Mircom OpenBAS-HV-WLSTH User manual

Mircom OpenBAS-HV-WLSTH Operating manual
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OpenBAS-HV-WLSTH wireless thermostat transmitter for
VAV / Fan & Coil / Mini split / Water source applications
The OpenBAS-HV-WLSTH wireless temperature and humidity transmitter and thermostat,
works matched to a OpenBAS-HV-VAVFC receiver controller to provide an easy to set up
HVAC control for end HVAC end unit applications such as: VAV boxes, fan and coil units,
mini split and water source chiller / heat pump units.
OpenBAS-HV-VAVFC receiver unit for VAV / FAN & COIL applications

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The OpenBAS-HV-WLSTH works in the 433 MHz unlicensed band providing a RF link
with a matched receiver to up to 100 meters in line of sight applications and 50 meters
indoors.
When used in wireless applications it is powered by two AA alkaline batteries which
provide , up to two years of operation, depending on the transmission rate that can be set
between a 10-30 seconds periods.
The thermostat can also be optionally powered by any external power supply (not included)
that provides any voltage between 9-24 Volts either AC or DC. Power consumption is very
low, being only 0.0005 VA when used wireless and 0.05 VA when used with the RS485
wired interface
To integrate the wireless temperature / humidity transmitter into any NX controller with an
I2C connector, the OpenBAS-HV-RF433R receivers can receive the signal from up to 10
transmitters into the NX controllers and send their information via the I2C bus
OpenBAS-HV-RF433R receiver unit for I2C bus
It also comes standard with an integrated RS485 port supporting multiple protocols such as:
BACnet/MSTP, Modbus-RTU, Optomux, N2-Open and terminal ASCII mode.
Either wireless or wired it can be integrated to any network and used as a standard
temperature and humidity transmitter or using all its integrated features and user available
set points, be used as a powerful yet easy to set environment HVAC controller.
It is fully addressable, when used wirelessly it can be programmed into a group out of 10,
and each group can have up to 99 individual addresses.
When used wired it can be set an address depending on the protocol between 1 and 199.

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Component description for OpenBAS-HV-WLSTH transmitter:
Programmer
connector
Two
1.5 volts
AA alkaline
batteries
Temperature and
humidity sensor
Alternate
power supply
and RS485 bus
connector
Temperature
decrease
button
Manual / auto
fan speed
button
LCD display
Transmit LED
Temperature
increase
button
On / Off
button
Back Front
Antenna
Multiple transmitters can be linked to a single receiver or to multiple receivers, depending
on the application, each receiver can be set up to filter out up to 10 receivers and use that
information for its HVAC control loop as shown on the next figure:
Transmitters Receivers
1
2
3
4
5
i2c receiver pair + NX10
VAV box controller
F&C controller
In the above figure, can be seen that a transmitter can send information to one or more
receivers (unlimited number of receivers), and also any one receiver can receive
information from one and up from ten different transmitters.

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Keyboard operation
The following diagram depicts the button names from the keyboard as they will be
described on the rest of this user manual.
Temperature
decrease
button
Temperature
increase
button
On / Off
button
Manual / auto
fan speed
button
DEC
MAN/AUTO
INC
ON/OFF
The ON/OFF button toggles either ON or OFF the HVAC equipment it controls. If the
control is in the OFF mode, the LCD display will only show two hyphens on the screen.
If the equipment is in the ON mode, the screen will show either the current temperature if it
is in AUTO mode or the speed (velocity) of the fan if it is in the MANUAL mode. The
MAN/AUTO button toggles this setting.
/
OFF AUTO MODE MANUAL MODE
/
Also depending on the automatic or manual mode, the increment INC and decrement DEC
buttons will work differently.
In the automatic mode, pressing either of the INC or DEC buttons will decrease the
temperature set point (colder) or increment it (warmer).
In manual mode, the increment INC and decrement DEC buttons will change the fan to
LOW, MEDIUM or HIGH speed.

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Fan & Coil, Mini Split and Water source heat pump operation
For Fan & Coil and mini Split operation, the thermostat will depending on the current
temperature, the set point and the proportional band, change the speed of the fan (if the auto
mode is selected) and turn on or off the cooling or heating stages as needed (regardless of
the auto / manual mode).
This behavior can be better viewed on the picture below.
Cool/Heat valves
Fan LOW
Fan MED
Fan HIGH
Fan LOW >> MED
Fan MED >> HIGH
Fan MED << HIGH
Fan LOW << MED
Valve ON
Valve OFF
SP PB PB PB
+
1/2 °C
-
1/2 °C
The operating set point as well as the unoccupied set points can be independently adjusted
within the range of 19-27 °C or their equivalent in Fahrenheit 66-80°F.
Proportional band can be set to 1 or 1.5 or 2 °C.
In manual mode the fan speed can be set to low / medium / high.
In any operation mode the cool and heat outputs are managed by the current active point,
occupied or unoccupied.

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Variable air volume (VAV) box operation
For VAV operation, the thermostat will depending on the current temperature, the set point
and the proportional band, output a 0 to 100% signal on the analog output (0 to 10 Volts) to
position the VAV actuator accordingly (regardless of the auto / manual mode).
PB SPSP
CoolingHeating
100%
0%
100%
0%
In the case the actuator is of the incremental type, and has an open and close terminals
which are driven by two of the relays from the controller, the VAV/F&C controller will
automatically turn the corresponding output on and off for a certain period of time to
position the actuator.
If the actuator has a feedback resistor mounted directly on the shaft the controller uses this
as a feedback reference.
If the pressure sensor is used, the pressure differential will be used to calculate the current
position of the valve for pressure independent VAV box control.

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Programming modes
The wireless transmitter can be programmed beyond the user set points to commission it for
the correct operation that matches the intended use.
Press and hold the button
for 5 seconds to enter basic
programming mode
MAN/AUTO
Press and hold the button for
10 seconds to enter advanced
programming mode
The following list shows the set points that can be programmed in the basic programming
mode:
°C Celsius or Fahrenheit display.
SU Unoccupied temperature set point adjust.
SH Humidity set point adjust.
The following list shows the set points that can be programmed in the advanced
programming mode:
T1 Time to change from occupied to unoccupied mode in minutes (5 to 30).
CT Calibrate temperature sensor (+/- 10 °C).
CH Calibrate humidity sensor (+/- 10 %RH).
PB Proportional band adjust (1(1) or 1.5(2) or 2(3) °C).
PG Type of program (1 to 9).
GR Wireless group (1 to 10) or wired protocol (11 to 15).
AD Wireless addresses (1 to 199) or wired address (1 to 199*).*Bacnet 5-127
br Baud Rate (24(00), 48(00), 96(00), 19(200), 38(400), 57(600) and 76(800).
PA ModBus Parity No(ne)/ Ev(en)/ Od(d).
TT Wireless transmit timer in seconds (10 to 30).
BV Battery voltage.
°C Celsius or Fahrenheit display.

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SU Unoccupied temperature set point adjust.
SH Humidity set point adjust.
Basic programming mode
In this basic programming mode, only the most three basic adjustments can be made.
First the units being displayed can be selected between Celsius or Fahrenheit degrees by
selecting the INC or DEC buttons.
/
If no button activity is detected within 20 seconds the thermostat will revert automatically
to normal operation mode.
To skip to the next parameter, the ON/OFF button will jump to the next setup screen; here
the unoccupied set point can be changed with the INC and DEC buttons, the value can be
adjusted within the range of 19-27 °C or their equivalent in Fahrenheit 66-80°F
/
If no button activity is detected within 20 seconds the thermostat will revert automatically
to normal operation mode.
To skip to the next parameter, the ON/OFF button will jump to the next setup screen; here
the humidity set point can be changed with the INC and DEC buttons, the value can be
adjusted within the range of 0 to 100 %RH.
/
If no button activity is detected within 20 seconds the thermostat will revert automatically
to normal operation mode, or to finish basic programming mode press one last time the
ON/OFF button.

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Advanced programming mode
In this programming mode, all parameters can be adjusted. To enter advanced programming
mode press and hold the MAN/AUTO button for 10 seconds, and release it when the T1
display appears on screen.
Time to go to unoccupied mode
This time to change from o unoccupied mode is used by the receiver controller, to change
from occupied to unoccupied mode if a combination of door and motion senor is used to
detect occupancy automatically. The range to adjust this time is from 5 to 30 minutes.
/
To jump to the next parameter press the ON/OFF button. If no button activity is detected
within 20 seconds the thermostat will revert automatically to normal operation mode
Calibrate temperature sensor
The digital i2c temperature and humidity sensor comes factory calibrated within a 1°C
accuracy, if however it needs to be calibrated against a well-known accurate temperature
reference, on this next screen the value being read can be adjusted within a +/- 10°C range
in 0.1°C steps. The default calibration value is cero.
/
Negative sign
Because there is no decimal point on the display, the values between 0 to ±99 represent an
offset from ±1.0 to 9.9 °C respectively.
Note that negative values are shown with a rotated “-“ sign for values bigger that 0.9°C as
the LCD does not have a horizontal segment to display negative values for values greater
than -9 (-0.9°C), adjust the value using the INC and DEC buttons.
To jump to the next parameter press the ON/OFF button. If no button activity is detected
within 20 seconds the thermostat will revert automatically to normal operation mode.

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Calibrate humidity sensor
The digital i2c temperature and humidity sensor comes factory calibrated within a 2 %RH
accuracy, if however it needs to be calibrated against a well-known accurate humidity
reference, on this next screen the value being read can be adjusted within a +/- 10 %RH
range in 0.1 %RH steps. The default calibration value is cero.
/
Negative sign
Because there is no decimal point on the display, the values between 0 to ±99 represent an
offset from ±1.0 to 9.9 %RH respectively.
Note that negative values are shown with a rotated “-“ sign for values bigger that 0.9 %RH
as the LCD does not have a horizontal segment to display negative values for values
greater than -9 (-0.9 %RH), adjust the value using the INC and DEC buttons.
To jump to the next parameter press the ON/OFF button. If no button activity is detected
within 20 seconds the thermostat will revert automatically to normal operation mode.
Proportional band set up
The proportional band can be adjusted for 1°C or 1.5°C or 2°C for a fine or coarser control
of the HVAC loop. The default value is 1°C.
/
Because there is no decimal point on the display, the values 10 , 15 and 20 represent the
1°C or 1.5°C or 2°C respectively, adjust the value using the INC and DEC buttons.
To jump to the next parameter press the ON/OFF button. If no button activity is detected
within 20 seconds the thermostat will revert automatically to normal operation mode.

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Select the HVAC program
The program for both the transmitter and the receiver can be set in this parameter, the
following programs are available:
1. VAV box with pressure sensor for pressure independent operation.
2. VAV boxes no pressure sensor for pressure dependant operation.
3. Fan and coil, cool only.
4. Fan and coil, heat only.
5. Fan and coil, auto cool / heat switchover.
6. Mini split unit, cool only.
7. Mini split unit, heat only.
8. Mini split unit, auto cool / heat switchover.
9. Chiller / Heat pump one stage.
10. Chiller / Heat pump two stages.
/
Select the desired program using the INC and DEC buttons.
To jump to the next parameter press the ON/OFF button. If no button activity is detected
within 20 seconds the thermostat will revert automatically to normal operation mode.

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Select the wireless group or wired protocol
For wireless operation a group must be selected between values of 1 to 10, each wireless
group can have up to 199 addresses.
If instead a value between 11 to 15 is selected, the wired interface will be used instead, and
the address will represent the address of the RS485 interface on the bus.
/
Group/Prortocol Protocol Address range
1 to 10. Wireless group 1 to 199.
11. ASCII terminal protocol No addressing possible on this protocol.
12. Optomux protocol 1 to 199.
13. N2-Open protocol 1 to 199.
14. Modbus RTU protocol 1 to 199.
15. BACnet/MST protocol 5 to 127.
Select the desired group or protocol using the INC and DEC buttons.
To jump to the next parameter press the ON/OFF button. If no button activity is detected
within 20 seconds the thermostat will revert automatically to normal operation mode.
Wired or Wireless address
The address for either the wired or Wireless interface depending on the setup of the
previous group / protocol setting can be set on this screen,
.
/
Select the desired address using the INC and DEC buttons.
To jump to the next parameter press the ON/OFF button. If no button activity is detected
within 20 seconds the thermostat will revert automatically to normal operation mode.
.

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NOTE:
Each Wireless group can have up to 199 addresses, so up to 1990 transmitters can
theoretically be installed within a 100 meters radius of the transmitter’s wireless
range without addressing issues for the 10 groups.
However it is not recommended to have two transmitters with the same group/address
pair within the 100 meters range of each transmitter to avoid a receiver to receive the
packages from two different transmitters with the same group/address pair which
could cause erratic operation in the receiver’s logic.
Wireless transmission time interval
This interval can be set to be 10, 15, 20 or 30 seconds. Having a shorter interval between
transmissions will decrease the latency for the receiver to have more frequent samples per
minute, but will as well reduce battery life, increasing the transmission time will have the
opposite effect.
The transmitter has an internal random time shifting algorithm that modifies the
transmission interval within a ±20% range to avoid repeated over the collisions of two
nearby transmitting sensors with the same interval period. The default value is 20 seconds.
/
Select the desired transmission time interval using the INC and DEC buttons.
To jump to the next parameter press the ON/OFF button. If no button activity is detected
within 20 seconds the thermostat will revert automatically to normal operation mode.

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Battery voltage
The battery voltage is visible on this screen; the voltage is shown without decimal points so
for example a value of 33 means 3.3 Volts.
/
When the voltage falls below a voltage that indicates that 90% of the energy of the battery
has been depleted, a low battery sign will blink on the main display while the transmitter is
operating in normal mode.
/
Any time this message blinks on the screen, the battery life will only last between 1-2 more
months.
To jump to the next parameter press the ON/OFF button. If no button activity is detected
within 20 seconds the thermostat will revert automatically to normal operation mode.
Temperature units to display
The temperature units being displayed can be selected between Celsius or Fahrenheit
degrees by selecting the INC or DEC buttons.
ó
To jump to the next parameter press the ON/OFF button. If no button activity is detected
within 20 seconds the thermostat will revert automatically to normal operation mode.

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Set point unoccupied mode
The unoccupied set point can be changed with the INC and DEC buttons, the value can be
adjusted within the range of 19-27 °C or their equivalent in Fahrenheit 66-80°F
/
To jump to the next parameter press the ON/OFF button. If no button activity is detected
within 20 seconds the thermostat will revert automatically to normal operation mode.
Set point humidity
The humidity set point can be changed with the INC and DEC buttons, the value can be
adjusted within the range of 0 to 100 %RH.
/
To finish and exit programming mode, press the ON/OFF button. If no button activity is
detected within 20 seconds the thermostat will revert automatically to normal operation
mode.
A display showing parameters were stored in Eeprom will briefly show on the display.
During normal automatic operation the temperature on the selected units and the relative
humidity %RH will alternate. The temperature will be shown for 10 seconds, then a display
showing the RH will show for one second and finally the humidity will be shown for 4
seconds, then the display will revert to show the current temperature.
If the thermostat is in manual mode, the speed (velocity) of the fan 1, 2, 3 for Low,
Med/High will be shown instead.

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