Varifan MST-2B User manual

MST-2B
INSTALLATION GUIDE /
USER’S GUIDE
+
ADJUST
MST-2B
2 STAGE
MISTING
12
F2
REL
REDUC.
PER DAY
MIN
MAX
A
L
A
R
M
A
L
A
R
M
L
I
M
I
T
OFF
ON
OFF
Varifan
®
ON
6
12
9
1
11
10
DIFF
DIFF
RH
OFF
S
T
A
G
E
2
S
T
A
G
E
1
22.3

Page 2
MST-2B
Although the manufacturer has made every effort to
ensure the accuracy of the information contained herein,
this document is subject to change without notice due to
ongoing product development.
WARNING AND PRECAUTIONS
Equipment , probe failure, blown fuses and/or tripped
breakers may prove harmful to the contents of the
building. Therefore it is strongly recommended to install
backup devices and alarm or warning devices. Spare
equipment should also be available at the owner’s site.
Equipment manufactured by the manufacturer is protected
against normal line surges. High surges caused by
thunder storms or power supply equipment may damage
this equipment. For added security against line voltage
surges it is recommended that surge and noise
suppression devices be installed at the electrical
distribution panel. Use of shielded cable for probes is
recommended for protection against lightning. These
devices are available from most electrical supply
distributors.
RECOMMENDATIONS
The manufacturer recommends that all installation
procedures described herein be performed by a qualified
electrician or installation technician. Further more the
manufacturer recommends to test all the functions and
equipment connected to the MST-2B, including the alarm
system and backup devices, after installation, after
change to the installation and at least once a month after
that.
Fuse verification and replacement, as well as the proper
setting of control values shall be the responsibility of the
owner of this equipment.

Page 3
CHAPTER 1 - INTRODUCTION
1. General ............................................................................5
1.1 Description .......................................................................5
Definition of terms .........................................................................7
CHAPTER 2 - INSTALLATION
2.1 Unpacking ........................................................................9
2.2 Installation.......................................................................10
2.3 Switch settings ................................................................10
2.3.1 Line voltage selector switch ............................................10
2.3.2 Software setting switches ...............................................11
2.4 Connection procedure.....................................................11
2.4.1 Input power .....................................................................11
2.4.1.1 115 VAC..........................................................................11
2.4.1.2 230 VAC..........................................................................12
2.4.2 Mist output ......................................................................12
2.5 Temperature probes .......................................................12
2.5.1 Single temperature probe ...............................................12
2.5.2 Averaging........................................................................12
2.6 Alarm...............................................................................13
2.7 Powering up ....................................................................13
CHAPTER 3 - USER’S GUIDE
LED status window ......................................................................16
Control dials .................................................................................16
PRIMARY FONCTIONS
Main set point...............................................................................18
Stage 1 differential .......................................................................19
Stage 1 timer run time..................................................................20
Stage 1 timer idle time .................................................................21
Stage 2 relative set point .............................................................22
Stage 2 differential .......................................................................23
Stage 2 timer run time..................................................................24
Stage 2 timer idle time .................................................................25
Ramping.......................................................................................26
Low temperature record...............................................................27
High temperature record ..............................................................28
Ambient room temperature display..............................................29
TABLE OF CONTENTS

Page 4
MST-2B
TABLE OF CONTENTS CONTINUED...
SECONDARY FUNCTIONS
Relative humidity set point ...........................................................30
Minimum Ramping .......................................................................31
Low Temperature Alarm...............................................................32
High Temperature Alarm..............................................................33
Relative humidity display..............................................................34
APPENDIX
Troubleshooting ...........................................................................35
Technical specifications ...............................................................36
Record form .................................................................................37

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1. GENERAL
This manual provides the information necessary for the
installation and operation of an MST-2B unit. The
information is presented as follows:
•Introduction
•Installation
•User’s Guide
•Troubleshooting
1.1 DESCRIPTION
Congratulations on the purchase of your MST-2B. The
MST family products allow full control over temperature
using evaporative cooling, resulting in a comfortable
environment for your livestock.
The MST family products offer the following features:
•Display of the highest and lowest temperatures
recorded.
•Automatic daily reduction of the temperature set point.
The MST-2B is a two-stage evaporative cooling (timed)
controller. Optionally, a humidity probe may be used to
prevent evaporative cooling operation if humidity level is
too high.
CHAPTER 1 - INTRODUCTION
CHAPITRE 1 - INTRODUCTION

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MST-2B
DESCRIPTION CONTINUED...
The MST-2B keeps you informed of the output status as well
as the actual ambient temperature by displaying them
constantly.
An alarm will warn you if the ambient temperature is not
within the pre-established limits. The output is protected by a
fuse and all programmed parameters are preserved, even
when the MST-2B is not powered.
The MST-2B offers automatic daily reduction of the
temperature set point (Ramping) as the livestock matures. A
minimum temperature set point is used to insure that the
ramping function never diminishes below a critical limit.

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DEFINITION OF TERMS
MAIN SET POINT
The desired room temperature. All other temperature
parameters adjusted in the MST-2B are relative to this
reference temperature.
AMBIENT TEMPERATURE
The ambient room temperature.
RAMPING
Automatic daily reduction of the main set point.
CHAPTER 1 - INTRODUCTION

Page 8
MST-2B

Page 9
CHAPTER 2 - INSTALLATION
2.1 UNPACKING
Unpack the MST-2B and inspect contents for damage.
Should the contents be damaged, contact your local
distributor to return the material.
The package should contain the following standard items:
•1 MST-2B control.
•1 installed temperature probe (model number:
2004-1KLT).
•1 fuse.
•1 installation guide / user’s guide.
The following optional items may be included:
•3 additional temperature probes for temperature
averaging.
•1 RH-3 humidity probe (blue cable) or RHT-1.
The manufacturer recommends
following the installation instructions
of the present guide and that all
procedures be done by a certified
electrician. Failure to comply may void
the warranty!
CHAPTER 2 - INSTALLATION

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MST-2B
2.2 MOUNTING
Install the MST-2B using the mounting holes drilled in the
side of the casing.
Once the MST-2B is in place, use a screwdriver to remove
the faceplate.
2.3 SWITCH SETTINGS
To limit the unit’s exposure to noxious gases install the
unit in a hallway.
Make sure the unit is mounted right side up with the
cable entry holes facing down.
The MST-2B must operate in a temperature range of
32°F - 120 °F (0 °C - 50 °C).
The enclosure is watertight, but it is not splash proof or
immersion proof. DO NOT SPRAY the control. Cover the
control carefully with plastic when cleaning the room.
It is prohibited to use overhead cables outside the
building
Mounting hardware is not included with the
unit.
2.3.1 - LINE VOLTAGE SELECTOR SWITCH
This switch is located on the surface of the main (bottom)
board and adapts the MST-2B for 115 VAC or 230 VAC
line voltage.
Refer to figures 1 and 2.
230V
115V

Page 11
Certain parameters of the MST-2B are configured by the following
switches:
2.3.2 Software setting switches
These switches are located at the rear of the MST-2B
faceplate and are used to adjust the following options:
1
2
3
4
Switch 1 Selects the measuring unit (Celsius or Fahrenheit)
in which temperature values will be displayed on the front
panel.
Switch 2 Settings locked/unlocked. All parameters except
the Main Set Point, the High Temperature Record and
the Low Temperature Record are locked when this switch
is set to "OFF".
2.4 CONNECTION PROCEDURE
For the following connection procedures, refer to figure 1.
2.4.1 - Input power
Use a screwdriver to remove the pre-cut parts for the
connection of the cables to the main board.
2.4.1.1 - 115VCA
Make sure the line voltage selector switch is set to
115VAC. Connect the power cable to terminals 3 and 4 on
the main (bottom) board.
Do not supply power to the MST-2B until all
connections have been completed!
OFF ON
Fahrenheit
Settings locked
Reserved
Reserved
Celsius
Settings unlocked
Reserved
Reserved
OFF ON
CHAPTER 2 - INSTALLATION

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MST-2B
2.4.1.2 - 230VCA
Make sure the line voltage selector switch is set to
230VAC. Connect the power cable to terminals 3 and 4 on
the main (bottom) board.
2.4.2 - Mist output (terminals 5 and 6)
The relay can drive a load of 10 Amp maximum.
2.5 TEMPERATURE PROBES
The temperature probes use a low-voltage class 2 circuit.
The cables (AWG#18 min) can be up to 500 feet (150
meters) in length. For cables longer than 10 feet (3 meters)
use an aluminium-shielded wire which must be connected
to the common of the input power. Temperature probe
connections are illustrated in figure 2 whereas connections
for temperature probe averaging are shown in figure 3.
2.5.1 - Single temperature probe
Install the temperature probe in a location that best reflects
the overall room temperature. Connect the two leads and
the shield of the probe to the terminals labelled “Probe” as
indicate in figure 2.
2.5.2 - Averaging (optional)
Four temperature probes are required to do temperature
averaging in larger rooms. Place the probes in appropriate
locations to best average the room temperature. Refer to
figure 3.
Install low voltage wires (probes, computer link or
potentiometer wires) at least 12 inches (30 cm) away from
high voltage wires (120/230VAC, 24VDC). Always cross
high and low voltage wires at a 90-degree angle.

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2.6 ALARM
The MST-2B provides a normally open and normally
closed dry contact for alarming low or high temperature
conditions. In addition, that same contact may be used to
signal a power failure. This contact may be connected to
an alarm system, or directly to a siren and/or an auto-
dialer.
Make the normally open or normally closed connections as
shown in figure 2.
2.7 POWERING UP
Before powering up the MST-2B, attach the faceplate to
the casing of the MST-2B using the four screws previously
removed.
Set the selector knob to position (12).
Upon powering up, the unit will test its LED display by
lighting up all of its segments. Make sure all segments light
up at this moment.
Following the LED display test, the unit will display the
room temperature.
If the temperature is not displayed, refer to the
Troubleshooting section in the appendix of this manual.
Momentary power interruptions may trigger false alarms!
To avoid false alarming when the MST-2B is connected to
an alarm system, install a time delay relay between the
MST-2B and the alarm system.
CHAPTER 2 - INSTALLATION

Page 14
MST-2B
Fig. 1
Wiring diagram for the mister output.
Note for figure 1.
Power cut and protection devices in case of an overload..
1
Fig. 2
Probe and alarm connection.
Optional humidity probe
WHITE
BLACK
RED
RH-3
blue connector

Page 15
CHAPTER 2 - INSTALLATION
Fig. 3
Probe connection for temperature averaging.
Fig. 4
Main (bottom) Board: Terminal blocks, switches and fuse
location.
Terminal Block
Probe #1
Probe #2
Probe #3
Probe #4
It is recommended to solder
the probes’ junctions
IN
GND
Shield

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MST-2B
CHAPTER 3 - USER’S GUIDE
The MST-2B front panel shown above features a LED
status window and two control dials which are respectively
used to select a function and adjust a setting.
LED STATUS WINDOW
The LED status window features a 3 digit LED display for
temperature in Fahrenheit or Celsius, and programmable
settings.
In addition, the LED status window displays the operational
state of the mist output and the alarm via four additional
LEDs (shown above in LED window). The first LED is
continuously illuminated when the mist is activated using
the first stage timer. The second one indicates that the mist
is active on the second stage timer. If one of the LEDs is
blinking, this indicates that the mist is on the inactive
portion of the respective timer. The third LED is lighten
when the mist is shut off due to a high humidity level.
Finally, the fourth LED will light up if the high or low
temperature limit is exceeded.
CONTROL DIALS
The center dial is the selector dial and is used to select one
of the control panel’s 12 primary or 5 secondary functions.
The dial located to the right of the selector dial is the
adjuster dial and is used to enter secondary function mode
and to adjust the setting of each function.
+
ADJUST
12
F2
REL
REDUC.
PER DAY
MIN
MAX
A
L
A
R
M
A
L
A
R
M
L
I
M
I
T
OFF
ON
OFF
ON
6
12
9
1
11
10
DIFF
DIFF
RH
OFF
S
T
A
G
E
2
S
T
A
G
E
1
22.3

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CHAPTER 3 - USER’S GUIDE
The 12 primary functions are:
•1 Main Set Point
•2 Stage 1 differential
•3 Stage 1 timer run time
•4 Stage 1 timer idle time
•5 Stage 2 RSP
•6 Stage 2 differential
•7 Stage 2 timer run time
•8 Stage 2 timer idle time
•9 Ramping
•10 Low temperature record
•11 High temperature record
•12 Ambient temperature display
Any one of these functions is selected by rotating the
selector dial to the corresponding number and associated
graphical image printed on the faceplate of the MST-2B.
When primary functions 1 through 11 are selected, the
LED status window displays a blinking value. Function 12
displays room temperature.
The 5 secondary functions are:
•1 Humidity set point
•9 Ramping minimum temperature limit
•10 Low temperature alarm
•11 High temperature alarm
•12 Relative humidity display
Select any one of these secondary mode functions by:
•rotating the Selector dial to (12)
•rapidly rotating the adjuster dial back and forth to enter
secondary mode.
•rotating the selector dial from function (12) to any other
function.
When secondary functions 1 and 9 through 11 are
selected, the status window displays a blinking value along
with a scrolling LED display. Returning the selection to
function 12 removes the MST-2B from the secondary
function mode.

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MST-2B
The main set point establishes the target
temperature in the building. This value is used as
the reference point for other settings.
The main set point temperature is adjusted in 0.5-
degree increments from a minimum setting of
13.5°F (-9.5°C) to a maximum setting of 105.0°F
(41.0°C).
Adjusting the main set point temperature:
•rotate the Selector dial to position (1),
•rotate the Adjuster dial counter clockwise to
decrease the temperature setting, and
clockwise to increase it.
The main set point temperature is displayed on
the MST-2B.
PRIMAIRY FUNCTIONS
MAIN SET POINT
Note: The ramping feature
(primary function 9) must
be (OFF) to adjust the main
set point.

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CHAPTER 3 - USER’S GUIDE
STAGE 1 DIFFERENTIAL
This value represents the temperature decrease
that must be reached to stop mist operation on
stage 1 timer.
The differential is adjusted in 0.5-degree increments
from a minimum setting of 0.5°F (0.5°C) to a
maximum setting of 10°F (5.0°C).
Adjusting stage 1 differential:
•rotate the Selector dial to position (2),
•rotate the Adjuster dial counter clockwise to
decrease the differential, and clockwise to
increase it.
The stage 1 differential is displayed on the
MST-2B.

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MST-2B
STAGE 1 TIMER RUN TIME
Stage 1 timer is activated when ambient
temperature reaches the main set point. When the
mist output is activated using this timer, the LED
directly beneath the number “1” will be continuously
illuminated.
The stage 1 timer run time is adjusted in 1-minute
increments from a minimum setting of 1 minute to a
maximum setting of 60 minutes.
Adjusting stage 1 timer run time:
•rotate the Selector dial to position (3),
•rotate the Adjuster dial counter clockwise to
decrease the run time, and clockwise to
increase it.
The stage 1 timer run time is displayed on the
MST-2B.