Bacharach GDC-150 User manual

Instruction 5209-9000
Operation Manual
Rev. 0 - May 2011
Product Leadership •Training •Service •Reliability

GDC-150 Operation Manual
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IMPORTANT NOTE
READ AND UNDERSTAND THIS MANUAL PRIOR TO USING THIS INSTRUMENT.
THIS INSTRUMENT SHOULD BE INSPECTED AND PROGRAMMED BY
QUALIFIED AND TRAINED PERSONNEL.
THIS INSTRUMENT HAS NOT BEEN DESIGNED TO BE INTRINSICALLY SAFE IN
HAZARDOUS OR EXPLOSION-RATED ENVIRONMENTS. FOR YOUR SAFETY,
DO NOT USE OR INSTALL IT IN AREAS CLASSIFIED AS HAZARDOUS AREAS
(E.G., EXPLOSION-RATED ENVIRONMENTS).

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DISCLAIMER
UNDER NO CIRCUMSTANCES WILL BACHARACH, INC. BE LIABLE FOR ANY
CLAIMS, LOSSES OR DAMAGES RESULTING FROM OR ARISING OUT OF THE
REPAIR OR MODIFICATION OF THIS EQUIPMENT BY A PARTY OTHER THAN
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OPERATION OR USE OF THE EQUIPMENT OTHER THAN IN ACCORDANCE
WITH THE PRINTED INSTRUCTIONS CONTAINED WITHIN THIS MANUAL OR IF
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BACHARACH, INC. WARRANTS THIS INSTRUMENT TO BE FREE FROM
DEFECTS IN MATERIALS AND WORKMANSHIP FOR A PERIOD OF TWO (2)
YEARS FROM THE DATE OF PURCHASE. THIS INCLUDES ALL ELECTRONICS,
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CARBON MONOXIDE (CO) SENSORS. OTHER ELECTROCHEMICAL SENSORS
ARE WARRANTED FOR ONE YEAR.
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OR IMPLIED REGARDING THE ACCURACY OF THIS DATA.
ALL GOODS MUST BE SHIPPED TO THE MANUFACTURER BY PREPAID
FREIGHT. ALL RETURNED GOODS MUST BE ACCOMPANIED BY AN RMA
NUMBER.

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SERVICE POLICY
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621 HUNT VALLEY CIRCLE
NEW KENSINGTON, PA 15068
ATTENTION: SERVICE DEPARTMENT
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GDC-150 Operation Manual
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REVISIONS
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OR FITNESS 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, BACHARACH RESERVES
THE RIGHT TO MAKE CHANGES AT ANY TIME WITHOUT NOTICE. REVISED
COPIES OF THIS MANUAL CAN BE OBTAINED BY CONTACTING BACHARACH,
INC.
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PLEASE CONTACT THE COMPANY AT THE FOLLOWING ADDRESS.
BACHARACH, INC.
621 HUNT VALLEY CIRCLE
NEW KENSINGTON, PA 15068-7074
USA
TOLL FREE: 1-800-736-4666
FAX: [phone]
E-MAIL: [e-mail]
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LIABLE FOR ANY DIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL
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OF THE POSSIBILITY OF SUCH DAMAGES.

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TABLE OF CONTENTS
1. OVERVIEW................................................................................................................1
1.1. General Description............................................................................................ 1
1.2. Enclosures.......................................................................................................... 1
1.3. Key Components................................................................................................ 3
2. SPECIFICATIONS .....................................................................................................4
2.1. General............................................................................................................... 4
2.2. Standard Enclosures .......................................................................................... 4
2.3. Optional Enclosures............................................................................................ 4
2.4. Sensors (Solid-State and Catalytic) .................................................................... 5
2.5. Sensors (Electrochemical).................................................................................. 6
2.6. Sensor Cross Sensitivity (Electrochemical)......................................................... 7
3. INSTALLATION .........................................................................................................8
3.1. Mounting Holes and Conduit Ports...................................................................... 8
3.2. Enclosure Door................................................................................................... 9
3.3. Sensor Mounting Height Recommendations......................................................10
3.4. Wiring the GDC-150 for Power ..........................................................................10
4. OPERATION............................................................................................................13
4.1. General..............................................................................................................13
4.2. Detecting Gas....................................................................................................14
4.3. System Failure...................................................................................................14
4.4. Sensor Notes.....................................................................................................14
4.5. Open Loop Diagnostic .......................................................................................15
4.6. Jumper Functions...............................................................................................15
4.7. Adjusting the Alarm Set Point (For Relay Option Only) ......................................15
4.7.1. Calculating the Alarm Set Point Value....................................................15
4.7.2. Adjusting the Alarm Set Point................................................................. 16
5. CALIBRATION......................................................................................................... 16
5.1. Frequency Recommendations...........................................................................16
5.2. Calibration Specifications – Gases.....................................................................17
5.3. Regulators and Flow – Solid-State and Catalytic Sensors..................................17
5.4. Regulators and Flow – Electrochemical Sensors ...............................................17
5.5. Calculating the Span Gas Value ........................................................................18
5.6. Setting the Span Gas Value...............................................................................19
5.7. Calibrating the Null (Zero) Value........................................................................19
5.8. Calibrating the Span Value ................................................................................20
6. ACCESSORIES AND REPLACEMENT PARTS...................................................... 21
6.1. Metal Protective Guards ....................................................................................21
6.2. Accessory and Replacement Part Numbers.......................................................21

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1. OVERVIEW
1.1. General Description
GDC-150 transmitters are rugged, user-friendly, configurable analog transmitter gas
detectors for use in non-hazardous (non-explosion rated) environments for
commercial HVAC and light industrial use. It can be configured for either
electrochemical toxic gas sensors, solid-state sensors, or catalytic sensors.
A standard transmitter provides a bi-color LED indicating light for power, fault
condition, and alarm (option with one dry contact relay). An optional LED digital
display is available as well as other enclosure options.
The electrochemical sensors utilized in this device are accurate enough to measure to
Occupational Health and Safety hazardous levels for toxic gases and oxygen levels.
NOTE: The GDC-150 analog transmitters operate by diffusion. If a
sample draw system is desired, consult a Bacharach authorized
distributor or the factory for details.
1.2. Enclosures
Figure 1-1. Standard (NEMA 1X) Enclosures

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Figure 1-2. Optional Water-Tight (NEMA 4X) Enclosure
Figure 1-3. Water-Tight Enclosure (Side View) Showing Optional Splash Guard
NOTE: GDC-
150 transmitters utilizing catalytic combustible or
electrochemical H2S/SO2sensors are supplied with the water- and dust-
tight NEMA 4X enclosure standard.

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1.3. Key Components
Figure 1-4. Key Components on GDC-150 Circuit Board

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2. SPECIFICATIONS
2.1. General
All Sensor Types
Power 12 VAC to 30 VAC or 16 VDC to 30 VDC1
Current 80 to 120 mA2
Indicators
One bi-color LED:
•Green = Power •Red = Alarm
•
Flash Green = Warm-up
•
Flash Red = Fail
One amber LED (internal relay coil status indicator) 3
One red LED (4-20 mA open-loop indicator for remote transmitter)
Options
•LED digital display (3.5 digits)
•Relay (one SPDT dry contact relay rated 2A @ 30 VAC)
•Water/dust tight enclosure
•Splash guard (water-tight enclosure only)
2.2. Standard Enclosures
Solid-State Catalytic Electrochemical
Type PVC Polycarbonate PVC
Dims
(HxWxD) 6.5 x 4.4 x 2.5 in
165 x113 x 65 mm 4.9 x 4.9 x 2.9 in 125 x125 x 75 mm 6.5 x 4.4 x 2.5 in 165 x113 x 65 mm
Weight 20 ounces 16 ounces 20 ounces
Construction Drip-proof overlap
with hinged door Water- & dust-tight with hinged door Drip proof overlap with hinged door
2.3. Optional Enclosures
Solid-State Catalytic Electrochemical
Type Polycarbonate Polycarbonate
Dims
(HxWxD) 4.9 x 4.9 x 2.9 in
125 x125 x 75 mm 4.9 x 4.9 x 2.9 in 125 x125 x 75 mm
Weight 16 ounces 16 ounces
Construction Water- & dust-tight
with hinged door Water- & dust-tight with hinged door
1Non ground referenced supply only
2For electro-chemical sensors, this depends on the options that are selected.
3Only supplied if relay option has been selected

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2.4. Sensors (Solid-State and Catalytic)
Solid-State Catalytic
Type Solid-state MOS4Catalytic pellistor
Range Combustible: 0-50% LEL
Refrigerant: 0-2000 ppm 0-100% LEL of target
combustible gas or vapor
Life Span
Combustible: Approximately 5
to 8 years in clean, ambient
conditions
Refrigerant: Approximately 5+
years in clean, ambient
conditions
Approximately 5 years in clean,
ambient conditions
Resolution Combustible: 1% LEL
Refrigerant: 2 ppm 1% LEL
Temperature -20°C to +40°C
(-4°F to +104°F) -20°C to +40°C (-4°F to +104°F)
Humidity 0-90% non-condensing 0-90% non-condensing
Response Combustible: T90 = <60 seconds
Refrigerant: T90 = <120 seconds
for most refrigerants
T90 from air to 50% LEL = <12
seconds
Warm-up 2 minute delay
24 hours for best performance
(maximum accuracy)
2 minute delay
1 hour for best performance
(maximum accuracy)
4MOS: Metal Oxide Semiconductor

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2.5. Sensors (Electrochemical)
Sensor Range
Life
Span
5
Reso-
lution
Temp RH6
Response
Time (T90)
Warm
Up
Ammonia (NH3)0-500
ppm 21-2 ppm
-40 TO
+50°C
715-90%
<90 sec 2-6
hrs
Carbon Monoxide
(CO) 0-200 ppm 5-8
1
ppm,
3
ppm
8
-20 to
+50°C
10-95% <2 min 1 hr9
Hydrogen Sulfide
(H2S)
0-50
ppm
3
0.5
ppm
-30 to
+50°C
15-90%
<35 sec
(0-20 ppm)
1 hr9
Nitrogen Dioxide
(NO2)
0-5.0
ppm 3
0.1
ppm
-30 to
+50°C 15-90%
<60 sec
(0-10 ppm)
1-2
hrs
Nitric Oxide (NO) 0-100
ppm
31 ppm -30 to
+50°C
15-90% <20 sec
(0-50 ppm)
1-2
hrs
Oxygen (O2)
0-25.0
% vol
2
0.1%
vol
-30 to
+50°C
5-95%
<15 sec
(20.9%-0%)
1 hr9
Sulfur Dioxide
(SO2)
0-20
ppm
21 ppm
-30 to
+50°C
15-90%
<30 sec
(0-20 ppm)
2 hrs
Formaldehyde
(HCHO)
0-10
ppm 2
0.2
ppm
-20 to
+50°C 15-90% <80 sec 1 hr
5Approximate, in years
6Non-condensing
7Temperature drift occurs
8Without regular calibration
9Minimum warm-up time

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2.6. Sensor Cross Sensitivity (Electrochemical)
Sensor Cross Sensitivity – Electrochemical Sensors Only
Ammonia
0-500 ppm 300 ppm CO = 8 10% vol CO2 = -15 35 ppm NO = 6
15 ppm H2S = 30 1 ppm Cl2 = -1 5 ppm HCl = -3
5 ppm SO2 = -0.5 200 ppm H2 = 4 5 ppm NO2 = -1
Carbon
Monoxide Conforms to UL 2034 performance specification.
Hydrogen
Sulfide 20 ppm SO2≤18 50 ppm NO ≤ 6 10 ppm NO2≤ -30
10 ppm Cl2 ≤ -25 400 ppm H2 ≤ 1 400 ppm C2H4 ≤ 0.8
400 ppm CO ≤ 4 400 ppm NH3 ≤ 0.1
Nitrogen
Dioxide 50 ppm NO ≤ 0.5 20 ppm SO2 ≤ -2 10 PPM Cl2 = 100
400 ppm H2 ≤ 0.1 20 ppm H2S = -100 400 ppm CO ≤ 0.1
400 ppm C2H4 ≤ 0.1 20 ppm NH3 ≤ 0.1
Nitric Oxide 10 ppm NO2 ≤ 5 20 ppm SO2 ≤ 4 10 ppm Cl2 ≤ 5
400 ppm H2 ≤ 0.1 20 ppm H2S ≤ 60 400 ppm CO ≤ 0.1
20 ppm NH3 ≤ 0.1
Oxygen 5% volume CO2 = 0.1 0% to 95% RH @ 40°C ≤ 0.7
Sulfur Dioxide 50 ppm NO ≤ -3 10 ppm NO2 ≤ -100 10 ppm Cl2 ≤ -70
400 ppm H2 ≤ 0.1 400 ppm CO ≤ 1 400 ppm C2H4 ≤ 40
20 ppm NH3 ≤ 0.1
Formaldehyde
(HCHO) 100 ppm CO <18 100 ppm H2 ≤ 3
Other reducing gases such as alcohol (Note: Formalin –
commercial grade formaldehyde – contains alcohol.)

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3. INSTALLATION
3.1. Mounting Holes and Conduit Ports
The GDC-150 should be installed on a flat vertical surface with the sensor pointing
outwards in a clean, dry environment. If the GDC-150 is to be installed in a potentially
wet environment, the optional water-tight enclosure should have been selected. This
reference refers to the standard, general purpose PVC enclosure. Four mounting
holes are provided in the enclosure base for securing the GDC-150 to the wall. Do
not block the front of the enclosure as this is where the sensor is situated and where it
monitors the air for the target gas.
NOTE: Four mounting holes are provided in the enclosure base for
securing the GDC-150 to the wall. The mounting holes are 3/16″ (4.8
mm) in diameter.
Conduit entry points are provided for the PVC enclosure.
Figure 3-1. Standard Enclosure Showing Mounting Holes
The water-tight enclosure must be installed with the mounting screws passing through
the same openings that accommodate the four door securing screws. This ensures
the mounting screws are outside of the door gasket and confirms a water-tight
installation.
NOTE: No conduit entry points are provided for the water-tight
enclosure. The reason is the installer may not want one where we
would place it and this would result in unnecessary openings into this
enclosure.

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Figure 3-2. Water-Tight Enclosure Showing Mounting Holes
WARNING: Do not drill holes in the back of the base of the enclosure
for the purpose of mounting the sensor/transmitter. Leak paths can
occur. Corrosion damage will not be covered under warranty.
NOTE: Use caution when drilling holes in the water-tight enclosure for
conduit entry so as not to damage the circuit board inside. Use liquid
tight conduit hubs wherever conduit enters the water-tight enclosure.
Failure to do so creates a leak path. Water running down the conduit
enters the interior of the enclosure and could corrode the circuit board.
This is not covered under warranty.
NOTE: When mounting either enclosure, allow enough room to enable
the end user to open the door fully to access the internal adjustments.
3.2. Enclosure Door
The standard enclosure has one screw securing the door to the base for electrical
safety and provides an opening to allow the user to apply a zip tie if they desire the
transmitter to be locked more securely. Refer to Figure 1-1 on page 1.
The door of the standard enclosure can be easily removed to facilitate installation of
the base. Simply grasp the lid with one hand, being careful not to make contact with
any of the internal components (circuit board), and grasp the base with your other
hand. Tug on the base, pulling it towards you. The section of the hinges located on
the base should “snap” apart from the part of the hinges located on the door.

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After installation, simply locate the lid hinges over the installed base hinges and pull
toward you. The hinges should easily “snap” back into place.
By design, the overlapping door of the PVC enclosure makes it inherently drip proof,
although it is not water tight or dust tight. The optional water-tight enclosure has four
screws for sealing the door to the base. Refer to Figure 1-2 on page 2.
3.3. Sensor Mounting Height Recommendations
Some toxic gases such as ammonia (NH3) and combustible gases such as methane
(CH4) are lighter than air, therefore the sensor/transmitter should be installed on or
near the ceiling.
Some toxic gases such as carbon monoxide are only slightly lighter than air, therefore
the sensor/transmitter should be installed at approximately 4’ to 6’ from the floor.
Oxygen sensors should be installed at approximately 4’ to 6’ from the floor.
For toxic gases, combustible gases, and vapors that are heavier than air, the
sensor/transmitter should be installed with the sensor opening at 6” from the floor.
Although most refrigerants (e.g., Freons) are heavier than air, some applications may
be better suited to a slightly higher mounting height for refrigerant sensors.
NOTE: If the area to be monitored is a wet environment, water-tight
enclosures should be used. The water-tight enclosure must be installed
using the indicated holes or it may leak. Damage caused by leaking
because of improperly installed enclosures is not covered under
warranty. If the area to be monitored has the potential for water spray, a
splash guard should be used to protect the sensor.
3.4. Wiring the GDC-150 for Power
If powering the GDC-150 with 24 VAC, use terminals 1 and 2. If powering the
GDC-150 with 24 VDC, the positive (red) wire should be connected to terminal 2 and
the negative (black) wire should be connected to terminal 3. The signal wire is always
connected to terminal 4. See Figure 3-4 for proper wiring examples and Figure 3-5
for improper wiring examples.
Terminals 5, 6, and 7 are used only if the relay option has been supplied. Double
check the relay ratings in the specifications section of this manual before operation.
For normal operation, the relay control wiring should be connected to N/C and COM
(fail-safe operation is used).

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Figure 3-3. Power and Optional Relay Wiring
NOTE: The main wiring terminal strip on the GDC-150 circuit board can
be unplugged for easier wiring installation. Grasp the two sides of the
terminal strip and lift upward with a slight side to side rocking motion.
NOTE: DO NOT use solid-core wire for connection to wiring terminal
strip. Any damage caused by using solid-core wire will void warranty.
Use stranded wire ONLY.
IMPORTANT: The GDC-150 is a low voltage powered device. Any
application of operating voltages higher than indicated in the manual
may result in damage. Double check wiring connections prior to
powering the transmitter. Damage from incorrect wiring connections or
from too much voltage are not covered under warranty.
IMPORTANT: When providing power to the GDC-150, use non-
grounded reference supplies only. Refer to Figure 3-4 for proper wiring
examples and Figure 3-5 for improper wiring examples.

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Figure 3-4. Proper Wiring Examples

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Figure 3-4. Proper Wiring Examples (Continued)
Figure 3-5. Improper Wiring Example
4. OPERATION
4.1. General
After installation, double check wiring prior to applying power to the GDC-150
transmitter. Remember, these are low voltage devices. After power up, the outer
LED will flash green indicating the system is in a warm-up period. During the warm-
up period, the signal output from the GDC-150 is fixed at 4.0 mA. If the digital display
option has been fitted, the LED display will indicate a scrolling decimal “…..” until the
warm-up is completed. If the relay option has been selected, the relay is not activated
during warm-up. The GDC-150 has been programmed with a 5-minute warm-up
period. After the warm-up is completed, the signal output and digital display (if this
option has been supplied) will indicate current gas readings (if any).
If the relay option has been supplied, it will have a factory preset alarm set point (this
can easily be changed in the field). In a non-alarm state, the outer LED will be
illuminated green and the amber relay coil inner LED will be illuminated.The
illuminated relay coil LED indicates to the user that the relay coil is energized. The
relay option on the GDC-150 has been designed to operate in a fail-safe manner,
meaning that the relay coil is energized in non-gas-alarm state and de-energize when
a gas alarm is indicated. The device to be controlled should be connected to the N/C
(normally closed) and COM (common) terminals. In the event of a sensor failure,
anything controlled by the relay is activated continuously until the fail condition has
been corrected.

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4.2. Detecting Gas
Upon detection of the presence of target gas, the signal output increases to a value
equal to the amount of gas being detected by the sensor. If the LED display option
has been supplied, this value will be displayed. If the concentration of gas is above
the preset alarm threshold, the outer LED changes to red, the alarm relay de-
energizes and the amber relay coil LED goes out.
As the detected gas level subsides, the output signal will decrease again to a value
equal to anything being detected by the sensor and this will be indicated on the LED
display (if this option has been selected). The relay will automatically reset after the
signal drops below the set point value.
4.3. System Failure
In the event of a system failure, the outer LED will flash red, the relay will de-energize,
the relay coil LED will go out and the output signal will drop below 4.0 mA. A failure
can consist of a burned out sensor element (solid-state or catalytic), a failed or
damaged component on the circuit board, or a wiring-related problem.
4.4. Sensor Notes
Sensor Type10 Operation Notes
Solid-State
(Refrigerant)
•Not gas specific
•Respond to a fairly wide range of interfering gases and
vapors
•Temperature and humidity compensated to reduce drift in
environments where these values change regularly
Solid-State
(Combustible)
•Not gas specific, but are less likely to suffer from false
alarms from interfering gases (due to the extremely high
measuring range for which they have been calibrated)
Catalytic
(Combustible)
•Specific to combustible gases and vapors
•Temperature compensated
Electrochemical
(E.g., Oxygen)
•These sensors are quite gas specific
•Will respond to some other gases (see cross sensitive
gases table on page 7 for more information)
•Temperature compensation to reduce drift in environments
where the temperature changes regularly
10 Sensors require lengthy warm up and stabilization time after installation. Do not
perform any calibration functions until the sensors have been operating for at least 24
hours.