PEMTECH PT295 Series Manuel utilisateur
Table of Contents
Notice and limited Warranty 3
Service Policy 4
Specifications 6
Overview 7
Target gases and Detection Ranges 8
Transmitter Board assembly 9
Connection Board assembly 10
Wiring Diagram
DC Power and 4-20mA Signal Output 11
Low and High Alarms 12
Installation 13
Start Up 15
Normal Operation 16
Gas Reading Display 16
Signal Output 4-20mA 16
Alarm Conditions 17
Low & High Alarm, Fault 17
Resetting Alarms 18
Calibration 19
Sensor calibration 19
Recommended Calibration Gases 22
Calibration errors and remedies 25
Calibration Flow Chart 26
Adjust alarm set points 27
Setting Low & High Alarm Levels 27
MAINTENANCE
Factors affecting sensor accuracy 28
Routine maintenance 28
Sensor Inspection 28
Sensor Sensitivity 28
Sensor Replacement 29
Spare Parts 30
Part Numbers for transmitter boards 30
And sensor head assembly
Part Numbers for recommended calibration gases 31
PT295 Series Toxic Sensor Rev 5.1
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NOTICE
PEM-TECH INCORPORATED SHALL NOT BE LIABLE FOR TECHNICAL OR
EDITORIAL ERRORS OR OMISSIONS MADE HEREIN; NOR FOR INCIDENTAL
OR CONSEQUENTIAL DAMAGES RESULTING FROM THE FURNISHING,
PERFORMANCE, OR USE OF THIS MATERIAL.
LIMITED WARRANTY
PEM-TECH Incorporated warrants all equipment manufactured by it to be free from
defects in workmanship and material, provided that such equipment was properly
selected for the service intended, properly installed, and not misused. Equipment
received by Pem-Tech for warranty repair or replacement will be return-shipped at
the lowest transportation cost.
The warranty provided by Pem-Tech does not cover defects which result from acts
beyond the control of PEM-TECH including, but not limited to: damage by accident,
negligence, tampering, or failure to operate in accordance with the procedures
outlined in the Operations Manual. PEM-TECH’s liability under no circumstances
will exceed replacement of the unit claimed to be defective.
The warranties specified herein are in lieu of any and all other warranties, express or
implied. In no event, whether as a result of breach of warranty or alleged
negligence, shall PEM-TECH be liable for special or consequential damages,
including, but not limited to, loss of profits or revenue; loss of equipment or any
associated equipment; cost of capital; cost of substitute equipment, facilities or
services; down time costs; or claims of customers of the purchaser for such damages.
Please call factory for RMA (return merchandise authorization) number before sending any
equipment for repair or replacement.
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SERVICE POLICY
Pem-Tech has service facility at the factory. For all the repairs contact at our toll free
number 1-800-379-3894 or visit our website www.pem-tech.com
For all repairs call us for a Return Material Authorization number (RMA). Inform us
briefly the nature of the problem and obtain shipping address. Properly pack the
equipment before shipping. Also include your complete shipping address and
contact name and phone number.
For non-warranty repairs you must provide the limit to repair costs. State if a quote
for repair cost is required before you can authorize the repair cost. For this an
additional charge may be applicable.
NOTE:
1. For all the repairs under warranty, serial number must be legible on the items
being repaired.
2. Shipping point is FOB Houston.
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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.
CAUTION
•If needed the sensor threads should be coated with silicone free grease. The
junction box cover threads should also be lubricated .
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.
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SPECIFICATIONS
SENSOR TYPE Electrochemical Cell
WEIGHT 4 Lbs.
RANGE See Table I
TEMPERATURE RANGE: -4 °F to 122 °F ( -20 °C to 50 °C )
Or 20 °C to 65 °C intermittent
HUMIDITY: 0 to 95% RH, non-condensing
ACCURACY: ±5 % of full scale
REPEATABILITY: ±5 % of gas applied
RESPONSE TIME: With full scale gas applied:
90% full scale in < 30 seconds
CLASSIFICATION: CSA class I, Div. 1 & 2 Groups B,C, & D
CE0081 II 2 G Ex d IIC T6
Suitable for use in hazardous locations
POWER INPUT: 14 - 30 VDC ( 24VDC Nominal)
POWER CONSUMPTION: < 1.5 Watts
ANALOG OUTPUT 4-20mA DC linear.
Maximum of 300 Ohms loop resistance
DISPLAY 3 Digit LED display.
ALARM RELAY Form “C” type Alarm Relay contacts
Relay rating: 2 amps @ 30VDC or 125 VAC
Fully programmable,
Normally open or Normally closed,
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Overview
Model PT295 is a single point fixed sensor for the detection of toxic gases in ambient
air. Table I lists the target gases and the detection ranges. PT295 displays the gas
concentration and transmits a linear 4-20mA analog output signal that is
proportional to the gas concentration displayed. The unit is also equipped with a
form “C” type alarm relay contacts.
The sensor also features a non-intrusive calibration. Calibration is performed by
activating an internal magnetic switch. All calibration and alarm configuration data
is maintained in a non-volatile memory
Sensor transmitter board and connection board are enclosed in an explosion proof
junction box (rated Class I, Div 1 & 2). The unit consists of three assemblies, the
transmitter and display board, the connection board, and the stainless steel sensor
head assembly. Each of these assemblies can be purchased separately.
Figure 1. Model PT295 Sensor
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Target gases and detection Ranges
Table I
Target Gas Detection
Range
Hydrogen Sulfide (H
2
S)
100 ppm
Carbon Monoxide (CO)
100 ppm
Or
1000 ppm
Sulfur Dioxide (SO
2
)
50 ppm
Ammonia (NH
3
)
50 ppm
Nitrogen Dioxide (NO
2
)
20 ppm
Nitric Oxide (NO)
100 ppm
Hydrogen Chloride (HCL)
100 ppm
Chlorine (CL
2
)
10 ppm
Oxygen deficiency (O2)
25 %
Hydrogen (H
2)
200 ppm
Methyl Mercaptan (CH
3
SH)
)
100 ppm
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Transmitter Board
The transmitter board assembly consists of the signal conditioning circuit,
microprocessor, digital 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.
Figure 2. Model PT295 Transmitter and connection board assembly
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Connection Board
The termination or connection board consists of alarm relay 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. A three (3) Pin terminal block is 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. Four (4) wires
from the sensor head assembly are connected to this terminal.
These wires are connected as follows:
R Red wire (Sensor Positive 5 VDC Supply)
G Green Wire (Sensor Ground)
W White Wire (Sensor signal out) and
B Black wire (Sensor -5VDC Supply)
Note:
Oxygen sensor head has only 2 wires (Black and white). Thus only these 2 wire
connections are required
For proper operation these wires must be connected as noted above.
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Table des matières
Autres manuels PEMTECH Accessoires
