PEMTECH PT395 Series User manual

PT395 Series
Stand Alone Gas Detector
Toxic, Oxygen Deficiency, & Combustible (HC)
Revision 5
September 2015
Operat
or’s
Manual
Pem-Tech, Inc.
Houston, Texas
U.S.A
www.pem-tech.com
Gas Detection Technology

PT395 Series Detector
2
Table of Contents
Notice and limited Warranty 3
Specifications 4
Overview 5
Table 1. List of target gases 6
Transmitter Board assembly 7
Connection Board assembly 7
Accessories 8
Installation 10
Transmitter Wiring 11
Wiring Diagrams
DC Power and 4-20mA Signal Output 13
Low and High Alarms Connections 14
Start Up 15
Normal Operation 16
Gas Reading Display 16
Signal Output 4-20mA 16
Alarm Conditions 17
Alarm & Sensor Fault 17
Calibration 18
Sensor calibration Procedure 18
Calibrating Oxygen Depletion Sensor 21
Figure 7. Calibration Apparatus Setup 23
Response check / Bump Test 24
Calibration errors and remedies 25
Calibration Flow Chart 26
Adjust Alarm Levels 27
Setting Alarm Set Point 27
Alarm Conditions 29
Resetting Alarms 30
MAINTENANCE
Routine maintenance 31
Sensor Inspection, sensitivity and replacement 32
Spare Parts 34
Sub-assemblies and calibration accessories

PT395 Series Detector
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IMPORTANT
Be sure to read and understand this instruction manual before installing,
operating or servicing the gas detection equipment.
WARNING
•Do not open the sensor enclosure with power applied unless it is verified that
no combustible gases or vapors are present. Calibration or maintenance
should not be performed if there is any indication of the presence of
combustible gas near the sensor.
•If anytime an intrusive sensor calibration procedure has to be performed then
de-classify the area before opening the sensor junction box.
•The sintered flame arrestor on the stainless steel sensor head is an integral
part of the complete sensor assembly. Do not operate the gas sensor with the
flame arrestor removed or damaged.
•The detector muse be earthed / grounded for the electrical safety. A safety
lug on the right side of the enclosure is provided for grounding.
CAUTION
•If needed the enclosure threads may be coated with silicone free grease.
Silicone based lubricants must never be used.
•Follow the wiring instruction for proper and safe operation under normal
conditions. Be sure that all wiring complies with NEC and all local ordinances.

PT395 Series Detector
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SPECIFICATIONS
Sensor Type:
Continuous diffusion / adsorption
Combustibles (HC): Infrared & Catalytic Bead
Carbon Dioxide: Infrared
Toxic and Oxygen: Electrochemical
Typical Measuring Ranges
See Table 1 for target gases and range
Repeatability
±2 % Full scale
Electrical Classification
Explosion Proof
ATEX: II 2 G EX d IIC T6 (Tamb = -34°C to +100°C)
CSA: Class I, Div 1 & 2, Groups B,C& D
C22.2 No 30-M1985 &
C22.2 No 142-M1987
Ingress Protection
NEMA 4X, IP66
Approvals
CSA , ATEX/IECEx
Typical Response Time &
Operating Temperature Range
See Table 1 for details
Operating Humidity
15% to 90% RH, non-condensing
Storage Temperature
-40°F to +167°F (-40°C to +75°C)
Mechanical Specifications
Height: 7.4inches (188 mm)
Width: 6.2 inches (159 mm)
Depth 4.9 inches (125 mm)
Display
3 Digit LED Display
Status Indicators
3 Digit LED display for gas concentration,
calibration mode and fault status.
3 LED for Alarm Status / indicators
Input Power
14-28 VDC. 24 VDC nominal
Power Consumption
Toxic: 65 mA @ 24 VDC typical
Infrared: 60 mA @ 24 VDC typical
Catalytic Bead: 240 mA @ 24 VDC typical
Alarm Relays
3 each Fully programmable for Low & High alarm levels and
sensor Fault. Also programmable as Latching or Non-
Latching
Relay Ratings
SPDT Form “C” type Relay contacts
1 Amps @ 250 VAC or 30 VDC
Analog Output
Linear 4-20mA ; 0 -100% Full Scale (300 Ohms max. load)
2.0 mA - Calibration mode
< 1.0 mA - Sensor malfunction
Cable Requirement
3 wire shielded cable for Power and Analog output
Terminal connectors 12 AWG Max
Input / Output Protection
Transient over voltage suppressor,
Reverse polarity protection
EMI/RFI Immunity
Cable Entry Hub
¾” NPT Female
Adapter available for ½” NPT / M20

PT395 Series Detector
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Overview
1. Model PT395 Sensor is a single point fixed detector and transmitter for the
detection of toxic and flammable gases in ambient air. Detector is designed
and built suitable to be used in hazardous area. The detector is approved for
use in Class I Division 1 & 2 classified areas (North America) or Zone 1 and 2
(International).
2. The transmitter features a display and three programmable relays for
controlling external devices like alarms, sirens, switches and solenoid
valves. The transmitter provides an industry standard 3-wire, 4-20mA
(source) output for connection to a gas detection system or a PLC.
Table I lists the target gases and the detection ranges. The unit displays the gas concentration
and transmits a linear 4-20mA analog output signal proportional to the gas concentration
displayed. The unit is also equipped with a forms “C” type alarm relay contacts.
The detector also features a non-intrusive calibration. Calibration is performed by activating an
internal magnetic switch. Calibration is an easy automated procedure that does not require
any manual adjustment to the unit. All calibration and alarm configuration data is retained in a
non-volatile memory.
Digital Display
Field Cable Entry (x2)
¾” NPT
One Entry with Ex Plug
Stainless Steel (316)
Sensor Head Assembly
Transmitter assembly
Mounting Holes (X2)
Earth Ground Lug
Figure 1. PT395 Series Detector
Alarm LED Indicators

Toxic Gases
Target Gas
Max Range
Sensor
Type
Res.
Calib Gas
Range
(user
Selectable)
Default
Calib Gas
Used
Response
time (T90)
seconds
Recovery
Time (T10)
seconds
XXX
Operating Temperature
Default alarm Levels /
Set Points
Min
Max
Alarm 1
Alarm 2
Ammonia
(NH3)
50 ppm
Electrochemical
Sensors
0.1 ppm
5-35 ppm
25 ppm
< 60
~ 90
-4°C / 24°F 50°C / 122°F 5 ppm 10 ppm
Carbon Monoxide
(CO)
100 ppm
1 ppm
20-50 ppm
50 ppm
< 25
~45
-20°C / -4°F 55°C / 131°F 20 ppm 50 ppm
Carbon Monoxide
(CO)
300 ppm
5 ppm
50-150 ppm
50 ppm
< 25
~45
-20°C / -4°F 55°C / 131°F 100 ppm 150 ppm
Chlorine
(CL2)
10 ppm
0.1 ppm
2-10 ppm
5 ppm
< 60
~50
-20°C / -4°F 55°C / 131°F 2 ppm 5 ppm
Hydrogen
1,000 ppm
10 ppm
100-500 ppm
500 ppm
< 35
~120
-20°C / -4°F 55°C / 131°F 200 ppm 500 ppm
Hydrogen Sulfide
(H2S)
100 ppm
1 ppm
20-50 ppm
50 ppm
< 35
~45
-40°C / -40°F 65°C / 149°F
(intermittent) 10 ppm 15 ppm
Hydrogen Sulfide
(H2S)
500 ppm
1 ppm
50-150 ppm
50 ppm
< 35
~45
-40°C / -40°F 65°C / 149°F
(intermittent) 50 ppm 100 ppm
Mercaptan
100 ppm
1 ppm
20-50 ppm
50 ppm
< 35
~ 45
-20°C / -4°F 55°C / 131°F 10 ppm 15 ppm
Nitrogen Dioxide
50 ppm
1 ppm
10-50 ppm
10 ppm
< 50
~ 75
-20°C / -4°F 55°C / 131°F 10 ppm 15 ppm
Nitric Oxide
(NO)
100 ppm
1 ppm
20-50 ppm
25 ppm
< 45
~ 50
-20°C / -4°F 55°C / 131°F 20 ppm 50 ppm
Oxygen
(O2)
25 %V/V
0.1 %
Calibrated in fresh air.
Purged with Pure Nitrogen
< 15
from 20.9% to 0
~ 40
-20°C / -4°F 55°C / 131°F
19.5%V/V
(falling)
Sulfur Dioxide
(SO2)
100 ppm
1 ppm
20-50 ppm
25 ppm
< 35
10 ppm SO2
~45
-20°C / -4°F 55°C / 131°F 5 ppm 10 ppm
Carbon Dioxide
(CO2)
5 %
Infrared
Sensors
0.1 %
2 – 5 %
2.5 ppm
< 35
~ 45
-40°C / -40°F 75°C / 167°F 2 % 3.5 %
Carbon Dioxide
(CO2)
100%
1 %
10 – 100 %
50 ppm
< 35
~ 45
-40°C / -40°F 75°C / 167°F 20 % 50 %
Combustible Hydrocarbons
Target Gas
Max Range
Sensor Type
Res.
Calib Gas
Used
Response Time
(T90) seconds
Recovery Time
(T10) seconds
Accuracy
%
Operating Temperature
Default alarm Levels /
Set Points
Min
Max
Alarm 1
Alarm 2
Flammable
(Hydrocarbons)
100 % LEL
(5% Methane in
Air)
Catalytic
Bead 1 % 50 % LEL < 25 ~ 40 ±2 -40°C / -40°F 75°C / 167°F 20 % 40 %
Hydrocarbons
(Methane /
Propane)
100 % LEL Infrared 1 % 50 % LEL (methane or
propane) < 25 ~ 40 ±2 -40°C / -40°F 75°C / 167°F 20 % 40 %
Table 1. Reference Table for Target Gas Range and default parameters
Rev 2: 1/5/16

Transmitter Board
The transmitter board assembly consists of the signal conditioning circuit,
microprocessor, LED display and 4-20 mA output circuit. The transmitter board
assembly is connected to the connection board via ribbon cable and secured
onto the stand-off via two thumb screws. To remove the transmitter board
simply move the thumb screws counter-clockwise and slowly pull the transmitter
board away. Unplug the ribbon cable to completely remove the transmitter
board from sensor unit.
Note: Do not use force to tighten the thumb screws when installing the
transmitter board back on the connection / termination board.
Connection Board
The termination or connection board consists of relays and DC-DC power
converters for the transmitter board and the sensor. The power converters are
protected against reverse polarity.
A 3 pin terminal is provided for user interface to the monitoring device for power
input and 4-20ma output. Three (3) Pin terminal blocks are also used for alarm
connections. Each pin on alarm terminal block is labeled as C (common), NC
(normally closed) and NO (normally open). See Figure 3.
The 4 pin terminal at the bottom of the board is labeled SENSOR. Wires from the
sensor head assembly are connected to this terminal.
Each terminal contact is labeled as R(ed), G(reen), W(hite), B(lack). the toxic
sensors are 4 wires while Hydrocarbons LEL (Catalytic bead) and all infrared
sensors are 3 wires.
See figure 2 for drawing of Transmitter board and connection board assembly.

PT395 Series Detector
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Accessories
Range of accessories is available for the use of detector in various applications.
Rain / Dust guard: To protect the sensor head assembly against the
accumulation of dust / sand on the sintered disk of the head assembly. Also to
protect against water splashes.
Duct Mount Kit: This is an optional kit designed to monitor the gas vapors in
Heating, ventilation and air conditioning duct (HVAC).
Figure 2. PT395 Series Transmitter and connection board assembly
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PT395 Series Detector
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Flow Thru Adapter. A machined aluminum assembly with either 1/8” Hose barb
fittings or ¼” Compression fittings. This adapter is designed to use in application for
continuous flow of gas through the sensor head assembly.
Calibration Adapter with Tubing: Also a part of calibration accessories. Used
along with the flow regulator to flow the calibration gas to the sensor. Attached is 6
feet ¼” nylon tubing.
Magnetic Wand: A tool used to initiate the internal magnet sensitive switches for
alarm configuration and to initiate sensor calibration.
Pipe Mount Assembly: Includes hex bolts and stainless steel bracket to mount
the sensor to up to a 2” pipe.

PT395 Series Detector
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Installation
Refer to figure 3 for Detector explosion proof enclosure for mounting and conduit
connection.
The unit has 2 integral mounting holes. The unit can be mountd directly to a surfce
or to a horizontal or vertical pipe structure. An optional pipe mount bracket can be
used to mount the unit to a pipe up to 2” in diameter or cross section. Two (2)
Cable entries are provided on each side of the enclosure. Either side can be used for
the cable entry. The other side must be plugged with the one supplied with the
unit. An approved plug for hazardous location must always be used.
5.50"
7.4"
4.9"
(125mm) (139.7mm)
(188mm)
Ø 0.3" (7.6 mm)
2 Places
3
4" NPT Female
Both Sides
Cable Entry
Figure
3. Overall Dimensions