installation

The modular system allows for single or multipoint configurations. Each detection point requires one sensor/transmitter and one receiver module. The sensor/transmitter is installed in the area to be monitored, and the receiver module can be located up to 1000 feet away. Receiver modules and a power supply module are housed in NEMA 4X enclosures.

Enclosure

• NEMA 4X Polystyrene enclosures with knockouts for 1/2” (12.7 mm) FNPT conduit hubs.
• Provided with four conduit hubs for single-point enclosures and seven for dual-point enclosures.
• Fitted with a hinged polycarbonate window.
• Includes a piezoelectric horn for audible local warning.

Receiver Module

Two versions are available:

• Detector: Signals gas presence, includes two gas alarm set points, three configurable alarm relays, and a separate sensor alarm relay.
• Monitor: Includes all Detector features plus a 4-digit LED display of gas concentrations (PPM) and an isolated 4-20mA output.

Both versions are switch-programmable for full-scale range and feature front panel switches for alarm acknowledgement, reset, relay inhibition, Auto-Test activation, and LED indicator testing.

Power Supply Module

• Accepts AC input between 85-255 VAC, 50/60 Hz.
• Provides a regulated 12 VDC output for receiver modules.
• Supports up to two receiver modules.
• Includes a power failure alarm relay.
• Powers an integral audible alarm and charges the optional battery back-up.

Sensor/Transmitter

• Combines an electrochemical gas sensor with a transmitter, housed in a NEMA 4X enclosure.
• Digitally converted measurements are sent to the receiver module up to 1000 feet away via two-wire cable.
• Optional auto-test facility with an integral gas generator performs daily sensor tests and alarms on failure or reduced sensitivity.

Optional Battery Back-Up System

• Consists of a sealed lead-acid battery in its own enclosure.
• Maintains receiver functions for a minimum of 12 hours (single point) or 6 hours (dual point) in the event of power failure.
• Features automatic, continuous battery charging via the power supply module.

Technical Data

Gases Detected

• Chlorine (Cl₂)
• Sulfur Dioxide (SO₂)
• Ammonia (NH₃)

Gas Ranges

• Cl₂: Std. 0-10 ppm, Min. 0-5 ppm, Max. 0-50 ppm
• SO₂: Std. 0-20 ppm, Min. 0-10 ppm, Max. 0-100 ppm
• NH₃: Std. 0-100 ppm, Min. 0-50 ppm, Max. 0-500 ppm

Power Requirements

• 85-255 VAC, 50/60 Hz, 1 Amp - Self-regulating

Ambient Conditions

• Temperature: 0° to 105°F (-18° to 40°C) continuous; -10° to 120°F (-23° to 49°C) intermittent
• Humidity: 0-99% non-condensing

Gas Alarm Setpoints

• 2 independent setpoints
• Warning Level: adjustable from 5% to 100% of range
• Alarm Level: adjustable from 5% to 100% of range

Alarm Indicators

• High intensity LED bars
• Warning indicator: non-latching
• Alarm indicator: latching

Alarm Relays

• Three assignable alarm relays (SPDT) for alarm setpoints.
• 10A at 120 VAC, 5A at 250 VAC, resistive.
• Configurable for normal/fail-safe, latching/non-latching, and fast/slow operation.

Sensor Alarm

• Indicates loss of sensor/transmitter input or failure of optional sensor Auto-Test.
• Includes a front panel LED indicator and a relay (10A at 120 VAC, 5A at 250 VAC, resistive SPDT, factory set to fail-safe).

Monitor Features

• Concentration Display: 4-digit LED, sunlight readable.
• Concentration Output Signal: Isolated 4-20 mA DC, 1000 ohms maximum load.

Power Supply Output

• Regulated 13.7 VDC, 1A supplied to 1 or 2 receivers. Also used for battery charging, audible back-up, and integral alarm horn power.

Audible Alarm Horn

• Weatherproof 12 VDC piezoelectric horn with 85-dB output.

Power Failure Alarm Relay

• Indicates loss of AC input power.
• 1 relay (10A at 120 VAC, 5A at 250 VAC, resistive SPDT).

Gas Sensor

• Type: Electrochemical gas diffusion
• Connection Distance: Up to 1000 feet (300 m) to receiver via two-wire cable.
  • Dual point units include 50 ft. (15 m) of cable.
  • Single point units include 25 ft. (8 m) of cable.
• Operating Life: 2 years
• Storage Life: 5 years

Optional Battery Back-Up

• Battery Type: 12 VDC, 4 Amp HR sealed lead-acid
• Battery Capacity:
  • Single point unit: min. 12 hrs. (avg. 24 hrs.)
  • Dual point unit: min. 6 hrs. (avg. 12 hrs.)
• Charge Control: Current limited to 0.75A max.
• Charge Time: Typically 10 hours from fully discharged.
• Low Voltage Cutoff: Relay disconnect at 10 VDC.
• Battery Life: Min. 3 yrs. in operation.

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Disclaimer: This extraction may miss figures, footnotes, or revisions. Contractual data must match the OEM PDF revision used on the project.

Official datasheet (PDF)

Lenntech datasheet mirror