AMC 1ACO User manual

Gas Monitor
1ACO
One-Channel Gas Monitor
INSTRUCTIONS
Installation and Operation of the
Gas Monitor 1ACO One-Channel Monitor
IMPORTANT:
Please read these installation and operating instructions completely
and carefully before starting.
Filename: 3221405A.doc Copyright © July 2009, AMC
The Armstrong Monitoring Corporation
215 Colonnade Road South, Ottawa, Ontario, Canada K2E 7K3
Tel: [phone] • Fax: [phone] • Canada & U.S. Toll Free: 1-800-465-5777
E-mail: [email protected] • Internet: www.armstrongmonitoring.com

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TABLE OF CONTENTS
Section Title Page
1WARRANTY..........................................................................................................................3
1.1 LIABILITY.......................................................................................................................3
1.2 PRODUCT RETURN......................................................................................................3
1.3 MODIFICATIONS AND SUBSTITUTIONS.....................................................................3
2PRODUCT INFORMATION...................................................................................................4
3PRODUCT DESCRIPTION ...................................................................................................5
3.1 GENERAL DESCRIPTION.............................................................................................5
3.1.1 MONITOR FEATURES ...........................................................................................5
4INSTALLATION ....................................................................................................................8
4.1 MOUNTING INSTRUCTIONS........................................................................................8
4.2 WIRING..........................................................................................................................9
4.2.1 MONITOR WIRING.................................................................................................9
4.2.2 AMC-S2e Connection............................................................................................10
4.3 DIP SWITCH PROGRAMMING ...................................................................................11
4.4 ALARM RELAY PROGRAMMING ...............................................................................13
4.5 AUDIO ALARMS ..........................................................................................................13
5OPERATION AND CALIBRATION.....................................................................................14
5.1 POWER-ON DELAY.....................................................................................................14
5.2 TEST SWITCH FUNCTION..........................................................................................14
5.3 ACKNOWLEDGE FUNCTION......................................................................................14
5.4 ALARM/WARNING RELAY ACTIVATION DELAYS ....................................................14
5.5 RELAY OUTPUTS........................................................................................................14
5.6 CALIBRATION/SERVICE.............................................................................................15
5.6.1 Equipment Required..............................................................................................16
5.6.2 Calibration.............................................................................................................16
6PREVENTIVE MAINTENANCE ..........................................................................................19
6.1 GENERAL ....................................................................................................................19
6.2 SCHEDULED CALIBRATION ......................................................................................19
6.3 SENSOR REPLACEMENT ..........................................................................................19
7INSTALLATION TIPS AND TRICKS ..................................................................................20

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1WARRANTY
The AMC-1ACO one-channel monitor is warranted against defects in material and workmanship
for a period of two (2) years from date of shipment (except electrochemical sensor elements,
catalytic elements and portable monitors – one (1) year – refer to individual spec sheets for
additional exceptions). Calibration is not warranted. During the warranty period, Armstrong
will repair or replace components that prove to be defective in the opinion of Armstrong
Monitoring. The corporation is not liable for auxiliary interfaced equipment, nor consequential
damage.
NOTE: Any substitution or tampering with components without expressed, written permission of
ARMSTRONG MONITORING may result in intrinsic damage which will cancel the effectiveness
of the warranty. Extended warranties are available through the factory. Please contact factory.
Service agreements may supersede standard warranty terms.
1.1 LIABILITY
All Armstrong Monitoring systems shall be installed by a qualified technician and maintained
according to Armstrong Monitoring Installation and Maintenance Manual instructions.
Armstrong Monitoring shall not be responsible for any liability arising from auxiliary interfaced
equipment, consequential damage, the installation, or the operation of this equipment.
Armstrong’s total liability is contained in the warranty conditions stipulated above. No other
acceptance of liability is expressed or implied by Armstrong Monitoring. Except as set forth
herein, Armstrong Monitoring makes no warranty, expressed or implied, with respect to the
fitness for any particular purpose or use or otherwise of the products or services, or on any parts
or components or labour furnished as part of the sale. In no event shall Armstrong Monitoring,
its officers, directors, employees, agents or servants be liable to the buyer or any other party for
any loss of profit, loss of use, incidental, consequential or special damages arising out of the
sale, delivery, servicing, use, loss of use, of the products or of any part thereof, irrespective of
whether Armstrong Monitoring or any of its officers, directors, employees, agents or servants
has advanced notice of the possibility of such damages. In no event will the total liability to the
buyer exceed the sum paid to Armstrong Monitoring by buyer for the products and services.
1.2 PRODUCT RETURN
All products that must be returned for warranty service will be shipped by prepaid freight and will
only be accepted with a Returned Materials Authorization (RMA) number issued by
ARMSTRONG MONITORING. Goods returned to the client will be by freight collect.
1.3 MODIFICATIONS AND SUBSTITUTIONS
Due to an ongoing development program, Armstrong Monitoring reserves the right to modify the
design and substitute components in any of its products without prior notice. All changes are at
the sole discretion of Armstrong Monitoring, and the corporation shall not be liable for any cost
arising out of such modifications or substitutions that may be incurred by the user.

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2PRODUCT INFORMATION
Monitor Serial Number. ………………..………………..
AMC-S2e Serial Number…………………………………
Alarm Trip Points…………………………………………. Warning _______________________
Alarm________ _________________
Full Scale Concentration…………………………………
Power Supply Requirement. ………………….……..… 120 VAC, 60 Hz, 30 VA
Operating Temperature.…….………………….……..… -20°C to +40°C (-4°F to +104°F)
Operating Pressure..…………….…………….……..….. Ambient atmospheric pressure
Relative Humidity..…………….…………….……..…….. 35 – 85% non-condensing.
TORQUE SPECIFICATIONS:
POWER SUPPLY:
Neutral terminal screw ……………………………………………………………… 7 pound-inches.
Hot terminal screw …………………………………………………………...……... 7 pound-inches.
Ground Lug screw. …………………………………………………………………. 15 pound-inches.
RELAY:
Relay socket terminal screws ……………………………………………………… 7 pound-inches.
Note:
All Armstrong Monitoring systems must be installed and maintained according to
instructions, to ensure proper operation. Only qualified technicians should install and
maintain the equipment.

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3PRODUCT DESCRIPTION
3.1 GENERAL DESCRIPTION
The Gas Monitor 1ACO monitor is a one channel gas monitoring system incorporating state of
the art sensing technology using micro-controller based design to provide continuous, reliable
surveillance of surrounding air for traces of hazardous gases (listed in Section 2). The monitor
comes with the following features, see Figures 1 and 2.
3.1.1 MONITOR FEATURES
1. RUN/FAULT/OFF INDICATOR: A green LED
RUN: LED on
FAULT: LED flashing
OFF: LED off
2. WARNING INDICATOR: Warning levels of gas are indicated by a yellow LED.
Warning concentrations are indicated in Section 2
3. ALARM INDICATOR: Alarm levels of gas are indicated by a red LED. Alarm
concentrations are indicated in Section 2
4. POWER TERMINAL BLOCK: For line voltage connections of 120 VAC, 60 Hz
5. TRANSFORMER: A Class II, step down transformer powers the internal
circuitry and remote sensor at low voltages. Located
underneath the PCB
6. INTERNAL WIRING HEADER: Provides wiring connection points as follows:
1,2,3 - Relay coils
4,5,6,7,8 - Reserved
9,10 - Acknowledge switch
11,12 - Audio alarm indicator
7. AUDIO ALARM INDICATOR: The buzzer will activate for Alarm, Warning
(configurable) and fault conditions, with a distinct tone
for each one
8. RELAY SETUP JUMPERS: Used to independently configure the Warning and Alarm
relays as Normally Energized or Non-Energized
9. TEST SWITCH: The test switch is provided to electronically simulate
alarms in order to test audio and relay functions
10. TRIP POINT ADJUSTMENT: Sets the Signal adjust, Alarm and Warning

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11. PROGRAMMING DIP
SWITCHES: Allows user to configure the alarm delay and timer circuits, audio alarm activation, sensor mode selection,
fault threshold, and acknowledge switch function
12. RELAYS: 2 alarm DPDT relays are provided
13. ON-BOARD AMC-S2e
SENSOR: Sensor allows local detection of gas
FIGURE 1: Gas Monitor 1ACO, Front Cover.

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9. TEST SWITCH
10. TRIP POINT ADJUSTMENT
7. AUDIO ALARM
INDICATOR
5. TRANSFORMER
(UNDER PCB)
11. PROGRAMMING
DIP SWITCHES
8. RELAY SETUP
JUMPERS
6. INTERNAL WIRING
HEADER
4. POWER TERMINAL
13. ON-BOARD AMC-S2e SENSOR
12. RELAYS
BLOCK
FIGURE 2: Internal Features of the Gas Monitor 1ACO.

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4INSTALLATION
Follow the guidelines in this section for proper locations and installation of the Gas Monitor
1ACO. In addition to these instructions, ensure installation is compliant with local building and
electrical codes. This section covers topics related to installation location, mounting, cable
selection, wiring instructions and monitor function programming for the Gas Monitor 1ACO.
4.1 MOUNTING INSTRUCTIONS
Securely fasten the Gas Monitor 1ACO unit on a solid, non-vibrating surface or structure. Install
the unit where it is not exposed to rain or water spray. Install in an area where the local
concentration of gas is unaffected by the presence of ventilation systems and away from
sources of interference gases. Mount the monitor where the unit can be observed periodically.
For most applications the monitor should be mounted 1.2 -1.8 m (4-6 ft) from the floor. See
Figure 3 for mounting hole locations.
CAUTION: All cable entry MUST BE through the BOTTOM of the monitor enclosure only.
Other entry locations will allow foreign materials to enter the enclosure, causing possible
damage to the internal components.
FIGURE 3: Locations of Mounting Holes.

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4.2 WIRING
4.2.1 MONITOR WIRING
POWER SUPPLY: The monitor operates on 120 VAC, 60 Hz. A Class II step down
transformer runs the internal circuitry at low voltages. The power
supply connections are made at the power terminal block located
inside the monitor, see Figure 4.
RELAYS: Relays are included with the monitor, DPDT relays are used. The two
relays are set for different alarm conditions. The contacts are rated for
10Amps@250VAC resistive. For relay contact arrangement, see
Figure 5.
The Gas Monitor 1ACO is shipped factory configured to be de-energized in the non-alarm state.
If the user prefers to have relays in a normally energized (failsafe) state see section 4.4 for
jumper configuration.
AC PRIMARY
120 VAC, 60 Hz
NEUT.
HOT
GND
FIGURE 4: Location of Power Supply Connections.

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FIGURE 5: Relay Contact Arrangement.
4.2.2 AMC-S2e Connection
The AMC-S2e sensor is designed to plug into the same socket as the solid state sensor. Plug
the sensor into the socket and ensure the green LED on the AMC-S2e illuminates. If the green
LED does not illuminate, unplug and rotate AMC-S2e 180º.
FIGURE 6: S2e sensor connection.
Insure that JB8 jumper is in the MD-V setting. Refer to Figure 7 for more information.

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JB8
JB10
MD-V
SS 4-20mA
V+ +5V
SENSOR 1
JB8 JB10
SS =
MD-V =
4-20mA =
V+ =
+5V =
FIGURE 7: Signal input configuration jumpers.
4.3 DIP SWITCH PROGRAMMING
The circuit board has two blocks of DlP-switches for configuring the various functions; see
Figure 2, item 11. Each DIP-switch can be set to OFF (left position) or ON (right position)
depending on functions required.
Table 1: DIP-switch programming chart
Switch Feature Position Description
OFF Warning and alarm relays are automatically de-activated
once activating condition has been removed and
minimum run timer has expired.
SW1-1 Activate
Alarms until
Acknowledge
(Latching
Relays) ON Once activated, warning and alarm relays remain
activated (latched) until activation condition has been
removed, minimum run timer has expired and the
Acknowledge button has been pressed.

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Switch Feature Position Description
SW1-2,
SW2-2
Minimum Run
Timer See Description Warning and alarm relays are maintained in alarm state
for a minimum time interval following alarm activation, as
follows:
SW1-2 SW2-2 Minimum Run Time
OFF OFF 0 minutes
ON OFF 5 minutes
OFF ON 10 minutes
ON ON 30 minutes
Note that a sensor level falling below the alarm threshold
and then re-occurring during this time resets the alarm
timer for the associated alarm.
SW1-3,
SW1-4
Sensor Type
(Mode
Select)
See
Description Sensor type (threshold mode) is selected as follows:
SW1-3 SW1-4 Sensor Type (Mode)
OFF OFF Increasing
ON OFF Decreasing
OFF ON Reserved
ON ON Reserved
OFF The Alarm relay is not activated when fault is detected.
SW2-1 Alarm Relay
Activated
when Fault is
Detected ON When fault is detected, the Alarm relay is activated.
OFF Audio alarm is disabled for Warning conditions.SW2-3 Audio Enable
for Warning ON Audio alarm is activated in conjunction with Warning.
OFF Sensor Fault thresholds set at 0.4 mA into 250R or 100
mV.
SW2-4 Sensor Fault
Threshold
ON Sensor Fault thresholds set at 1.4 mA into 250R or
350mV.
OFF No activation delay of Warning conditions.
SW2-5 Activation
Delay,
Warning ON Five minute delay on activation of Warning conditions
following sensor exceeding alarm threshold.
OFF No activation delay of Alarm conditions.
SW2-6 Activation
Delay, Alarm ON Delay on activation of Alarm conditions following sensor
exceeding alarm threshold.
OFF Audio alarm (buzzer) disabled.SW2-7 Audio Alarm
Enable ON Audio alarm (buzzer) enabled.

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4.4 ALARM RELAY PROGRAMMING
The WARNING and ALARM relays may be configured as normally energized or normally de-
energized with the jumper straps identified in Table 2 WARNING and ALARM Relay Active
State and shown in Figure 2, item 8. Typically the “normally de-energized” position is
employed, activating the relay when an alarm condition is detected.
The “normally energized” position is selected when failsafe operation is required. For example,
the requirement is that when power to the Gas Monitor is lost, the load connects to a power
source via contacts of this, normally energized relay.
Table 2: WARNING and ALARM Relay Active State
Relay Jumper Normally
De-Energized Normally Energized
Warning JB11 1-2 2-3
Alarm JB12 1-2 2-3
4.5 AUDIO ALARMS
An audio alarm output is provided, which produces various alarm sounds, as shown in the chart
below. The audio alarm can be disabled by turning OFF the DIP-switch SW2-7.
Table 3: Audio alarm operation
Sensor Status Output
Normal off
Warning (SW2-3 OFF) off
Warning (SW2-3 ON) two long, slow beeps.
followed by short pause
Alarm four fast beeps, followed
by short pause
Any Sensor Fault short, slow beeps
Notes:
1) Micro-controller operation ensures that Warning, Alarm and
Fault conditions will not occur simultaneously on the same sensor.

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5OPERATION AND CALIBRATION
This section covers the operation and calibration procedures pertaining to the Gas Monitor
1ACO.
5.1 POWER-ON DELAY
Following successful completion of all self-tests, detection of sensor WARNING, ALARM and
FAULT conditions is disabled for 30 seconds. This delay is provided to allow the sensors to
stabilize. During this delay, the status LEDs show the “sensor normal” condition (only the green
LED on). The audio alarm is silent, and the alarm relay outputs are held in the non-alarm
condition.
5.2 TEST SWITCH FUNCTION
While pressed, the on-board test switch will cause continuous activation of the alarm relay
outputs (energized or de-energized, depending on configuration), continuous activation of the
audio alarm, and all status LEDs will be illuminated. Sensor processing and updating of internal
status and timers continues. When released, the outputs and LEDs return to normal operation.
5.3 ACKNOWLEDGE FUNCTION
An option exists for an Acknowledge pushbutton switch. When pressed, any present
WARNING, ALARM or FAULT condition, including those previously acknowledged, will be
silenced (audio alarm off) for 30 minutes. If any WARNING, ALARM or FAULT condition
remains after 30 minutes, the audio alarm will again be activated. Any WARNING, ALARM or
FAULT condition returning to normal and then reactivating, or any new WARNING, ALARM or
FAULT condition will cause an immediate audio alarm.
If the Activate Alarms Until Acknowledge (latching relays) (SW1-1 ON) feature is enabled, the
alarm outputs will not automatically return to normal, but will remain in alarm until the
acknowledge button has been pressed. While a relay remains latched, the audio alarm remains
active.
5.4 ALARM/WARNING RELAY ACTIVATION DELAYS
The Gas Monitor 1ACO comes standard with 5 min activation time delays for the WARNING
and ALARM relay contacts. The activation time delays can help prevent short cycling
WARNING/ALARM in some applications. The delays can be enabled by turning ON switches
SW2-5 and SW2-6, for WARNING/ALARM respectively.
5.5 RELAY OUTPUTS
A WARNING condition on either sensor will result in activation of the WARNING relay output.
An ALARM condition on either sensor will result in activation of both the WARNING and ALARM
relay outputs.

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Each alarm relay (WARNING, ALARM) may be selected as either energized when alarm active,
or de-energized when alarm active, using on-board jumpers JB11, JB12, respectively. This
option is provided to allow configuration flexibility. If configured to energize the relay when alarm
becomes active (jumpers set to “normally de-energized”), a controller failure or controller power
failure will prevent an alarm condition from being produced. The opposite setting of jumpers
(relay “normally energized”) will result in an alarm condition produced on reaching the gas
threshold level, controller failure or controller power failure.
5.6 CALIBRATION/SERVICE
The Gas Monitor 1ACO and AMC S2e (CO) comes factory calibrated and does not need to be
adjusted as part of installation and should be ready for operation after installation and a 30
minute stabilization time.
Subsequent calibration is required as a part of regular maintenance, and when replacing the
sensor. See section 6 Preventive Maintenance of this manual for the recommended calibration
schedule.
Caution:
- Only qualified personnel should perform the actual calibration.
- Users new to gas calibration are advised to consult with Armstrong Monitoring
The Armstrong Monitoring Corporation offers the following plans:
1. Factory pre-calibrated replacement sensor/transmitter units
2. On site installation and calibration by Armstrong Monitoring
3. On site calibration by Armstrong Monitoring
4. Training by Armstrong Monitoring
Direct service enquiries to The Armstrong Monitoring Corp at [phone] or
[email protected]. The monitor should not need re-calibration when first
installed and powered up, but a test for correct operation is recommended after a stabilization
period.
The table and figure below are provided to identify key components used in calibration.
•RV4 is used to condition the signal from the sensor so that it is in a usable range. TP4
is used to monitor the signal from the sensor.
•RV5 is used to set a threshold at which the WARNING is triggered. TP5 is used to
monitor these WARNING levels.
•RV6 is used to set a threshold at which the ALARM is triggered. TP6 is used to
monitor these ALARM levels.

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Table 6: Test points and trimpots allocation
Reference Points Sensor
Signal TP4
WARNING TP5
ALARM TP6
Test Points
Ground TP7
WARNING RV5
ALARM RV6
Trimpots Span R1
TB1
TP7
RV6
R1
RV5
TP4
TP5
TP6
JB8
JB10
1
FIGURE 8: Gas Monitor 1ACO Test Points and Trimpots.
The AMC-S2e supplies a linear 1.0 to 3.3V DC signal to the monitor. This translates to a 0.4 to
1.32 volt DC signal at TP4. The alarms are set to correspond to some fraction of the
transmitters full scale calibration. The WARNING threshold is set using trimpot RV5. The
ALARM threshold is set using trimpot RV6.
5.6.1 Equipment Required
•Digital multimeter with a minimum display range of 0 to 10.0 VDC.
•Miniature screwdriver trimmer adjustment tool.
•Zero & Span gases (contact AMC for information)
5.6.2 Calibration
The AMC-S2e is delivered already calibrated from the factory. When the AMC-S2e-CO is
calibrated, it will have a 3.3V at TB1 (or 1.32V at TP4) output in the presence of 100 PPM CO
gas. The zero gas output of the AMC-S2e varies from unit to unit. This calibration procedure

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calibrates the sensor and allows alarm thresholds to be set between no gas and full range gas
levels.
Connect the negative lead of the multimeter to TP7 AGND
1) Obtain access to AMC-S2e (CO). Remove cover of 1ACO so gas can be applied
directly to the sensor and signal pot can be adjusted.
2) Attach multi-meter to measure the output signal; positive lead to TP4 and negative
lead to TP7 AGND
3) Apply the span gas sample (100ppm CO) with the calibration adapter cup firmly and
completely over the sensor for 2 minutes with flow rate 0.5 liters per minute. At 2 min
adjust the span trimpot R1 (refer to Figure 9) on the AMC-S2e(CO) for output signal
reading 3.3VDC +/- 2% (66mV)
4) In the presence of clean air (0 PPM CO), measure the output signal at TP4. Record
this value as VLOW. Use the following formula to determine what the output voltage of
the AMC-S2e(CO) will be for the gas concentration at which the alarm is to be
triggered.
VALARM = ((CALARM/ Cfull scale)*(1.32V - VLOW)) + VLOW
Where
oV
ALARM is the voltage the alarm trip point will be set to.
oC
ALARM is the gas concentration at which the alarm is to be triggered.
oC
full scale is 100 PPM for the AMC-S2e-CO.
o1.32V is level the AMC-S2e has been factory calibrated to for 100 PPM CO.
oV
LOW is the voltage measured in the previous step, representing the zero gas
output level
Adjust to appropriate alarm trimpot for the desired threshold.
•For increasing thresholds, the ALARM threshold must be higher than the WARNING
threshold.
EXAMPLE 1: To set an ALARM threshold of 50 PPM with the AMC-S2e;
•Install AMC-S2e, wait the stabilization period and measure the output signal at
TP4 and record as VLOW (use 0.380V for this example).
•C
alarm: 50 PPM
•C
full scale: 100 PPM (AMC-S2e is calibrated to this value at the factory)
•V
alarm = (( 50 PPM / 100 PPM) * (1.320V – 0.380V)) + 0.380V
= 0.850V
RV6 would be adjusted so that 0.850V is measured at TP6.
EXAMPLE 2: To set a WARNING threshold of 25 PPM with the AMC-S2e;
•Install AMC-S2e, wait the stabilization period and measure the output signal at
TP4 and record as VLOW (use 0.380V for this example).
•C
alarm: 25 PPM
•C
full scale: 100 PPM (AMC-S2e is calibrated to this value at the factory)

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•V
alarm = (( 25 PPM / 100 PPM) * (1.320V – 0.380V)) + 0.380V
= 0.615V
RV5 would be adjusted so that 0.615V is measured at TP5.
+
-
MULTIMETER
DIGITAL
MEASURE VOLTAGE
AT SIG. TEST PT.
WITH RED (+) LEAD
CONNECT BLACK
( - ) LEAD TO GND.
PAD
TB1
TP7
RV6
RV4
RV5
TP1
TP2
TP3
TP4
TP5
TP6
JB8
JB10
1
R1
Figure 9: Trimmer adjustment and test point locations