Detcon Model 971-041170-00K
detcon inc.
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etcon inc.
H
OUST ON , T EX AS
SAMPLE DRAW
GAS DETECTION SYSTEM
SET
FLOW
CAL
IN
C
L
O
S
E
O
P
E
N
SAMPLE
VALVE
C
L
O
S
E
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P
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VENT
ON/OFF
FLOW FAULT
POWER
Gas Detection System For Highly Corrosive Gases
Operator's Instruction Manual
Deceember 4, 2009 Document #3525 Rev 0.0
Detcon Model 971-041170-00K gas detection system consists of 2 major assemblies:
1. The NEMA 4 fiberglass sample draw enclosure.
2. The remote mount gas sensor assembly.
The NEMA 4 fiberglass sample draw enclosure is detailed in section 1 of this manual. The remote mount gas sensor
assembly is detailed in the attached sensor manual.
1.0 DESCRIPTION
10.5"
11.5"
21.75"
19.5"
20.5"
23.5"
Mounting Holes
.312" Dia.
1/8" or 1/4" Teflon Tubing
Max Distance 150 ft.
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detcon inc.
H
OUSTO N, T E XA S
SAMPLE DRAW
GAS DETECTION SYSTEM
SET
FLOW
CAL
IN
C
L
O
S
E
O
P
E
N
SAMPLE
VALVE
C
L
O
S
E
O
P
E
N
VENT
ON/OFF
FLOW FAULT
POWER
he Detcon Model 971-041170-00K is a 117VAC powered gas detection system that provides a remote gas sample to an
T
independent sensor assembly. This sample system is unique in that all gas flow path materials upstream of the sensor are
teflon so that gas sample adsorption is minimized for highly reactive gases. There is a highly reactive scrubber inserted
after the sensor to remove these corrosive components so that they do not effect the downstream sample flow components. The sensor assembly, discussed in a separate sensor manual, is specified at time of order as to gas and range of
detection. The NEMA 4X rating is by definition raintight and therefore is suitable for outdoor location in electrically
non-hazardous environments.
The enclosure houses a 24 VDC power supply, flow pump, and flow fault detection circuit. A PCB motherboard
provides lugless field wiring terminals which include: 117 VAC power input, 24 VDC battery backup power input, 4-20
mA signal output and alarm relay dry contacts. Internal panel mount fuses are provided for VAC and VDC power.
A power switch, power indicator lamp, and a flow fault indicator lamp are mounted on the hinged gasketed door.
Externally mounted flow controls include a selector valves for sample and calibration and a flow meter with adjustable
valve.
A unique characteristic of the 971-041170-00K is its teflon fittings and tubing. The teflon flow path, unlike stainless
steel or aluminum, is resistant to adsorption of chlorinated gases and ammonia. This prevents the loss of the sample and
thereby provides a more accurate detection method.
1.1 INSTALLATION
1. Securely mount the enclosure in accordance with the drawing below. Mounting holes are 5/16" diameter.
Detcon Model 971-041170-00K Gas Detection System PG.2
2. Install a length of tubing from the desired sample point to the sample port as shown below. Sample draw tubing should be
Sample Port
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detcon inc.
H
OUS TO N, TE X AS
SAMPLE DRAW
GAS DETECTION SYSTEM
VENT
SET
FLOW
CAL
IN
C
L
O
S
E
O
P
E
N
SAMPLE
V
ALVE
C
L
O
S
E
O
P
E
N
Vent Port
teflon 1/8 or 1/4" OD. Sample flow rates are set between 500 and 1000 ml/m.
CAUTION: When detecting for NH3, CL2, CLO2, HF, or HCL care must be taken to avoid use of stainless steel tubing and
connections because stainless steel readily adsorbs these gases and will cause significant error in the detection process. Teflon
tubing is recommended for these applications.
3. Install a length of tubing from the vent port to an area deemed safe for vent as shown above.
Detcon Model 971-041170-00K Gas Detection System PG.3
Caution: Observe correct polarity when terminating all input/output wiring. Failure to do so may result in circuit dam-
P7 P8P6P5
L1 L2
GND
mA C
NO/NCCNO/NCCNO/NC
117 VACIN24 VDC
IN
Battery
Backup
SENSOR #1 FAULT
ALARM CONTACTS #1
ALARM 1 ALARM 2
A
LARM DRY
CONTACTS
COM
NO/NC
COM
COM
NO/NC
NO/NC
FLT
ALM 1 ALM 2
Flow
Fault
Circuit
COM
NO
NC
1
COM
NO
NC
2
COM
NO
NC
3
PT1
m
A
4-20mA
Wire alarms and the 4-20mA output
signal to the plug-type connectors.
Wire 117 VAC & optional 24 VDC
backup to the lugless connectors.
Two discreet form C dry contacts
are provided (2 & 3) by the flow
fault circuit for alarm devices. The
f
irst set of contacts (1) are
prewired to interrupt the 4-20mA
signal output in the event of a
flow fault. This will allow for flow
fault monitoring at any
contr oller/com puter that the signal
is wired in to.
FLOW
FAULT
CONTACTS
age on power up. See the field wiring diagram below for terminal locations.
4. Connect 117VAC to the connector labeled “117VAC IN”.
5. If applicable, connect 24 VDC battery backup to the connector labeled “24 VDC IN”.
6. If applicable, connect a remote recording device, or computer to the 4-20 mA signal output connector. The terminals
are labeled SENSOR “–” and “mA”.
7. If applicable, connect alarm devices. Discrete alarm relay contacts are provided for three alarms: Fault, Low and
High. The contacts consist of common and choice of normally open or normally closed. Contact output selections are
jumper programmable on the sensor connector board. See the sensor manual for contact ratings and other information.
8. If applicable, connect flow fault alarm wiring. Two sets of form C contacts (common, normally open and normally
closed) are provided. Relay contacts are rated 1 amp at 30VDC/.24 amp at 125VDC.
1.2 START UP
Upon completion of all tubing connections and field wiring turn on the power switch located on the enclosure door.
Note that the power lamp illuminates. If applicable, note that the sensor LCD indicators activate. Varying readings may
occur during sensor warm-up. Allow approximately 1 hour to stabilize (24 hours is best).
Also note air flow through the flow meter. Adjust the flow meter as necessary so that it falls between 500 and 1000
ml/m (milli liters per minute). The normal configuration of the flow valves should be: “CAL IN” closed (horizontal
position); “SAMPLE VALVE” open (vertical position).
Detcon Model 971-041170-00K Gas Detection System PG.4
Assure that all field tubing connections are secure by obstructing the end of the sample line and observing that the
flow meter decreases to “0” flow.
1.3 FLOW FAULT DETECTION
Flow fault detection consists of a flow fault circuit assembly located inside the enclosure and a door mounted fault indicator lamp. If the air flow falls below a predetermined set point the following will occur: the flow fault alarm relays will
energize; an LED indicator mounted on the flow fault PCB will illuminate; the door mounted flow fault lamp will illuminate; the 4-20mA signal will be opened via relay #1 on the flow fault circuit board (this will allow for flow fault programming at the remote recording device or computer).
Because the pressure inside the sample and vent flow tubing differs according to the tubing length , the flow fault
circuit will require calibration after installation.
To calibrate the flow fault circuit, first determine at what point it is desired that the flow fault circuit is activated.
Typically, air flow should range between 500 and 1000 ml/min. (milliliters per minute) as seen on the flow meter located
on the left of the enclosure. It is recommended that the flow fault circuit be set to activate at a flow of approximately
200 ml/m.
To adjust the flow fault first set the air flow at the point where you want the fault condition to activate. Next turn
the flow fault adjust potentiometer (PT1 as seen in the illustration on the previous page) clockwise until the flow fault
LED illuminates and its relays fire. Make adjustments as necessary by increasing and decreasing airflow until the flow
fault function occurs at the desired set point. Once the flow fault circuit has been set, return the air flow to between 500
and 1000 ml/m.
NOTE: Because sample and vent tubing can become congested over a period of time, the flow fault function should be
checked periodically and adjusted as necessary.
1.4 CALIBRATION
Model 971-041170-00K sensor assemblies are calibrated prior to shipment and should therefore require minimal adjustment at time of commissioning. However, it is recommended that a complete calibration be performed on a periodic
basis to assure optimum system performance. Refer to the sensor instruction manual for gas type, range and sensor specific calibration instructions.
Note that the sensor instruction manual requires the removal of rain/splash guards for the application of gas. This
requirement will be superceded by the instructions below. The calibration adapter attached to the sensor head should
not be removed during calibration.
Required material:
1. Span gas cylinder containing gas as per instructions in the sensor instruction manual.
2. 1/4" Tee tubing fitting as shown in the illustration on the following page.
To Calibrate: (refer to illustration on the following page)
1. As shown in the illustration on the following page, turn the “CAL IN” valve counter-clockwise so that the handle is in the
vertical position. Next turn the “SAMPLE VALVE” clockwise so that the handle is in the horizontal position. The sample is
now being drawn from the CAL port.
2. Using the 1/4" Tee assembly, connect the span gas cylinder to the calibration port. Note that the cylinder flow rate
should be 500 ml/m while the sample draw flow rate should be adjusted to 400 ml/m. This will assure that the sample is
not diluted.
NOTE: The 1/4'' Tee and vent tube is not necessary when using a demand flow regulator. Set flow via rotameter to 500
cc/min when using the demand flow regulator.
3. Follow the calibration instructions given in the sensor instruction manual.
4.
Close cylinder valve to allow clearing/zero stability. Note that zero and span functions may interact slightly with one
another on a 400 series sensor. If using a 400 series sensor, zero and span tests may be repeated 2 or 3 times as necessary.
Detcon Model 971-041170-00K Gas Detection System PG.5
5.
6" of
vent
t
ube
Calibration
Port
F
ixed flow
regulator
Span gas
cylinder
Te fl o n
tubing
1/4"
Te e
400 ml/m
500
ml/m
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detcon inc.
HOU ST ON , T EX AS
SAMPLE DRAW
GAS DETECTION SYSTEM
SET
FLOW
CAL
IN
C
L
O
S
E
O
P
E
N
S
AMPLE
VALVE
C
L
O
S
E
O
P
E
N
VENT
100 ml/m
N
OTE: The 1/4'' Tee and vent tube
is not necessary when using a
demand flow regulator. Set flow via
rotameter to 500 cc/min.
When calibration is complete return the two valves to their previous positions: the “CAL IN” valve clockwise so that the
andle is in the horizontal position and the “SAMPLE VALVE” counter-clockwise so that the handle is in the vertical position.
h
1.5 RFI PROTECTION
Model 971-041170-00K gas detection system is protected from RFI (radio frequency interference) via a circuit located
within the 3/4” pipe that connects the sensor to the fiberglass enclosure. This circuitry and all interconnecting wires are
epoxy potted within the pipe and require no service.
1.6 SPARE PARTS
Part# Description
284-000000-000 Power switch
284-200000-000 Power indicator lamp
284-100000-000 Flow fault indicator lamp
500-005151-002 Flow fault circuit assembly
351-152021-200 24 VDC pump
348-900000-000 1000 ml/m flow meter with valve
360-6SD1SD-200 117VAC to 24VDC power supply assembly
943-200000-0SS In-Line activated carbon scrubber (Re-place Bi-Annually)
1.7 WARRANTY
Detcon Inc., as manufacturer, warrants under intended normal use each new Model 971-041170-00K gas detection system to be free from defects in material and workmanship for a period of one year from the date of shipment to the original purchaser. Sensor assembly warranties are explained in their respective instruction manuals. All warranties and service policies are FOB the Detcon Inc. facility located in The Woodlands, Texas.
Detcon Model 971-041170-00K Gas Detection System PG.6
1.11 FLOW DIAGRAM
Flow
Meter
Set
500-1000
ml/m
P1 P2
PUMP
Flow
Switch
Note: All tubing upstream
of the gas sensor is Teflon.
All interior downstream
tubing is PVC.
VENT
SENSOR
CAL
Sample
Activated
Carbon Scrubber
Detcon Model 971-041170-00K Gas Detection System PG.7
1.12 WIRING DIAGRAM
P6
24
VDC IN
Chassis GND
Mounting Screw
P5
117
VAC IN
P4
220 VAC IN
L2L1L2L1 NEU
F1 DC
Fuse 2A
Power
Switch
Power
Lamp
Flow Fault
Lamp
mA
P7
Sensor #1
P8
Sensor #1 Alarms
C
NO/NC
C
NO/NC
C
NO/NC
P9
Sensor #1
RS-485
SHLD
mA
P10
Sensor #2
P11
Sensor #2 Alarms
C
NO/NC
C
NO/NC
C
NO/NC
SHLD
P12
Sensor #2
RS-485
Optional Controller
Fault Alarm 1 Alarm 2 Fault Alarm 1 Alarm 2
Optional Controller
D2
1N4001
D1 1N4001
P13
+FFL
–FFL
+PL
–PL
C
NO
C
NO
J1 J2 J3 J4
J5
P15
F2 AC
Fuse 1A
F2
F2
F1F1
L2L1
Pump
P1 P2
RED
BLK
W
HT
B
LK
G
RN
CNO
P13
Flow
Fault
COMNONC
1
COMNONC2COMNONC
3
+24V
DC COM
PT1
L2L1
P3
Power
Supply
3
1 4
2
+O +S –S –O
Red 18
Blk 18
Blk 18
Wht 18
Red 22
Blk 22
Blk 18
Blk 18
Red 18
Blk 18
Blk 18
Red 18
Blk 18
Red 18
Blk 18
Red 18
Blk 18
Blk 18
Red 18
Red 18
Mailing address: P.O. Box 8067, The Woodlands, Texas 77387-8067 ❏ Phone: (281) 367-4100 ❏ Fax: (281) 298-2868
Shipping address: 3200 A-1 Research Forest Dr., The Woodlands, Texas 77381
Detcon Model 971-041170-00K Gas Detection System PG.8
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