Dwyer Instruments CMS300 Installation and operating instructions

Model CMS300 Carbon Monoxide Transmitter and Switch
Specications - Installation and Operating Instructions
Bulletin AQ-CMS300
The Model CMS300 Carbon Monoxide Transmitter and Switch provides a eld
selectable current or voltage output that is proportional to the carbon monoxide
concentration in underground parking garages, vehicle maintenance facilities, or
mechanical rooms. An integral relay can be used for alarm conditions and is congured
with preset jumper selectable ranges of 25, 60, or 150 PPM. Field calibration can
be done by using Dwyer Instruments Model GCK-200CO-2000CO2 calibration gas,
Model A-507 calibration adapter, and the on-board zero and span potentiometers.
INSTALLATION
• The transmitter should be mounted at normal breathing height, approximately 5 to
6 ft above the oor.
• The unit may be mounted in the horizontal or vertical position. It should be
mounted in an area that is shielded from direct contact with the elements or direct
sunlight.
• Mount in an area that will prevent the sensor from having any direct contact with
water.
• The unit should be placed in an area that will give an average of the air quality. Do
not place the unit so it will receive direct engine exhaust. Prolonged exposure to
direct engine exhaust may damage the sensor.
MOUNTING
1. Remove the cover plugs from the face of the unit and the top cover.
2. Remove the desired conduit tting knock out and install conduit tting (not
provided).
3. Position the transmitter where it is to be mounted and mark the mounting holes in
each corner of the housing.
4. Drill or punch out marked locations.
5. Place the transmitter box over mounting holes on wall and align. Install wall mount
screws (not provided) in mounting holes.
6. Proceed with all wiring according to Figures 1 through 4.
7. Replace cover and cover plugs on the face of the unit.
SPECIFICATIONS
Sensor: Electrochemical, 5 years typical lifespan.
Range: 0-300 PPM.
Output Drift: <5% per year in air.
Temperature Effect: ±2% over range.
Coverage Area: 7,500 ft2 (700 m2) or 50 ft (15 m) radius.
Accuracy: ±5 PPM or 5% of reading for 0-300 PPM (whichever is greater).
Resolution: 1 PPM.
Temperature Range: -4 to 122°F (-20 to 50°C).
Storage Temperature: For best sensor life, 32°F to 68°F (0 to 20°C).
Humidity Range: 15-90% RH constant; 0-99% RH intermittent.
Response Time: <45 s to 90% of nal value.
Calibration: 15 turn span and zero adjustment potentiometers.
Housing: UV resistant glass lled polycarbonate.
Analog Output: Jumper selectable 4-20 mA (loop powered) or 2-10 V (max. load
2 kΩ).
Enclosure Rating: IP64.
Switch Type: Single-pole double-throw (SPDT).
Relay Electrical Rating: 30 VDC, 250 VAC. N/O=5 A. N/C=3 A resistive.
Set Point: Jumper selectable 25, 60, or 150 PPM.
Set Point Differential/Hysteresis: 3% of scale.
Relay Action: Factory set for direct acting.
Weight: 1 lb (0.45 kg).
Compliance: Sensor is UL recognized component for ANSI/UL-2034, UL-2075,
E340403, CE.
These are general guidelines. Local laws or ordinances will
take precedence.
NOTICE
Disconnect power supply before installation to prevent electrical
shock and equipment damage. Make sure all connections are in
accordance with the job wiring diagram and national and local electrical codes. Use
copper conductors only.
WARNING
Use electrostatic discharge precautions (e.g., use wrist straps)
during installation and wiring to prevent equipment damage.
Avoid locations where mechanical shock or vibration, excessive
moisture or corrosive fumes are present.
Do not exceed ratings of this device; permanent damage not
covered by warranty may result. The 4-20 mA wiring congurations
are not designed for AC voltage operation.
CAUTION
CAUTION
CAUTION
DWYER INSTRUMENTS, INC.
P.O. BOX 373 • MICHIGAN CITY, INDIANA 46360, U.S.A.
Phone: [phone]
Fax: [phone]
www.dwyer-inst.com
e-mail: [email protected]
5-7/64
[129.78]
3-45/64 [94.06] 2-15/64
[56.75]
3-1/8 [79.38]
4-17/32
[115.09]
3-1/8 [79.38]
4-17/32
[1
15.09]
4X Ø13/64 [5.16]
MOUNTING HOLES
®

WIRING
Use 22-16 AWG wire for wiring to the terminal blocks. Refer to Figures 1 through 4 for
wiring information. The terminal blocks are removable for ease of installation. Please
see Figure 1 below for the layout of the board within the CMS300 unit.
Power Wiring
The unit may be powered by 12-40 VDC or 15-32 VAC. For DC power, wire positive
(+) to terminal 1 and negative (-) to pin 2 terminal block P1. For AC power, wire to
terminals 1 and 2. See Figure 2.
Relay Wiring
Maximum relay load is 30 VAC/VDC. N/O = 5A. N/C = 3A. Wire to terminal block P2
as shown in Figure 2.
Setting the Output for 4-20 mA or 2-10 V Output
Prior to wiring the 4-20 mA or 2-10 V output, verify that the IOUT/VOUT jumper, located
just behind the four terminal block P1, is in the correct position. For 4-20 mA output, the
two right most pins are shorted. For 2-10 V output the two left most pins are shorted.
See Figure 3 for examples.
4-20 mA and 2-10 V Output Wiring
Wire to terminal block P1, positive (+) to terminal 4 and negative (-) to terminal 3 as
shown in Figure 2. For 4-20 mA output, the maximum load resistance is 600 Ω. For
2-10 V output, the minimum load resistance is 2000 Ω, or 5 mA maximum. See Figure
2.
Setting the Relay Trip Point
The relay may be set to turn on (turn on means the relay N/O contacts close) at 25, 60
or 150 PPM. The relay has N/O and N/C contacts available. Place the shorting jumper
across the appropriate pins of J3 as shown in Figure 4.
RELAY WIRING
N/O N/C
COM
1 2 3 4
1 2 3
P1
P2
POWER
SUPPLY RECEIVER
+-
+-
2-20 mA 2-10 V
25 PPM 60 PPM
25 PPM 60 PPM
150 PPM
25 PPM 60 PPM
150 PPM
25 PPM 60 PPM
150 PPM
150 PPM
Figure 1: Circuit board layout
Figure 2: Current and voltage output and relay wiring
Figure 3: Output jumper positions
Figure 4: Relay jumper positions
Sensor mounts in
these two pins
Current/voltage
jumper selection
CO sensor
Relay setpoint
jumper selection
Calibration
potentiometers

CALIBRATION
Calibration of the Model CMS300 requires an A-507 calibration adapter, model GCK-
200CO-2000CO2 calibration gas, a multimeter, and a small at head screw driver.
1. Turn off power to the transmitter.
2. Remove the lid from the housing.
3. Replace the receiver shown in Figure 1 and 2 with a multimeter and restore the
power to the transmitter.
4. Attach the tubing from the zero calibration gas to the A-507 calibration adapter.
5. Securely attach the A-507 to the CMS300 as shown in Figure 3.
6. Allow the calibration gas to ow at a rate of 0.5 to 1.0 slpm for at least 3 minutes.
7. Adjust the zero potentiometer in Figure 6 until the output reading on the
multimeter reads 4 mA or 2 VDC (depending on output selection).
8. Repeat steps 4 through 6 using the span calibration gas.
9. Adjust the span potentiometer in Figure 6 until the output reading on the
multimeter reads 14.67 mA or 7.33 VDC (depending on output selection).
10. Turn off the power to the transmitter.
11. Replace the multimeter with the receiver as shown in Figures 1 and 2 and restore
the power to the transmitter.
12. Remove the A-507 calibration adapter.
13. Replace the lid on to the transmitter.
Sensor Replacement
A replacement sensor is available from Dwyer Instruments, Inc. Order part number
A-505 for a replacement CO sensor.
1. Remove the cover plugs from the face of the unit and top cover. Locate the
sensor, see Figure 1 – the sensor is mounted on three pin sockets. Remove and
discard the sensor.
2. Remove the shorting wire spring located on the bottom of the new sensor.
3. Install the new sensor into the four pin sockets. Note – the sensor has two pins,
which are shown in Figure 1. The third and fourth pin on the board is for the
stability of the sensor.
4. The unit must be re-calibrated whenever a new sensor is installed.
5. Allow 30 minutes for the unit to come to temperature equilibrium prior to
calibration. The unit has internal temperature compensation, and the sensor must
be at the same temperature as the unit to calibrate properly.
MAINTENANCE/REPAIR
Upon nal installation of the Model CMS300 Transmitter, as with all electrochemical
type gas sensors, routine calibration is required. It is recommended that units be re-
calibrated at 6 month intervals, to maintain the published accuracy, or as required by
local ordinances or other requirements. The units will maintain 5% accuracy if they are
re-calibrated at 12 month intervals.
Except for sensor replacement and calibration, the Model CMS300 is not eld
serviceable and should be returned if repair is needed (eld repair should not be
attempted and may void warranty). Be sure to include a brief description of the
problem plus any relevant application notes. Contact customer service to receive a
return goods authorization number before shipping.
WARRANTY/RETURN
Refer to “Terms and Conditions of Sale” in our catalog and on our website. Contact
customer service to receive a Return Goods Authorization number before shipping the
product back for repair. Be sure to include a brief description of the problem plus any
additional application notes.
The electrochemical sensors should be stored in an
environment with a minimum humidity level of 20% RH. If the
sensor dries out, replacements will not be covered under warranty, but they can be
revived by allowing them to stabilize in an environment above 40% RH for 10 days.
Once revived, they need to be recalibrated before use.
NOTICE
If the span potentiometer on the Model CMS300 cannot
restore the output to 14.67 mA, the sensor will need to be replaced.
NOTICE
Sensors contain acid. Do not attempt to open sensors.
Sensors should be disposed of according to local laws.
CAUTION
Figure 5: Circuit board mounting screws
Figure 6: Calibration controls
Zero
Span

Printed in U.S.A. 2/22 FR# 444503-00 Rev. 3©Copyright 2022 Dwyer Instruments, Inc.
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DWYER INSTRUMENTS, INC.
P.O. BOX 373 • MICHIGAN CITY, INDIANA 46360, U.S.A.
Phone: [phone]
Fax: [phone]
www.dwyer-inst.com
e-mail: [email protected]