Greystone AIR-300 User manual

AIR-300
Air Quality Controller
Installation and Operating Instructions
Febuary 15, 2005

Introduction
The Air Quality Monitor uses a tin dioxide semiconductor sensor based on the Taguchi principle to detect oxidizable gases and is
specially designed to have high sensitivity to gaseous organic materials which are components of indoor air pollutants. The sensor is
essentially a heated element inside a porous semiconductive tube. The tube has a large surface area and is able to freely absorb gas
molecules such that electron transfer occurs between the gas and oxygen molecules. This causes a relatively large increase in
conductivity for a small change in gas concentration. This change occurs within a few seconds and is completely reversible.
The sensor responds with varying degrees of sensitivity to a wide variety of gasses which include hydrogen, hydrocarbons, alcohols,
carbon monoxide, benzene, etc. Although the sensor does not detect carbon dioxide, it is still quite useful in human environments since
hydrocarbons, body odours and water vapors are emitted by breathing and perspiration. The levels of these other contaminants change
at roughly the same rate as the carbon dioxide and the sensor will track these other contaminants at approximately the same rate as the
carbon dioxide in occupied spaces.
The Air Quality Monitor may be used as either a stand-alone controller to detect levels of pollution and operate a clean-air damper
directly, or it may be used as a monitor where the analog output signal is transmitted to the Building Automation System for further
processing.
Many different environments can be controlled with careful adjustment of the device parameters so it functions equally well in a school
room where the air is to be kept very clean or a utility room where the fresh air requirements are not as stringent. The Air Quality
Monitor can be used to control intake dampers at an airport where jet fumes are periodic contaminants, automatically control exhaust
air on an assembly line where epoxies are used or a multitude of other applications.
Some common detectable pollutants in decreasing order of sensitivity (most are easily detectable in quantities of 20 ppm or less).
Chemical Symbol Common Source
Methyl Ethyl Ketone C4H8OSolvents and cleaning products
Acetone C3H6OSolvents and organic synthesis
Ethyl Alcohol C2H6OSolvents and liquor fermentation
Formaldehyde CH2ODisinfectants and preservatives
Hydrogen H2Used in synthetics
Methyl Alcohol CH4OSolvents, antifreeze and synthetics
Vinyl Chloride C2HCl Textiles and polymers
Hydrogen Sulfide H2SWater and putrefying matter
Methyl Chloride CH3Cl Solvents, paints and refrigerant
Benzene, Toluene, Xylene C6H6, C7H8, C8H10 Solvents and motor fuels
Trichloroethylene C2HCl3Solvents and cleaning agents
Propane C3H8Fuels and chemical synthesis
Carbon Monoxide CO Combustion of carbon
Freon-22CHClF2Refrigerants and aerosols
Ammonia NH3Solvents and refrigerants
Methane CH4Decomposition and synthesis
Mounting
The AE type room sensor will install directly on a standard electrical box and should be mounted about five feet from the floor of the
area to be controlled. For best operation, do not mount the sensor near doors, opening windows, supply air diffusers or other known
air disturbances.
The D type duct sensor should be mounted on the outside of a return air duct with the air sampling tube inserted into the duct. Install
the sensor in an easily accessible location in a straight section of duct at least five feet from corners and other items that may cause
disturbances in the air flow. Avoid areas such as kitchen fume hoods where oil and grease may contaminate the sensor filter.
Wiring
Use 22 AWG shielded wiring for all connections and do not locate the device wires in the same conduit with wiring used to supply
inductive loads such as motors. Disconnect the power supply before making any connections to prevent electrical shock or equipment
damage. Make all connections in accordance with national and local codes.

This device is a 3-wire sourcing type transmitter. Connect the positive dc voltage or the hot side of the ac voltage to the terminal marked
PWR. The power supply common is connected to the terminal marked COM. The device is reverse voltage protected and will not
operate if connected backwards. This device has a half-wave type power supply so the power supply common is the same as the output
signal common. Therefore, several devices may be connected to one power supply and the output signals all share the same signal
common. Use caution when grounding the secondary of an ac transformer or when wiring multiple devices to ensure that the circuit
ground point is the same on all devices and the controller.
Several output signal options are available from the Air Quality Monitor depending on the model. The standard model is equipped with
an Analog Stepped Output (ASO) signal which is available on the terminal marked ASO. This signal is meant to drive a damper actuator
directly in four discreet steps relative to the OK, LOW, MID and HIGH pollution levels. The signal levels are completely adjustable
and each step can be set anywhere from 0 to 10 Vdc to accommodate any actuator that will accept a 0-10 Vdc control signal. Since all
steps are completely adjustable, the device can also drive a reverse acting actuator.
An optional output signal is available on the LIN terminal. This signal is jumper selectable for either a voltage output or 4-20 mA active
output. In voltage mode the output can also be jumper set for either 0-5 or 0-10 output voltage range. All of these options are clearly
indicated on the device circuit board. The 4-20 mA current output signal operates in the Active mode and does not require a loop power
supply. This means that the signal current is generated by the Air Quality Monitor and must not be connected to a powered input
or device damage will result. Check the controller Analog Input to determine the proper connection before applying power. Both the
current and voltage signals are referenced to the COM terminal. The analog output signal is typically connected directly to the Building
Automation System (B.A.S.) and used as a control parameter or for logging purposes.
A second optional signal is the relay output available on the NO, COM and NC terminals. Note that the relay COM terminal is NOT
connected to the signal COM terminal. The relay output is completely isolated and has both Normally Open (NO) and Normally Closed
(NC) signals. This signal can be used to directly control an alarm, a ventilation fan or may be connected to a digital input of the B.A.S.
for status monitoring.
Start-up
Verify that the Air Quality Monitor is properly wired and all connections are tight. Apply power to the device and note the status LEDs.
Initially the OK LED will be on and the AUTO LED will flash to indicate a four minute warm-up cycle to allow the sensor to reach
normal operating temperature.
The device will enter normal operation after the initial warm-up period. This will be indicated by the AUTO LED being lit and also
one pollution level LED being lit (OK, LOW, MID or HIGH).
The sensor is calibrated at manufacture to be suitable for use in average room conditions. The sensor filter will accumulate dust over
a period of inactive time and the sensor must be allowed to burn-in before proper operation. This time will vary depending on
the storage time but the unit will be suitable for pre-commissioning after about 30 minutes. If the device will be re-calibrated, the unit
should be powered for about three days before making final adjustments. This time is for the sensor output only and the ASO signal
levels may be set immediately after the warm-up cycle.
Operation
The Air Quality Monitor may be operated in two modes, either Automatic or Manual. It is recommended that the device be used in Auto
mode for most applications.
In general, the device compares the amount of contaminants in the air to a base level. The base level is established and adjusted
automatically for best results in the Auto mode or it can be entered manually by the user in the Manual mode of operation. The
comparison of sensor reading to the base level uses a scale factor to determine if the pollution level is considered ok, low, mid or high.
In Auto mode the scale factor is set by the user to control the device sensitivity for different operating environments. In Manual mode
the scale factor is factory set to a predetermined value and cannot be adjusted.
The operation of the device is best understood by relating the various operating points with respect to (wrt) either the 0-5 volt linear
output signal from the device (wrt-output) or to the internal sensor output signal (wrt-sensor) as applicable. Note that the internal sensor
signal is not available to the user but provides a good point of reference to explain the operation. The 0-5 volt output signal is used in
these examples but the 0-10 volt and 4-20 mA outputs are directly scaleable. Typically, the air quality sensor will output about 1.50
volts in clean air and about 4.00 volts in extremely contaminated air (such as when the sensor is close to a burning cigarette). The
following chart will help understand settings such as the scale factor, base level, relay parameters, etc.

Air Condition Examples Internal Sensor Signal 0-5 Volt Linear Output Signal
Clean fresh air 1. 50 volts 1.0 volts = 10 % pollution
Early morning in an un-occupied office 1.75 volts 1.0 volts = 15 % pollution
Smoke from one cigarette in a 300 ft2room 2.00 volts 1.6 volts = 40 % pollution
Coffee break, eight persons in a 300 ft2lunchroom 2.25 volts 2.2 volts = 65 % pollution
Occupied classroom with 30 persons 2.40 volts 2.6 volts = 68 % pollution
Workshop with solvents in use 3.00 volts 4.1 volts = 80 % pollution
Exhaled smoke towards the sensor from 3 ft distance 3.35 volts 5.0 volts = 90 % pollution
Strong chemicals near sensor (ethyl alcohol, nail polish, etc) 4.00 volts 5.0 volts = 100 % pollution
Manual Mode
The manual mode is selected by using the on board keypad and is explained further in the menu section. In this mode the Air Quality
Monitor will operate in the Manual base/Fixed scale mode. In this mode the scale factor (sensitivity) is factory set to 0.2 volts (wrt-
sensor) and cannot be changed by the user. However, the user can set the base level on the keypad. The base level can be set in the range
of 1.0 to 3.5 volts (wrt-sensor) and is displayed on the LEDs as the 5 least significant bits of a 6 bit binary number (63 steps) with the
OK LED being the LSB. During the set-up step, this voltage level can be measured on the ASO terminal with a DC voltmeter.
The processor measures the sensor output 1.50 – 4.00 volt signal and compares it to the base level as set above. If the sensor reads a
value lower than the base level + 0.2 volts the OK LED will be lit, if the sensor reads a value between the base level + 0.2 volts and
the base level + 0.4 volts then the LOW LED will be lit, etc.
The default base level is set to 20 of 63 or about 1.8 volts so the following settings apply: OK Sensor < 2.0 V
LOW 2.0 V < Sensor < 2.2 V
MID 2.2 V < Sensor < 2.4 V
HIGH Sensor > 2.4 V
This mode of operation is useful if the user wants to pre-set a level of air quality which must be maintained. The scale factor has been
optimized for contaminants such as solvents or cigarette smoke. Note that in the manual mode of operation the base level remains fixed
and sensor contamination, temperature or humidity extremes, etc. may cause dampers to stay open for long periods of time.
Auto Mode
The auto mode (factory default) is selected by using the keypad and the Air Quality Monitor will operate in the Auto base/Manual scale
mode. In this mode the base level is automatically adjusted by the program to ensure optimum air quality based on the surrounding
environment and the air handling system. The user can adjust the sensitivity of the device by changing the scale factor via the keypad.
The scale factor has a range of 0.05 to 0.36 V (wrt-sensor) and is displayed on the LEDs as the 5 least significant bits of a 6 bit binary
number (63 steps) with the OK LED being the LSB. See the following example of an LED sequence. The binary range of the scale
factor is (0)00000 to (1)11111 and each count represents about 4.9 mV. This value can be measured on the ASO output terminal.
LED Extra Bit Auto High Mid Low OK
Status Assumed Off On On On On
Binary 0 0 1 1 1 1
Scale Factor 15 x 4.9 mV + 0.05 V = 0.12 V, 001111 = 15
The scale factor represents the sensitivity of the device, a smaller scale factor means more sensitive operation and it will take a smaller
change in the pollution level to give a change in output state. On power up, the base level is initially set to the current air reading. During
operation the device constantly monitors the air quality and compares the contamination level to the base level. If the sensor level falls
below the base level, the base level is adjusted after one minute to equal the air level. This one minute interval of checking is indicated
by a flashing OK LED. This feature always keeps the base level current to the present cleanliness of the air.
If the sensor level increases above the base level, the degree of pollution is determined by comparing the sensor level to the base level
plus multiples of the scale factor. When the pollution level is determined the corresponding LED is lit and the ASO output is updated.
This is the same as the example shown for manual mode except the scale factor can be changed by the user on the key pad.
After pollution has been detected the level must drop below the current level for a period of one minute before the output pollution level
is updated to help ensure against false indication. If the pollution level does not decrease within one hour, then the air is deemed to be

saturated (cannot be improved with fresh air intake) and the base level is raised to equal the current level and the output is set back to
OK.
This cycle is repeated constantly, with the base level being updated as soon as a lower air reading is obtained, to ensure the air quality
is kept at the optimum value and that energy efficiency is not sacrificed.
Menu Configuration
The menu may be accessed any time after the initial warm-up period. The menu is controlled by using the three buttons on the circuit
board labeled MODE, UP and DOWN.
Standard ASO Setup Menu
The standard setup menu has five items as shown below. Pressing the <MODE> switch once while in normal operation will set the
operating mode to step 1, pressing the <MODE> switch a second time saves the value set in step 1 and advances to step 2. Each press
of the <MODE> switch advances the menu item and saves the previous setting to memory. Pressing the <MODE> switch during step
5 will save the value and return to normal operation.
Normal Operation
<MODE> 1. Set OK - allows setting of the OK ASO level
<MODE> 2. Set LOW - allows setting of the LOW ASO level
<MODE> 3. Set MID - allows setting of the MID ASO level
<MODE> 4. Set HIGH - allows setting of the HIGH ASO level
<MODE> 5. Set Base/Scale - allows setting of either the Base level in Manual Mode OR
allows setting of the Scale Factor in Auto Mode
<MODE> Flashes all LEDs and returns to normal operation
The standard menu controls the Analog Stepped Output (ASO). A typical application will have the Air Quality Monitor directly
connected to drive a damper actuator with the ASO to allow fresh air into the controlled area. Once all connections are made and the
warm-up period has elapsed, press the <MODE> switch once. The OK LED will flash to indicate the mode and the ASO terminal will
output an analog voltage corresponding to the OK pollution level. This signal defaults to about 2 V and will drive the damper to open
slightly to allow a minimum amount of fresh air into the area. To modify this value simply press the <UP> or <DOWN> key to increase
or decrease the output signal while watching the damper position. The value will be indicated on the LEDs as a 5 bit binary number
for future reference. When this adjustment is complete, press the <MODE> switch to save the value and advance to the next item.
All values entered are saved in non-volatile memory and will be restored correctly in case of a power failure. The factory defaults and
adjustment ranges are shown in the following table. The LOW, MID and HIGH levels are set in the same way.
Standard Menu Values
Menu Mode Default Value ASO Output Range LED Status
Ok 2 V 0 – 10 V flashing OK, value shown in binary 00000 – 11111
Low 4 V 0 – 10 V flashing LOW, value shown in binary (0 –31 decimal)
Mid 6 V 0 – 10 V flashing MID, value shown in binary as above
High 8 V 0 – 10 V flashing HIGH, value shown in binary as above
Base Level 1.8 V 1.0 – 3.5 V value shown in binary, only for Manual Mode
(0)00000 – (1)11111
Scale Factor 0.12 V 0.05 – 0.36 V value shown in binary, only for Auto Mode
(0)00001 - (1)11111
The Base Level or the Scale Factor menu item is selected automatically depending on the operation mode (Manual or Auto) and is
displayed as a 6 bit binary number on the 5 LEDs. The voltage value is also output on the ASO terminal for verification. These levels
set the sensitivity of the sensor to contaminants and can be adjusted accordingly. The setup is complete for the standard Air Quality
Monitor.

Linear Output
The optional linear output terminal provides either a 0-5 Vdc, 0-10 Vdc or 4-20 mA signal to the automation system to represent the
degree of pollution. This signal is temperature compensated to provide an accurate and reliable method of tracking the air contaminants.
The output signal type is selected via clearly marked jumpers on the PCB. The output voltage or current span represents a level of
pollution between 0 and 100 %.
Relay Output
The optional relay output terminals provide a Form C relay contact for on/off status indication. The relay has two operational modes
which may be menu selected.
The relay may be set to operate in conjunction with the ASO signal which has four distinct levels (OK, LOW, MID and HIGH). In this
mode the relay trip level is set to be either LOW, MID or HIGH and when the ASO pollution level reaches the trip level the relay will
be energized. For example, if the relay trip level is set to HIGH then the relay will energize whenever the ASO indicates a HIGH
pollution level.
The relay may also be set to operate in conjunction with the analog Linear output signal if this option is installed. In this mode the relay
trip level can be set from 1 to 4 Volts (wrt-output) on the 0-5 Vdc output range (20 – 80 % pollution). The other output signal ranges
are scaled accordingly as shown in the following section. In this operation mode the relay will energize when the linear output signal
exceeds the preset trip level. The amount of relay hysteresis may also be programmed via the menu so the relay will turn on when the
linear output is Relay Level + ½ Relay Hysteresis and turn off at Relay Level – ½ Hysteresis.
Configuration Menu
The Configuration Menu is used to set the operation mode, relay modes and for calibration. This menu is accessed during normal
operation by pressing and holding the <DOWN> key and then pressing the <UP> key (then release the keys). This menu is explained
below. <DOWN> (hold key) <UP> Release keys (enters configuration menu)
1. Manual/Auto - selects the operating mode, use the <UP> or <DOWN> key to select, if the AUTO
LED is lit then Auto Mode, if AUTO LED is not lit then Manual Mode, the OK and
LOW LEDs flash to indicate this step
<MODE>
2. Relay Select Mode - sets the relay operating mode as described above, the <DOWN> key selects ASO
mode (indicated by a flashing HIGH LED) and the <UP> key selects the Linear
mode (indicated by a flashing MID LED), the Linear mode will only function
if the hardware option is available
<MODE>
3. Relay Level - if ASO mode is selected can select either LOW, MID or HIGH levels (indicated on
LEDs) by using <UP> or <DOWN> keys
- if Linear mode is selected can set the level between 1 and 4 V on the 0-5 Vdc range
(indicated as a binary number on LEDs) and also output to the Linear output terminal
<MODE>
4. Relay Hysteresis - if Linear mode the relay hysteresis can be set from 0 to 0.606 V on the 0-5 Vdc output
range to prevent relay chatter, this is shown on the LEDs and output to the Linear
output terminal
<MODE>
5. Air Offset Calibration - this menu item allows calibration of the air quality sensor but is not usually adjusted
by the installer, the calibrated sensor value is output on the ASO terminal.
<MODE>
6. Normal Operation - flashes all LEDs and the device returns to normal operation

Configuration Menu Values
Menu Mode Default Value Linear Output Range LED Status
Manual/Auto Auto n/a AUTO LED indicates status
OK and LOW flash
Relay Mode ASO n/a ASO (HIGH LED flashes)
Linear (MID LED flashes)
ASO – HIGH n/a LOW, MID or HIGH LED is lit
Relay Level Linear – 2.5 V
5 V
12 mA
1-4 V on 5 V range
2-8 V on 10 V range
7.2-16.8 on 4-20 mA range
value shown as 5 bit binary
Relay Hysteresis 0.303 V
0.606 V
0.97 (4.97) mA
0 – 0.606 V on 5 V range
0 – 1.212 V on 10 V range
0 – 1.94 (4 – 5.94) mA
value shown as 5 bit binary
only for Linear Mode
Air Offset
Calibration Factory Cal
approx. 1.75 V Sensor output +/- 0.6 V on ASO 6 bit binary value 0-50 00000 to 11111 to (1)10010
Specifications
Measurement . . . . . . . . . . . . . . . . . . Solid State TGS-800 VOC sensor
Sample Method . . . . . . . . . . . . . . . . Diffusion or flow through, sample tube for duct
Power Supply . . . . . . . . . . . . . . . . . . 22-26 Vac, 20-30 Vdc
Consumption . . . . . . . . . . . . . . . . . . . 80 mA @ 24 Vdc, 200 mA @ 24 Vac, 5 VA Max.
Input Voltage Effect . . . . . . . . . . . . . Negligible over specified operating range
Protection Circuitry . . . . . . . . . . . . . . Reverse voltage protected and output limited
Operating Conditions . . . . . . . . . . . . 0-40 °C (32-104 °F), 0-95 %RH non-condensing
Standard Output Signal . . . . . . . . . . Analog Stepped Output (ASO) in four steps representing Ok, Low, Mid and
High pollution levels (each step is independently adjustable from 0-10 Vdc)
Optional Output Signal . . . . . . . . . . Linear output representing 0-100 % pollution level, jumper selectable for either
0-5 or 0-10 Vdc or 4-20 mA (active)
Output Drive Capability . . . . . . . . . . 500 Ωmaximum for current output, 10 KΩminimum for voltage output
Optional Relay Output . . . . . . . . . . . Form C contact, status LED, 5 Amps @ 250 Vac, 5 Amps @ 30 Vdc, p.f. = 1
Display . . . . . . . . . . . . . . . . . . . . . . . 5 LEDs indicating pollution level, operational mode and programming values
Programming and Selection . . . . . . . Via internal push-buttons and jumpers
Wiring Connections . . . . . . . . . . . . . Screw terminal block (14 to 22 AWG)
Enclosures . . . . . . . . . . . . . . . . . . . . AE wall mount enclosure, 2.75”w x 4.65”h x 1.25”d (70 x 118 x 32mm)
Duct mount with sampling tube, 4.8”w x 7.2”h x 2.2”d (122 x 183 x 56mm)

Wiring Diagram
Relay
Connection
(Optional)
20-30Vac/dc
Power Supply /Output
Common
Analog Stepped Output
(to damper actuator)
Linear Output (current or voltage)
(to B.A.S.) (Optional)