Manning Systems VL Operating Manual

VL-F7-N4-LPA-MK

Vent Line Sensor
for Ammonia and
Other Refrigerants

Instruction and
Installation Manual

MOUNT ENCLOSURE THIS END UP.

DO NOT BLOCK PERFORATED VENT HOLES.

Linear 4/20 mA Output

PRE-AMP

®

405 Barclay Boulevard
Lincolnshire, Illinois 60069
Tel: [phone]
Toll free: [phone]
Fax: [phone]
[e-mail]

Manning VL-F7-LPA Gas Sensor 18394 VLF7LPA 02/2005 REVF Copyright © 2005 Manning Systems, Inc. All Rights Reserved. 1

18394 VLF7LPA 07/2016 REV H

Contents Serial number:

Section Title Page

1 Sensor Description 3

2 Installation 5

3 Operation 8

4 Limited Warranty 10

Special Caution

Always assume that a relief valve can release at any moment. Always employ a “buddy” system,
having help with you and watching what you are doing at all times. Always use safety goggles
or a safety face shield, and always use gloves and have additional protective equipment easily
available, including eye flushing equipment and a breathing apparatus.

Personnel should be well trained and protected against falling if a sudden refrigerant leak
startles the service person. Make sure there is always an escape route in case of a refrigerant
release.

Introduction

This manual has been prepared to help in the use and installation of the Manning Systems
VL-F7-LPA Vent Line Sensor. This manual will convey the operating details of the sensor,
ensure proper installation, and demonstrate start-up and routine maintenance procedures.

This manual must be carefully followed by all individuals who have or will have the
responsibility for using or servicing the sensor.

with respect to this equipment will be voided if the equipment is not used and serviced in
accordance with the instructions in this manual. If in doubt about a procedure, please contact
Manning Systems, Inc. before proceeding.

Warranties made by Manning Systems, Inc.

Manning VL-F7-LPA Gas Sensor 18394 VLF7LPA 02/2005 REVF Copyright © 2005 Manning Systems, Inc. All Rights Reserved. 2

1 Sensor Description

The Manning Systems VL-F7-LPA Vent Line Sensor has
a solid-state sensor imbedded in a 2" forged steel bull
plug. A NEMA 4, 16 gauge steel box is fastened to the
bull plug and houses a terminal strip. This is then
wired to the current pre-amp which transmits a linear
4/20 mA signal to the readout equipment.

The standard trip points are normally in the 5,000 ppm
to 10,000 ppm range. Manning Systems highly
recommends that trip points be in this range due to
the fact that minute amounts of a refrigerant released
in the very small volume of a relief header will cause
very high gas concentrations, normally in the percent
range. Trying to have lower setpoints almost always
results in false trips.

The solid-state sensor used in this design must be
considered “broad-spectrum,” i.e., it will detect many
gases. Normally this is not a problem due to the higher
setpoints commonly used.

The VL-F7-LPA Vent Line Sensor should only be used
in non-hazardous locations. Explosion-proof designs
are not available at this time.

Figure 1: Dimensions of the Vent Line Sensor
and Pre-Amp

4 1/2"

2 3/8"

2" N.P.T.
pipe plug

7/8" diameter hole for 1/2"
conduit electrical connection

2"

5/16" diameter

3 1/8"

The sensors normally exhibit long life (five to eight
years) unless exposed to very high gas concentrations
for long periods or immersed in liquid refrigerant.

Proper location in mounting the vent line sensor is the
key to long and trouble-free life.

Carefully review the

mounting instruction portion of this manual.

MOUNT ENCLOSURE THIS END UP.

DO NOT BLOCK PERFORATED VENT HOLES.

PRE-AMP

6 3/4"

®

Manning VL-F7-LPA Gas Sensor 18394 VLF7LPA 02/2005 REVF Copyright © 2005 Manning Systems, Inc. All Rights Reserved. 3