Critical Environment Technologies GEM-II User manual

Operation Manual
www.critical-environment.com
GEM-IISelf Contained Gas Detector
Rev. E | 2014.10

2 © 2014 All rights reserved. Data subject to change without notice.
GEM-II - Operation Manual Rev. E | 2014.10
TABLE OF CONTENTS
1 POLICIES.................................................................................................................. 5
1.1 Important Note..............................................................................................................5
1.2Warranty Policy..............................................................................................................6
1.3 Service Policy.................................................................................................................6
1.4 Copyrights......................................................................................................................7
1.5 Disclaimer......................................................................................................................7
1.6 Revisions........................................................................................................................8
2 INTRODUCTION ..................................................................................................... 9
2.1 General Description .......................................................................................................9
2.2 Key Features...................................................................................................................9
2.3 Model Designations.....................................................................................................10
2.3.1Type A – Single Channel ............................................................................................... 10
2.3.2Type B – Single Channel Controller............................................................................... 11
2.3.3Type D – Dual Channel.................................................................................................. 12
2.3.4Type E– Dual Channel................................................................................................... 13
3 INSTRUMENT SPECIFICATIONS .........................................................................13
3.1Technical Specications................................................................................................13
3.2 Standard Enclosure Dimensions...................................................................................16
3.3Watertight Enclosure Dimensions ................................................................................16
4 SENSOR SPECIFICATIONS...................................................................................17
4.1 Sensor Specications ...................................................................................................17
4.2 Remote Sensor Specications......................................................................................18
4.3 Calibration Extending Firmware (CEF) and Sensor Aging .............................................18
5 FEATURES & FUNCTIONS....................................................................................19
5.1 Standard Exterior Enclosure.........................................................................................19
5.2Watertight Exterior Enclosure ......................................................................................20
5.3 Interior System Layout.................................................................................................21
6 INSTALLATION......................................................................................................22
6.1 AC and DC Wiring .........................................................................................................22
6.1.1Wiring Example 1.......................................................................................................... 22
6.1.2Wiring Example 2.......................................................................................................... 23

© 2014 All rights reserved. Data subject to change without notice. 3
Rev. E | 2014.10 GEM-II - Operation Manual
6.1.3Wiring Example 3 - INCORRECT ..................................................................................... 23
6.1.4Wiring Example 4.......................................................................................................... 24
6.1.5Wiring Example 5 (J2 Removed) ................................................................................... 24
6.1.6Wiring Example 6 (J2 Removed) ................................................................................... 25
6.2 Sensor Mounting Heights ............................................................................................25
6.3 Standard Enclosure Mounting Components.................................................................26
6.3.1 Enclosure Base.............................................................................................................. 26
6.3.2 EnclosureTop................................................................................................................ 26
6.3.3 Enclosure Bottom ......................................................................................................... 27
6.4 Remote Sensor Connection..........................................................................................27
6.5Wiring Connections......................................................................................................28
6.5.1Types A, B and D............................................................................................................ 28
6.5.2Type E............................................................................................................................ 28
6.6 Important Notes for Wiring..........................................................................................29
6.7 System Installation......................................................................................................29
6.7.1 Low Voltage Power ........................................................................................................29
6.7.2Wiring to Remote Sensor .............................................................................................. 30
6.7.3Voltage to Remote Sensors ........................................................................................... 30
6.7.4 Relay Connections......................................................................................................... 30
6.8 Installation Examples...................................................................................................31
6.8.1Type A with Internal Sensor and Enclosed Transformer ................................................. 31
6.8.2Type B with Remote Sensor or AnalogTransmitter........................................................ 32
6.8.3Type D with One Internal & One Remote Sensor............................................................ 33
6.8.4Type E withTwo Internal Sensors .................................................................................. 34
7 OPERATION...........................................................................................................34
7.1 System Operation ........................................................................................................34
7.2 Test Functions ..............................................................................................................35
7.3 Dip Switch Package......................................................................................................36
7.4 Internal Audible Alarm Operation................................................................................37
7.5 Jumpers.......................................................................................................................37
7.6 Adjusting Alarm Set Points ..........................................................................................39
7.6.1Voltage ReferenceTable for Alarm Settings................................................................... 41
7.7Time Delays for Relay Operations.................................................................................42
7.7.1 Procedure for SettingTime Delays .................................................................................44
7.8Temperature Display - Unit of Measure ........................................................................45

4 © 2014 All rights reserved. Data subject to change without notice.
GEM-II - Operation Manual Rev. E | 2014.10
7.9 Latching Relay Functions .............................................................................................45
7.10 LED Digital Display.....................................................................................................46
8 CALIBRATION........................................................................................................47
8.1 Calibration Specications.............................................................................................47
8.1.1 Gas................................................................................................................................ 47
8.1.2 Exception...................................................................................................................... 47
8.1.3 Regulators & Flow......................................................................................................... 47
8.1.4 Adapters....................................................................................................................... 47
8.2 Calibrating Sensors ......................................................................................................48
8.2.1 Calibration Frequency................................................................................................... 48
8.3 Calibration Procedure...................................................................................................48
8.4 Calibrating the Internal Sensor ....................................................................................49
8.4.1 Setting Span Gas Value................................................................................................. 49
8.4.2 Calibrating the Null (Zero)Value................................................................................... 49
8.4.3 Calibrating the Span Gas............................................................................................... 50
8.5 Calibrating Second Internal Sensor ..............................................................................51
8.6 Calibrating Remote Sensor..........................................................................................51
8.6.1 Setting Span Gas Value for Remote Sensor ................................................................... 51
8.6.2 Calibrating the Null (Zero)Value................................................................................... 51
8.6.3 Calibrating the Span Gas............................................................................................... 52
8.7 Calibrating 4-20 mA for Incoming AnalogTransmitter................................................53
8.7.1 Using a Current Source to Calibrate the Null.................................................................. 53
8.7.2 Using a Current Source to Calibrate the Span ................................................................ 53
8.7.3 Using a CETCI Analog Transmitter to Calibrate the Null.................................................. 54
8.7.4 Using a CETCI Analog Transmitter to Calibrate the Span................................................ 54
8.8 Forcing Calibration......................................................................................................55
9 ACCESSORIES .......................................................................................................56
9.1 Calibration Kit..............................................................................................................56
9.2 Metal Protective Guard ................................................................................................56
10 MAINTENANCE ..................................................................................................57

© 2014 All rights reserved. Data subject to change without notice. 5
Rev. E | 2014.10 GEM-II - Operation Manual
1 POLICIES
1.1 Important Note
Read and understand this manual prior to using this instrument. Carefully read the warranty
policy, service policy, notices, disclaimers and revisions on the following pages.
This product must be installed by a qualied electrician or factory trained technician and
according to instructions indicated in this manual. This instrument should be inspected and
calibrated regularly by a qualied and trained technician. For more information, refer to Sections
8 Calibration and 10 Maintenance of this manual.
This instrument has not been designed to be intrinsically safe. For your safety, do not use it in
classied hazardous areas (explosion-rated environments).
INSTRUMENT SERIAL NUMBER:
__________________________________________________________
PURCHASE DATE:
__________________________________________________________
PURCHASED FROM:
__________________________________________________________

6 © 2014 All rights reserved. Data subject to change without notice.
GEM-II - Operation Manual Rev. E | 2014.10
1.2 Warranty Policy
• Disconnect power before servicing
• Caution: More than one live circuit
• Supply: 24 V (nominal, 50 or 60 Hz)
• Certied for electrical shock and electrical re hazard only
Critical EnvironmentTechnologies Canada Inc. (CETCI), also referred to as the manufacturer,
warrants this instrument, (excluding sensors, battery packs, batteries, pumps and lters) to be
free from defects in materials and workmanship for a period of two years from the date of
purchase from our facility. The sensors have a warranty period of one year on a pro-rated
basis from the date of purchase from our facility. If the product should become defective
within this warranty period, we will repair or replace it at our discretion.
The warranty status may be aected if the instrument has not been used and maintained per
the instructions in this manual or has been abused, damaged, or modied in any way.This
instrument is only to be used for purposes stated herein.The manufacturer is not liable for
auxiliary interfaced equipment or consequential damage.
Due to ongoing research, development, and product testing, the manufacturer reserves the
right to change specications without notice.The information contained herein is based on data
considered accurate. However, no warranty is expressed or implied regarding the accuracy of this
data.
All goods must be shipped to the manufacturer by prepaid freight. All returned goods must be
pre-authorized by obtaining a Returned Merchandise Authorization (RMA) number. Contact the
manufacturer for a number and procedures required for product transport.
1.3 Service Policy
CETCI maintains an instrument service facility at the factory. Some CETCI distributors / agents
may also have repair facilities; however, CETCI assumes no liability for service performed by
anyone other than CETCI personnel.
Repairs are warranted for 90 days after date of shipment (sensors have individual warranties).
Should your instrument require non-warranty repair, you may contact the distributor from
whom it was purchased or you may contact CETCI directly.

© 2014 All rights reserved. Data subject to change without notice. 7
Rev. E | 2014.10 GEM-II - Operation Manual
Prior to shipping equipment to CETCI, contact our oce for an RMA #. All returned goods must
be accompanied with an RMA number.
If CETCI is to do the repair work, you may send the instrument, prepaid, to:
Attention: Service Department
Critical Environment Technologies Canada Inc.
Unit 145, 7391 Vantage Way
Delta, BC, V4G 1M3
Always include your Returned Merchandise Authorization (RMA) number, address, telephone
number, contact name, shipping / billing information, and a description of the defect as
you perceive it.You will be contacted with a cost estimate for expected repairs, prior to the
performance of any service work.
For liability reasons, CETCI has a policy of performing all needed repairs to restore the instrument
to full operating condition.
Pack the equipment well (in its original packing if possible), as we cannot be held responsible for
any damage incurred during shipping to our facility.
1.4 Copyrights
This manual is subject to copyright protection; all rights are reserved. Under international and
domestic copyright laws, this manual may not be copied or translated, in whole or in part, in any
manner or format, without the written permission of CETCI.
1.5 Disclaimer
Under no circumstances will CETCI be liable for any claims, losses or damages resulting from or
arising out of the repair or modication of this equipment by a party other than CETCI service
technicians, or by operation or use of the equipment other than in accordance with the printed
instructions contained within this manual or if the equipment has been improperly maintained
or subjected to neglect or accident. Any of the foregoing will void the warranty.
Under most local electrical codes, low voltage wires cannot be run within the same conduit as
line voltage wires. It is CETCI policy that all wiring of our products meet this requirement.
It is CETCI policy that all wiring be within properly grounded (earth or safety) conduit.

8 © 2014 All rights reserved. Data subject to change without notice.
GEM-II - Operation Manual Rev. E | 2014.10
1.6 Revisions
This manual was written and published by CETCI. The manufacturer makes no warranty or
representation, expressed or implied including any warranty of merchantability or tness for
purpose, with respect to this manual.
All information contained in this manual is believed to be true and accurate at the time
of printing. However, as part of its continuing eorts to improve its products and their
documentation, the manufacturer reserves the right to make changes at any time without
notice. Revised copies of this manual can be obtained by contacting CETCI or visiting
www.critical-environment.com.
Should you detect any error or omission in this manual, please contact CETCI at the following
address:
Critical Environment Technologies Canada Inc.
Unit 145, 7391Vantage Way, Delta, BC, V4G 1M3, Canada
Toll Free: +1.877.940.8741
Telephone: [phone]
Fax: [phone]
Email: mark[email protected]
Website: www.critical-environment.com
In no event will CETCI, its ocers or employees be liable for any direct, special, incidental
or consequential damages resulting from any defect in any manual, even if advised of the
possibility of such damages.

© 2014 All rights reserved. Data subject to change without notice. 9
Rev. E | 2014.10 GEM-II - Operation Manual
2 INTRODUCTION
2.1 General Description
Thank you for purchasing our GEM-II self-contained gas detector.
The GEM series gas detection systems are economical, self-contained, gas detectors for non-
hazardous (non-explosion rated) commercial applications.They are available in two basic
congurations: one sensor models and two sensor models. The sensors can be congured as one
integral (A-type), one remote (B-type), one integral and one remote (D-type), or two integral
(E-type).
A basic system provides one set of LED indicating lights representing“Power”,“Fail”,“Low
(Warning) Gas Alarm”,‘High Gas Alarm”, an integral audible alarm with door mounted silence
push-button, audible time delay, eld settable relay time delays and two alarm relays. In either
system, the LED lights provide visual indication of the status of each channel (Int = internal
sensor, Ext = external sensor or second channel).
Gas specic electrochemical sensors for toxic gases and Oxygen (O2) are available as are MOS
solid-state sensors for refrigerants and catalytic sensors for combustible gases. All GEM integral
sensors are packaged as plug-in“smart”sensor modules to reduce eld maintenance time.
If after reading through the manual, you have any questions, please do not hesitate to contact
our service department for technical support.
2.2 Key Features
• Single or dual channel
• Network multiple units
• Integral plug & play“smart”sensors or remote sensors
• 4 – 20 mA linear output signal
• Three conduit entry ports
• Thermal resetting fuse
• LED light indicators
• Two 5-amps SPDT relays
• RoHS compliant circuit boards
• CSA & UL certied

10 © 2014 All rights reserved. Data subject to change without notice.
GEM-II - Operation Manual Rev. E | 2014.10
2.3 Model Designations
2.3.1 Type A – Single Channel
Choices for GEM-A:
• One integral electrochemical sensor.
NOTES: Optional LED digital display is shown in the photo.
Opening for integral sensor
(example: CO) to monitor
diused air and gas.

© 2014 All rights reserved. Data subject to change without notice. 11
Rev. E | 2014.10 GEM-II - Operation Manual
2.3.2 Type B – Single Channel Controller
Choices for GEM-B:
• One remote catalytic or solid state sensor
• One remote LPT-A or LPT series analog transmitter
NOTES: Optional LED digital display is shown in the photo.
Wiring requirements:
• 3-conductor, 18 gauge to remote sensor.
• 3-conductor shielded to remote analog transmitter.
Plug covering
sensor opening
Remote catalytic or
solid state sensor
Remote analog transmitterOR

12 © 2014 All rights reserved. Data subject to change without notice.
GEM-II - Operation Manual Rev. E | 2014.10
2.3.3 Type D – Dual Channel
Choices for GEM-D:
• One integral electrochemical sensor (Channel1) PLUS one remote catalytic or solid state
sensor (Channel 2).
• One integral electrochemical sensor (Channel1) PLUS one remote LPT-A or LPT series
analog transmitter (Channel 2).
NOTES: Optional LED digital display is shown in the photo.
Wiring requirements:
• 3-conductor, 18 gauge to remote sensor.
• 3-conductor shielded to remote analog transmitter.
Opening for
integral sensor
to monitor
diused by air
and gas.
Remote catalytic or
solid state sensor
Remote analog transmitterOR

© 2014 All rights reserved. Data subject to change without notice. 13
Rev. E | 2014.10 GEM-II - Operation Manual
2.3.4 Type E – Dual Channel
Choices for GEM-E:
• Two integral electrochemical sensors (Channel 1 & 2)
NOTES: Optional LED digital display is shown in the photo.
3 INSTRUMENT SPECIFICATIONS
3.1 Technical Specications
GAS TYPE
Carbon Monoxide (CO)
Combustible Gases (catalytic)
Hydrogen (H2), Methane (CH4), Propane (C3H8)
Nitrogen Dioxide (NO2)
Nitric Oxide (NO)
Oxygen (O2)
Refrigerants (solid state)
R22, R134A, R402A, R404A, R407C, R410A, R422A, R422D, R507A
Sulphur Dioxide (SO2)
TVOCs (solid state)
Opening for TWO integral
sensors to monitor diused
air and gas.
Common application is
engine exhaust: gasoline
or diesel sensors are both
integral in the GEM type E
version.

14 © 2014 All rights reserved. Data subject to change without notice.
GEM-II - Operation Manual Rev. E | 2014.10
MECHANICAL
Standard Enclosure General purpose PVC
Standard Weight 600 g (1.2 lb)
Standard Size 5.3”x 6.8”x 2.6”(135 mm x 173 mm x 66 mm)
Watertight Enclosure Water / dust tight polycarbonate
WatertightWeight 700 g (1.4 lb)
Watertight Size 5.1”x 7.1”x 4.0”(130 mm x 181 mm x 102 mm)
ELECTRICAL
Power Requirement 15 - 30VDC or 12 - 28VAC
Current Draw Approximately 125 mA
Wiring VDC three-conductor shielded
VAC four-conductor shielded
Circuit Analog design with microprocessor and user settable time
delays, accessible with DIP switches on circuit board.
Fuse Automatic resetting thermal
INPUT / OUTPUT
Outputs Linear 4 - 20 mA (single)
Distance Maximum 500 ft between controller and remote solid state
sensor using minimum 18 gauge wire.
Relays
Two S.P.D.T. dry contact relays, rated 5 amps @ 240 VAC.
NOTES:
1. System is congured such that all relays are“FAIL SAFE”
(relay coils are always energized in non-alarm state).
2. Relays are“common”to both channels (activated by either
channel).
USER INTERFACE
Display Common set of LED indicating lights for“Power”,“Fail”,“Low
(Warning) Gas Alarm”,“High Gas Alarm”

© 2014 All rights reserved. Data subject to change without notice. 15
Rev. E | 2014.10 GEM-II - Operation Manual
Audible
Integral piezo audible alarm rated 80 dB @ 10’ c/w door mounted
silence push-button.
NOTES: Audible alarm & silence push-button are right side
mounted on water tight enclosure.
Time Delays
Delay“ON”(on make),
DIP switch
Delay“OFF”(on break),
DIP switch
Audible (on make),
DIP switch
Low alarm relay: 2 minutes
High alarm relay: 5 minutes
Also known as“minimum run time”
Low alarm relay: 10 minutes
High alarm relay: not available
10 minutes
NOTES: Time delays can be changed by user.
Reference Section 7 Operation. DIP switches are still used to
enable or disable time delays.
SENSOR
Enclosure Molded PVC
Integral
Electrochemical only
NOTES: All integral electrochemical gas sensors are packaged as
“smart”sensor modules.
Remote
Solid State sensor for refrigerants andTVOCs
Catalytic sensor for combustible gases
Analog transmitter, LPT-A or LPT (4 – 20 mA signal)
ENVIRONMENTAL (sensor dependant)
OperatingTemperature -20°C to 50°C (-5°F to 120°F)
Operating Humidity 15 - 90% RH non-condensing

16 © 2014 All rights reserved. Data subject to change without notice.
GEM-II - Operation Manual Rev. E | 2014.10
CERTIFICATION
CSA Certied
UL Certied
3.2 Standard Enclosure Dimensions
3.3 Watertight Enclosure Dimensions
5.25”(133 mm)
2.625”(67 mm) 6.75”(172 mm)
5.13”(130 mm)
7.13”(181 mm)4.0”(102 mm)
4.38”(102 mm)

© 2014 All rights reserved. Data subject to change without notice. 17
Rev. E | 2014.10 GEM-II - Operation Manual
4 SENSOR SPECIFICATIONS
4.1 Common Sensor Specications
Carbon Monoxide (CO)
Type Electrochemical
ResponseTime <30 seconds to 90% of signal response
OperatingTemperature 0°C to 50°C (32°F to 120°F)
Repeatability ± 10% of set point
Life Span 3 years in air (under normal conditions)
Nitric Oxide (NO)
Type Electrochemical
ResponseTime <30 seconds to 90% of signal response
OperatingTemperature 0°C to 50°C (32°F to 120°F)
Repeatability ± 10% of set point
Life Span 2 years in air (under normal conditions)
Nitrogen Dioxide (NO2)
Type Electrochemical
ResponseTime <30 seconds to 90% of signal response
OperatingTemperature 0°C to 50°C (32°F to 120°F)
Repeatability ± 10% of set point
Life Span 3 years in air (under normal conditions)
Sulphur Dioxide (SO2)
Type Electrochemical
ResponseTime <30 seconds to 90% of signal response
OperatingTemperature 0°C to 50°C (32°F to 120°F)
Repeatability ± 10% of set point
Life Span 2+ years in air (under normal conditions)

18 © 2014 All rights reserved. Data subject to change without notice.
GEM-II - Operation Manual Rev. E | 2014.10
Temperature (°C or °F)
Range -20°C to 40°C (-4°F to 104°F)
4.2 Remote Sensor Specications
1. Remote sensor module: The remote sensor housing accommodates one catalytic or one solid-
state sensor. 2. Any 4-20 mA analog transmitters manufactured by CETCI (LPT-A or LPT series).
Combustible Gases
Type Catalytic
ResponseTime <10 seconds to 90% of signal response
OperatingTemperature -10°C to 50°C (14°F to 122°F)
Repeatability ± 10% of set point
Life Span 5 years in air (under normal conditions)
Typical Gas Examples Hydrogen (H2), Propane (C3H8), Methane (CH4)
Refrigerants
Type Solid state
ResponseTime <120 seconds to 90% of signal response
OperatingTemperature 0°C to 40°C (32°F to 104°F)
LongTerm Drift < 5% signal loss / month at ambient temperatures
Repeatability ± 10% of set point
Life Span 5 years in air (under normal conditions)
Typical Gas Examples R11, R12, R22, R134A, R404A, R407C, R410A, R422A, R422D,
R438A, R507A
4.3 Calibration Extending Firmware (CEF) and Sensor Aging
GEM systems with integral electrochemical sensors have been programmed with our CEF
(Calibration Extending Firmware).This rmware takes into consideration the aging of the
electrochemical CO, NO and NO2sensors so that less frequent calibrations are acceptable in
non-critical applications such as parking garages.The system tracks the age of the sensor and
automatically compensates for the degraded output of the sensor as it ages.

© 2014 All rights reserved. Data subject to change without notice. 19
Rev. E | 2014.10 GEM-II - Operation Manual
5 FEATURES & FUNCTIONS
5.1 Standard Exterior Enclosure
NUMBER FEATURE FUNCTION
➊Digital Display Optional LED digital display
➋LED Sensor Indicators Indicates Channel 1 or Channel 2
➌Door Latch Secures door
➍LED Indicators Indicates Power & Fail
➎Door Screw Secures door
➏Gas Alarm LED Indicates High and Low alarm levels
➐Alarm Acknowledge-Test Push button for alarm acknowledgement &
testing
➑Audible Alarm Internal audible alarm
➒Sensor Opening To monitor diused air and gas
➓Padlock Opening For padlock









20 © 2014 All rights reserved. Data subject to change without notice.
GEM-II - Operation Manual Rev. E | 2014.10
5.2 Watertight Exterior Enclosure
NUMBER FEATURE FUNCTION
➊Digital Display Optional LED digital display
➋LED Sensor Indicators Indicates Channel 1 or Channel 2
➌Audible Alarm Watertight audible alarm & silence push
button
➍LED Indicators Indicates Power & Fail
➎Gas Alarm LED Indicates High and Low alarm levels
➏Silence Button Watertight silence push button
➐Splash Guard Optional splash guard secured with
stainless steels screws
NOTE: Audible alarm and silence push button were moved to right of enclosure to maintain
water tightness of enclosure.





