LPT-A-VLT Ammonia Vent Line Transmitter

For continuous monitoring of Ammonia levels in the vent line of refrigeration systems

Mount indoors on the ammonia vent relief stack above the pressure relief valve or mounted outside on the relief 
header above the roofline to help detect equipment failure

Key Features

• Single channel, internal catalytic Ammonia sensor
• Linear 4 - 20 mA analog or 0 - 10 volt output signal
• LCD display
• One 2A SPDT dry contact relay
• Internal audible alarm
• 3-wire VDC or 4-wire VAC power
• 24 volt DC or AC power (nominal)
• IP54 rated, water / dust tight, corrosion resistant enclosure with splash guard installed

The LPT-A-VLT Ammonia Vent Line Transmitter is designed for continuous monitoring of ammonia levels in the 
vent line of refrigeration systems.  More specifically, it is designed for the detection of equipment failure in ammonia 
plant vent stack applications. Using the 3/4” cast steel coupler, it can be mounted indoors on the ammonia vent 
relief stack above the pressure relief valve or mounted outside on the relief header above the roofline. It can be 
configured to alarm at user specified concentration levels and send an analog signal to the controller or PLC to 
activate the emergency ventilation system or shut down the equipment depending on the level of alarm.

It offers 3-wire VDC or 4-wire VAC power, jumper selectable 4 - 20 mA or 0 - 10 VDC analog output, a standard dry 
contact relay (2 amps @ 30 volts SPDT), automatic thermal resetting fuse, temperature compensation, back lit LCD 
display and audible alarm, all in a RoHS compliant package. Comes standard with a water / dust tight, corrosion 
resistant ABS / polycarbonate enclosure with a hinged, secured door. Calibration and other maintenance procedures 
are simple and easily performed in the field.

NOTE: This device is not designed to monitor ammonia in applications requiring human health safety levels 
detection. A large release of a high concentration of ammonia may burn out the sensor, requiring replacement of 
the sensor.

Target Gas

Gas Sensor					                Ammonia (NH3), measurement range 0 - 3.00% volume

Sensor

Type						                Catalytic NH3

Response Time T90					< 30 seconds

Mechanical

Enclosure						        ABS / Polycarbonate, corrosion resistant 
						                Copper coated interior to reduce RF interference 
						                IP54 rated

Weight						        825 g / 29 oz

Size						                127 x 127 x 61 mm / 5.0 x 5.0 x 2.4 inches

Coupler						        19.5 mm / 3/4 inch NPT, cast steel

Sensor Assembly length (including coupler)		98.5 mm / 3.875 inches

User Interface

Display						        Graphic LCD, grey border 
						                Magnetic switches to initiate calibration without opening the 
                                                                enclosure

Input/Output

Output						        Linear 4 - 20 mA analog 
						                Maximum 216 ohm load (wiring plus termination resistor) @ 12 VDC 
						                Maximum 316 ohm load (wiring plus termination resistor) @ 12 VAC 
						                Voltage 0 - 10 volt 
						                Minimum 1k ohm load

Relay						                1 SPDT dry contact, rated 30 Volts, 2 Amps max

Audible Alarm					        Standard internal buzzer

Electrical

Power Requirement					3-wire mode: 16-30 VDC, 3 W, Class 2 
						                4-wire mode: 12-27 VAC, 50-60 Hz, 3 VA, Class 2

Current Draw					        125 mA @ 24VDC (max)

Wiring						        VDC (or ground referenced AC): 3-conductor 16 AWG stranded, 
                                                                shielded 
						                VAC: 4-conductor 16 AWG stranded, shielded

Fuses						                Thermal, resetting

Environmental

Operating Temperature				        -20°C to 40°C (-4°F to 104°F)

Operating Humidity					0 - 80% RH non-condensing

Certifications

Conforms to					                CSA-C22.2 No. 205-12, UL508 (Edition 17):2007 
						                EMC Directive 2004/108/EC, EN 50270:2006, Type 1, EN61010 
						                FCC. This device complies with part 15 of the FCC Rules. Operation 
                                                                is subject to the following two conditions: (1) This device may not 
                                                                cause harmful interference, and (2) this device must accept any 
                                                                interference received, including interference that may cause 
                                                                undesired operation. 
						                RoHS compliant circuit boards