VH7200 Humidistat Series
For Humidification & Dehumidification Control
For Commercial HVAC Applications
(Issue Date September 29, 2008 – 028-0208 R4)
Product overview
The VH7200 humidity controller family is specifically designed for control of
humidification and dehumidification equipment such as steam header direct
injection, desiccant wheel, or stand alone humidification / dehumidification
equipment. The product features a complete embedded humidity control
solution with an intuitive backlit LCD display that walks the installer through the
configuration steps, making the process extremely simple. Accurate relative
humidity control is achieved due to the product’s unique PI time proportional
control algorithm, which virtually eliminates humidity offset associated with
traditional, differential-based humidity controllers.
All models contain a binary input, which can be set by the user to monitor an
electrode humidifier canister service status or may be used as a general
purpose service indicator. Models are available which contain more advanced
features such as discharge humidity proportional high limit, and indoor humidity
setpoint reset based upon outdoor air temperature to conserve energy and
eliminate condensation on windows and structure.
The additional following documents are available at:
• Information on the BACnet models (VH72xxX1000B), is available on document ITG-VH7200-BAC-Exx
www.viconics.com
Models available
Model with Outdoor reset & Proportional High Limit VH7270K1000 (X)
Application Model Number
Humidification
On/Off 24 Vac
Fig.1 VH7200 series humidistats
Dehumidification
Output(s)
0-10 Vdc &
On-Off 24 Vac
Output
Model with Outdoor reset & Proportional High Limit VH7270F1000 (X) 0-10 Vdc On-Off 24 Vac
Models with outdoor reset only VH7200A1000 (X) On/Off 24 Vac On-Off 24 Vac
* NEW * Duct Mount Model with Outdoor reset &
Proportional High Limit
(X) model number represents available communication options: X=none for Stand-alone and X=B for BACnet MS-TP.
VH7270D1000 (X) 0-10 Vdc On-Off 24 Vac
Features and benefits
Features Benefits
• Embedded humidification and dehumidification
sequences
⇒ Simplifies installation and reduce installation
costs
• Embedded internal RH sensor ⇒ Eliminates components
• Proportional high limit override
• (VH7270 Models Only)
• Humidity setpoint reset based on outdoor
temperature
⇒ Prevents costly damage due supply humidity
condensation
⇒ Saves energy and prevents window
condensation in colder climates
• Sensor failure protection ⇒ Prevents water damage
• PI time proportioning algorithm ⇒ Increased comfort, accuracy, and energy savings
• Binary input ⇒ Adds functionality (Trigger service alarms )
• Unique configuration menu routine ⇒ Minimizes parameter tampering
• Lockable keypad ⇒ Tamper proof, no need for humidistat guards
• EEPROM memory ⇒ No loss configuration parameters
• Optional remote humidity sensors ⇒ Increase flexibility and functionality
028-0208 R4_LIT-VH72x0-E14.doc
www.viconics.com / sales@viconics.com
Features overview
• Internal RH sensor and optional remote RH input with embedded humidification and dehumidification sequence
of operation.
• Humidity set point reset based upon outdoor temperature sensing for added flexibility.
• Proportional high limit input to prevent over-humidification due to supply humidity condensation.
• Lockable keypads for tamper proofing. No need for extra humidistat guard.
• Programmable binary input for added flexibility. The input can be programmed as the following:
- None: No function will be associated with the input
- Service: a backlit flashing Service alarm will be displayed on the humidistat LCD screen when the input is energized. It can be tied in to the AC unit control card, which provides an alarm in case of malfunction.
- Canister: a backlit flashing Canister alarm will be displayed on the humidistat LCD screen when the input is energized. It can be tied to a Dry contact output supplied by others.
Installation
• Remove security screw on the bottom of humidistat cover.
• Open up by pulling on the bottom side of humidistat.
• Remove Assembly and remove wiring terminals from sticker.
(Fig. 2)
A) Location:
1- Should
not be installed on an outside wall.
2- Must be installed away from any heat source.
3- Should not be installed near an air discharge grill.
4- Should not be affected by direct sun radiation.
Fig.2
5- Nothing must restrain vertical air circulation to the
humidistat.
B) Installation:
1- Swing open the humidistat PCB to the left by pressing the
PCB locking tabs. (Fig. 3)
2- Pull out cables 6” out of the wall.
3- Wall surface must be flat and clean.
4- Insert cable in the central hole of the base.
5- Align the base and mark the location of the two mounting
holes on the wall. Install proper side of base up.
Fig.3
6- Install anchors in the wall.
7- Insert screws in mounting holes on each side of the base.
(Fig. 3)
8- Gently swing back the circuit board on the base and push
on it until the tabs lock it.
10- Strip each wire 1/4 inch.
11- Insert each wire according to wiring diagram.
13- Gently push back into hole excess wring (Fig. 4)
14- Re-Install wiring terminals in correct location. (Fig. 4)
15- Reinstall the cover (top side first) and gently push back
extra wire length into the hole in the wall.
16- Install security screw.
Fig.4
For VH7270D1000 duct-mount model only:
1- Make 1” diameter hole in duct wall
2- Insert the duct sensor and fix the electrical box to the
duct wall in the vertical position (respect airflow
direction).
3- Install the humidistat to the electrical box using the
supplied screws (2).
4- Follow steps 1-16 above.
2
Wiring
3
Terminal identification & screw terminal arrangement
Part Number VH7270K VH7270D/F VH7200A
Top left terminal block
1 Not used Not used Not used
2 HUM
3 HUM
4 R
5 C
X
X
X X X
X X X
Not used
Not used
X
X
Top right terminal block
6 DEH
7 DEH
X X X
X X X
8 Not used Not used Not used
Bottom terminal block
9 Not used Not used Not used
10 Not used Not used Not used
11 HUM 0-10
12 DI1
13 HS
14 SCOM
15 OS
16 HL
X X
X X X
X X X
X X X
X X X
X X
Fig.5 : VH7200’s wiring terminals
Not used
Not used
Wiring notes:
Note 1:
Reference of the analog 0-10 Vdc control signal
is the common of the power supply of the
humidistat. (terminal C)
Note 2:
Electromechanical dry contact is to be used with
the binary input. Electronic triacs cannot be used
as mean of switching for the input. The switched
leg to the input for the input to activate is
terminal Scom
Note 3:
The transformer of the unit provides power to
the humidistat and any additional loads wired
to the humidistat.
Note 4:
Both the remote humidity sensors ( HS & HL
terminals ) use 0 to 10 Vdc type humidity
sensors.
Detailed wiring diagram for model VH7270K1000
R.A. S.A.
HumidificationOutput :
( On/Off ) or ( 0- 10 Vdc )
Refer to parameter:
"SeqOpera"
VH2030D1000
OPTIONAL
DUCT
MOUNTED
HUMIDITY
TRANSMITTER
VH2030W1000
OPTIONAL
WALL
MOUNTED
HUMIDITY
TRANSMITTER
Note:
Whenaremote
humidity
transmitter
is connected to
the VH7200,
it's internal
humidity
sensor is
au
tomatically
disabled.
VH7270K1000
HUMIDITY CONTROLLER
HUM
HUM
or
HUM
0-10
R C
DEH
DEH
Scom
HSDI1 OS
FLOW
(On/Off) HUMIDIFIER
H
H
Dry contact
Dry contact
HL
S202 00
0E1000 or S2000D10
OP
TIONAL OUTDOOR
TE R
MPERATURE SENSO
SWITCH
Dehumidification
air exchanger
and/or
(0-10 Vdc)
HUMIDIFIER
Com
0-10
24V
FLOW
SWITCH
XX
Binary Input "Di1" Set
for "SER VICE" alarm
VH2030D1000
HUMIDITY TRANSMITTER
(OPTIONALHIGH LIMIT)
24 Vac
COM. 0-10Vdc
K
C
A
L
B
E
D
E
G
R
N
A
R
O
Fig.6 : VH7270F1000 wiring diagram
Specific wiring diagrams for all models VH7200A1000, VH7270F1000, VH7270K1000
4
24 VacHot
On/Off Humidification
On/Off Humidification
VH7270K1000 Universal
Analog 0-10 Vdc Humidification
Digital input, dry contact to "Scom"
Remote humidity sensor (opt.)
24 Vac Com.
24 VacHot
HUMRHUM
HUM
0-10
C
DI1 OSHS
CR
DEH
Scom
DEH
24 Vac Com.
On/Off Dehumidification
On/Off Dehumidification
DEH
HL
Supply Humidity High Limit Sensor (opt.)
Outside air temperaturesensor (opt.)
Sensor(s) andBI inputcommon
On/Off Dehumidification
On/Off Dehumidification
DEH
VH7270F1000 Analog
VH7270D1000 Analog
Analog 0-10 Vdc Humidification
Digital input, dry contact to "Scom"
Remote humidity sensor (opt.)
24 VacHot
On/Off Humidification
On/Off Humidification
VH7200A1000 On/Off
Digital input, dry contact to "Scom"
Optional remotehumidity sensor
HUM
0-10
HUMHUM
DI1
R C
DI1
HS
HS
Scom
OS
DEH DEH
Scom
OS
HL
Supply Humidity High Limit Sensor (opt.)
Outside air temperaturesensor (opt.)
Sensor(s) andBI inputcommon
24 Vac Com.
On/Off Dehumidification
On/Off Dehumidification
Outside air temperaturesensor (opt.)
Sensor(s) andBI input common
g.9–
p
Remote humidity sensor accessories
Model number Description:
VH2020W1000
VH2020D10000
S2000D1000
S2020E1000
S1010E1000
VH2020W1000, remote wall mounted room humidity sensor.
(see Fig.8) (wiring diagram next page)
VH2020D1000, remote duct mounted humidity sensor c/w junction box.
(see Fig.9) (wiring diagram next page)
This sensor can be used for:
• Remote return air humidity sensing with the sensor mounted on the
return air duct.
• Supply air humidity sensor used as a high limit protection.
S2020E1000, commercial style outside air temperature sensor in a
NEMA 4 enclosure. (see Fig.10) (wiring diagram next page)
S1010E1000, residential style outside air temperature sensor, capsule
type. (see Fig.11) (wiring diagram next page)
• These sensors are used for the humidity setpoint reset function
based on outdoor temperature.
INSTALLATION NOTICE !
• If replacing an old humidistat, label the wires
• Electronic controls are static sensitive devices.
• Short circuit or wrong wiring may permanently
• Anti-short cycling can be set to 0 minutes for
•
Wall mounted humidity transmitter 2% R.H.
Duct mounted humidity sensor 2% R.H.
Duct mounted outside air temperature sensor
Outside air temperature sensor in a NEMA 4 enclosure
Outside air temperature sensor, capsule type ( ¼” dia., 1” long )
before removal of the old humidistat.
Discharge yourself properly before manipulation
and installing the humidistat.
damage the humidistat or the equipment.
equipment that posses their own anti cycling
timer. Do not use that value unless the
equipment is equipped with such internal timer.
Failure to do so can damage the equipment.
All VH7200 series humidistat are to be used only as
operating controls. Whenever a control failure could
lead to personal injury and/or loss of property, it
becomes the responsibility of
the user to add safety
devices and/or alarm system to protect against such
catastro
hic fa
ilures.
Fig.10 – VH2020D1000 / S2000D1000
VH2020W1000
Fi
Fig.11 – S2020E1000
Fig.12 – S1010E1000
5
Wiring of humidity and temperature sensors
Wiring example of the High-Limit humidity sensor
powered by the same transformer as the VH7200 humidistat
VH7200 SER IES
HUMIDITY
CONTROLLER
C
RC
HL
6
VH20 SERIES
HUMIDITY TRANSMTTERS
OS
S
COM
HS
BLACK (1)
RED (2)
ORANGE (3)
COMMON
POWER
0-10 Vdc
Wiring example of the main remote humidity sensor
powered by the same transformer as the VH7200 humidistat
VH7200 SERIES
HUMIDITY
CONTROLLER
C
R
HL
OS
S
COM
HS
VH20 SERIES
HUMIDITY TRANSMTTERS
BLACK (1)
RED (2)
ORANGE (3)
COMMON
POWER
0-10 Vdc
Wiring example of the outside air temperature sensor
VH7200 SERIES
HUMIDITY
CONTROLLE R
OS
S
COM
S2020E1000 o r S1 010E1000
TEMPERATURE SENSOR
OUTSIDE AIR
Programming and status display instructions
Status display
The Humidistat features a two-line, eight-character display. There is a low level back-light level that is always
active and can only be seen at night.
When left unattended, the Humidistat has an auto scrolling display that shows the actual status of the system.
There is an option in the configuration menu to lockout the scrolling display and to only present the room humidity
and conditional outdoor humidity to the user. With this option enabled, no local status is given of mode, schedule
and relative humidity.
Each item is scrolled one by one with the back lighting off. Pressing any key will cause the back light to come on.
When left unattended for 10 seconds after changes are made, the display will resume automatic status display
scrolling.
To turn on the back light, press any key on the front panel. The back lit display will turn off when the humidistat is
left unattended for 45 seconds.
Sequence of auto-scroll status display:
Humidity Effective RH Setpoint System Mode Outdoor Temperature Alarms
Humidity RH reset Sys mode Outdoor Service
xx %RH xx %RH off x.x °C or°F
Sys mode
auto
Sys mode
Humid
Sys mode
Dehumid
Canister
Humidity
Displayed value is either the internal humidity sensor or will automatically switch to display the value of a remote
sensor if one is connected on terminal HS
Effective RH Setpoint
This conditional display prompt will show the actual reset value of the humidification setpoint if:
• The humidistat is not in dehumidification
• The outdoor temperature sensor is connected
• The outdoor temperature humidification setpoint reset function is used
• The outdoor temperature value is below the reset RH higher outside humidity setpoint
parameter
System Mode
Displayed and available system modes are dependent on the configured sequence of operation parameter.
Selected sequence of operation Modes available
0 = Ahu
1 = 2Phu
2 = 2Pdh
3 = Ahu 2Pdh
4 = 2Phu2Pdh
0-10V Analog humidification only Off - Humid Humid
2 position On-Off humidification Off - Humid Humid
2 position On-Off dehumid only Off - Dehumid Dehumid
Analog humidification & 2 position On-Off dehumidification Off – Humid – Dehumid - Auto Auto
2 position On-Off humidification & 2 position On-Off
dehumidification
Off – Humid – Dehumid - Auto Auto
Outdoor Temperature
Is displayed only when an outdoor temperature sensor is connected or a valid network value is received.
Alarms
This conditional prompt will display alarms when they are detected
• Alarms will automatically be displayed at the end of the status display scroll.
• During an alarm message display, the back lit screen will light up at the same time as the message and shut
off during the rest of the status display scroll.
• Two alarms maximum can appear at any given time. The priority for the alarms is as follows:
Service
Canister
Indicates that there is a service alarm as per one of the programmable binary input ( BI)
Indicates that the canister is dirty as per one of the programmable binary input ( BI)
7
Default
mode
8
Two status LED’s on the humidistat cover are used to indicate if Humidification or Dehumidification is active.
• When Humidity output is active the “Hum” LED will luminate.
• When Dehumidification sequence is active, the “Dehum” LED will luminate.
Installer configuration parameter menu
Fig.13 – User interface
Configuration can be done through the network or locally at the Humidistat.
• To enter configuration, press and hold the Mode button for 8 seconds
• Press again the mode button repetitively to scroll between all the available parameters
• Use the up and down key to change the parameter to the desired value.
• To acknowledge and save the new value, press the mode button again.
• The next listed parameter is now displayed
Configuration interface
Mode
Enters the configuration mode. Press and hold for 8 seconds
Pressing repetitively will scroll all available parameters one by one. Concurrently, the mode button
is used to toggle between Humidify and dehumify set points
Down
Up
User interface:
Adjust / rotate parameter value down
Adjust / rotate parameter value up
The user may choose to scroll between mode of the humidistat. By depressing on the mode button the user may
manually toggle between the following modes of operation;
Off
Auto
Humidification
Dehumidification
Keypad interface:
System is disabled
System will satisfy both Humidification and Dehumidification setpoints
System will satisfy the Humidification setpoint only
System will satisfy Dehumidification setpoint only
The user may choose to scroll between mode of the humidistat. By depressing on the mode
Mode
button the user may manually toggle between the following modes of operation; While making
changes to setpoints in “Auto Mode” the mode button is utilized to toggle between humidify and
dehumidify setpoints
Adjust the setpoints down
Down
In Humidification mode only the humidification setpoint is displayed,
In Dehumidifcation mode only the Dehumidification setpoint displayed
In auto mode, (See below)
Adjust the setpoints up
Up
In Humidification mode only the humidification setpoint is displayed,
In Dehumidifcation mode only the Dehumidification setpoint displayed
In auto mode, (See below)
1. Lockouts of access to certain functions is made with configuration parameter (lockout)
2. If the supply humidity sensor is used, press both the mode button and the up arrow button simultaneously to
momentarily display the supply humidity
High limit display:
Valid only if a high limit 0 to 10 Vdc humidity sensor is used and wired at terminal ( HL ). The actual value “Duct
HL” read by the sensor can be displayed by pressing both the mode and down arrow button simultaneously for a
few seconds.
Set point Adjustments
Humidification
Mode
Dehumidification
Mode
Off Mode Auto Mode
• Set point presented to user is the set point
from the last action taken by the humidistat
or the one currently in use.
• Humidify and Dehumify set points are
changed independently by using the toggle
function associated with the mode button.
Hum XX % and Dehum XX %
Both Hum and Dehum set point are changed
independently utilizing the mode button to
toggle between the two. A fixed dead band of
5% RH is present.
HumXX % Dehum XX %
Acess to setpoint
adjusment
Installer configuration parameter menu
Configuration can be done through the network or locally at the humidistat.
• To enter configuration, press and hold the mode button for 8 seconds
• Press the same mode button repetitively to scroll between all the available parameters
• Use the up and down key to change the parameter to the desired value.
• To acknowledge and save the new value, press the mode button again.
• The next listed parameter is now displayed
Config.
parameters
Com Addr
PAN ID
Significance
Default value
Humidistat networking
address
Default value = 4
Range is: 0 to 254
Personal Area Network
Identification
Default value = 0
Range is: 0 to 500
Adjustments
Conditional parameter to BACnet MS-TP models (VH72xxX1000B)
Conditional parameter to Wireless models (VH72xxX1000W)
This parameter will only appear when a BACnet or wireless network adapter
is present. If the humidistat is installed as a stand-alone unit or with an
Echelon adapter, this parameter will not be used or displayed
• For BACnet MS-TP models valid range to use is from 1 to 127
• For wireless models valid range is 0 to 254 with a maximum of 30
thermostat per VGG
Conditional parameter to Wireless models (VH720xxX1000W)
This parameter will only appear when a wireless network adapter is present. If
the humidistat is installed as a stand-alone unit or with a BACnet or Echelon
adapter, this parameter will not be used or displayed
This parameter (Personal Area Network Identification) is used to link specific
humidistat to a single specific Viconics wireless gateway ( VWG ) For every
humidistat reporting to a gateway ( maximum of 30 device per gateway ), be
sure you set the SAME PAN ID value both at the gateway and the
humidistat(s).
9
Channel
Channel selection
Default value = 10
Range is: 10 to 26
The default value of 0 is NOT a valid PAN ID. The valid range of available
PAN ID is from 1 to 500
Conditional parameter to Wireless models (VT720xx0X1000W)
This parameter will only appear when a wireless network adapter is present. If
the humidistat is installed as a stand-alone unit or with a BACnet or Echelon
adapter, this parameter will not be used or displayed
This parameter (Channel) is used to link specific humidistat to specific
Viconics wireless gateway(s) ( VWG ) For every humidistat reporting to a
gateway ( maximum of 30 device per gateway ), be sure you set the SAME
channel value both at the gateway and the thermostat(s).
Viconics recommends using only the 2 last channels ( 25-2575MHz and 26-2580MHz )
The default value of 10 is NOT a valid channel. The valid range of available
channel is from 11 to 26
Config.
parameters
Significance
Default value
Get From Get From Reference
address
Default value=255
BI 1
Binary input no.1
configuration
Default value = None
Lockout
Keypad lockout levels
Default value = 0 No lock
Sys Mode Setpoints
0
1
Yes access Yes access
No access No Access
SeqOpera Sequence of operation
Default value is = 2
2 position On-Off
dehumid
Units
Sets the display scale of
the thermostat
Default value = °F
Humi max Maximum humidify set
point limit
Default value = 90 %
Dehu min Minimum dehumidify set
point limit
Default value = 15%
MenuScro
Menu Scroll
Default value = On
10
Adjustments
Conditional parameter to Wireless models (VH72xxX1000W)
This parameter / function is not currently supported by the wireless humidistat
None, No function will be associated with the input
Canister, a back-lit flashing Canister alarm will be displayed on the humidistat
LCD screen when the input is energized
Service, a back-lit flashing Service alarm will be displayed on the humidistat
LCD screen when the input is energized
• Open contact input = function not energized
• Closed contact input = function energized
0 = No lock
1 = Low level lock
Level
Sets the desired control operation of the humidistat
Available sequence of operation is dependent on humidistat model
0 = Ahu - 0-10V Analog humidification only
1 = 2Phu - 2 position On-Off humidification
2 = 2Pdh - 2 position On-Off dehumid only
3 = Ahu 2Pdh - Analog humidification & 2 position On-Off dehumidification
4 = 2Phu2Pdh - On-Off humidification & 2 position On-Off dehumidification
°F for Fahrenheit scale
°C for Celsius scale
Maximum humidity set point adjustment. Humidity set point range is:
10% to 90 %
Minimum Dehumidification set point adjustment. Cooling setpoint range is:
15% to 95%
This parameter allow the user to select from scrolling system mode, room
humidity level. Disabling the scrolling function will render the display with the
Room humidity only.
Hum cph On/Off humidification
devices cycles per hour
setting:
Default value = 4 C.P.H.
Dhu cph On/Off dehumidification
devices cycles per hour
setting:
Default value = 4 C.P.H.
hum lock Humidification outside air
temperature lockout
Default value = 120 °F ( 49
°C )
Will set the maximum number cycles per hour under normal control operation
for the relay humidification output. It represents the maximum number of cycles
that the equipment will turn ON and OFF in one hour.
Note that a higher C.P.H will represent a higher accuracy of control at the
expense of wearing mechanical components faster. 3, 4, 5, 6,7 & 8 C.P.H.
Will set the maximum number cycles per hour under normal control operation
for the relay dehumidification output. It represents the maximum number of
cycles that the equipment will turn ON and OFF in one hour.
Note that a higher C.P.H will represent a higher accuracy of control at the
expense of wearing mechanical components faster. 3, 4, 5, 6,7 & 8 C.P.H.
Disables Humidification operation based on outdoor air humidity.
Function will only be enabled if OS (outside air humidity sensor) is connected.
From -15 °F up to 120 °F ( -26 °C up to 49 °C )
11
Config.
parameters
Dhu OALK Dehumidification outside air
HL Hyst High Limit hysterisys
cal RH Humidity sensor calibration
cal OS Outside air temperature
sensor calibration
Default value = 0.0 °F or °C
RH LT
RH HT Reset RH higher outside
RE Sp Reset humidity setpoint
HL Sp RH High limit setpoint
Significance
Default value
temperature lockout
Default value = -40°F (-
40°C)
Default value = 5% RH
Default value = 0 %RH
Reset RH lower outside
temperature setpoint
Default value = -20°F (-
29°C)
humidity setpoint
Default value = 32°F (0°C)
Default value = 20% RH
Default value = 85% RH
Adjustments
Outside air temperature under which the dehumidification sequence is
disabled.
Only valid if an outdoor air sensor is connected at the humidistat or a network
value is transmitted to the humidistat.
From –40°F up to 122°F (-40°C to 50°C)
High Limit control hysterisys.
Used only if sequence uses 2 position humidity controle
2 = 2Pdh and 4 = 2Phu2Pdh
From 2% RH up to 20% RH
Offset that can be added/subtracted to actual displayed humidity by ± 15.0
%RH.
This calibration applies to the internal humidity sensor if no remote humidity
sensor is connected. This calibration applies to the remote humidity sensor
when one is connected.
From –15% RH up to 15% RH
Offset that can be added/subtracted to the displayed outside air temperature
± 5.0 °F ( ± 2.5 °C )
Minimum outside air temperature for RH setpoint reset.
Only valid if an outdoor air sensor is connected at the humidistat or a network
value is transmitted to the humidistat. See RH HT & RE Sp.
From –40°F up to 15°F (-40°C to –9.5°C)
Maximum outdoor air temperature for RH setpoint reset.
Only valid if an outdoor air sensor is connected at the humidistat or a network
value is transmitted to the humidistat. See RH LT & RE Sp
From 20°F up to 55°F (-6.5°C to 12.5°C)
The RH setpoint will be reset from the user setpoint to this value when the RH
LT outside air humidity value is reached.
Only valid if an outdoor air sensor is connected at the humidistat or a network
value is transmitted to the humidistat. See RH LT & RE HT.
From 10% RH up to 90% RH
High humidity limit in the supply.
Only valid if a 0-5 Vdc sensor is connected at the humidistat – otherwise this
feature is disabled automatically.
From 50% RH up to 90% RH
Humidity setpoint reset by outside air temperature
If an outdoor air sensor is connected at the thermostat
45%
RH Set = 45%
or a value is received from the network, it can be used
to reset the humidity setpoint during the cold season to
40%
minimize condensation on windows and building
structures.
%RH Setpoint
35%
30%
25%
20%
RH HT = 32°F
RE Sp = 20%
RH LT = -20°F
When the outdoor temperature falls below the selected
high temperature, parameter RH HT (32°F in the
example Figure 8), the humidity setpoint will start to
decrease. The lowest humidity setpoint will be reached
at selected low temperature, parameter RH LT (-20°F).
The setpoint decrease from original setpoint to the
lowest setpoint determined by the parameter RE Sp. In
the example, Figure 8, RE Sp was set to 20%, therefore
-40°F
-20°F 0°F 20°F 40°F
Outside Air Temp.
the humidity setpoint dropped from 45% to 20%.
If you don’t want to use this feature, set the RE Sp
parameter to 90% RH.
Fig.11 – Humidity setpoint reset by outside air temperature
High limit humidity sensor (VH7270 Models Only)
The VH7270 models include a high limit sequence. This
100 %
allows the use of a remote 0 to 10 Vdc humidity sensor to
limit the humidity in the supply air. If no sensor is detected at
Control
Output
Level
50 %
0 %
85 %
Maximum Supply Humidity
the HL connector, this sequence is disabled at the
humidistat.
Note: this high limit function is not a safety device. For
critical situations, provide installation with normal protections
required to ensure a safe operation.
Fig.12 – High humidity limit vs Control output level curve
Troubleshooting guide
Symptom Possible Cause Corrective Action
Digital display
Defective display Replace humidistat
shows missing
digits or erratic
segments
12
Humidistat does
not call for
humidification.
(Hum LED is OFF)
RH sensor is out of range Verify the remote RH sensor or the internal RH sensor
System Mode in
Change the system mode parameter to Humidification
Dehumidification or Off
System Mode in Auto but there
is a Dehumidification demand
Wait: when a Humidification demand will occur at the
humidistat, humidification will resume
at the humidistat
High limit sensor is controlling
the humidifier output by forcing
Wait: when the supply humidity will drop below the high
limit setpoint, humidification will resume.
it to 0%
Humidistat calls for
humidification.
(Hum LED is ON)
but the humidifier
does not operate
Humidistat does
not call for
dehumidification
(Dehum LED is
OFF)
Humidistat calls for
dehumidification
(Dehum LED is
ON) but the
dehumidifier does
not operate
Specifications
On a VH7270F1000,
disconnect the wire on the
“Hum” terminal measure the
voltage across terminals
“Hum” and “C” you should
read a dc voltage close to 10
Volts
If the “Hum” LED is ON and you measure a dc voltage
close to 10 Vdc, the humidistat is working fine. Look at
the wiring between the Humidistat and the Humidifier. If
the Humidistat is not powered by the Humidifier
(separate transformer) you may have a conflict with the
Common (signal reference)
If the “Hum” LED is ON and you don’t measure a dc
voltage, the humidistat is probably defective, contact
your distributor or Viconics technical support
department.
On a VH7200A1000,
disconnect the wire on the
“Hum” terminal measure the
voltage across terminals
“Hum” and “C” you should
read 24 Vac.
If the “Hum” LED is ON and you measure 24 Vac, the
humidistat is working fine. Look at the wiring between
the Humidistat and the Humidifier. If the Humidistat is
not powered by the Humidifier (separate transformer)
you may have a conflict with the Common (signal
reference)
If the “Hum” LED is ON and you don’t measure 24 Vac,
the humidistat is probably defective, contact your
distributor or Viconics technical support department.
RH sensor is out of range Verify the remote humidity sensor and it’s wiring or the
internal RH sensor
System Mode in Humidification
Change the system mode parameter to Dehumidification
or Off
System Mode in Auto but there
is a Humidification demand at
Wait: when a Dehumidification demand will occur at the
humidistat, dehumidification will resume.
the humidistat
Outside air humidity is below
the Dhu OALK parameter
On all models, take a wire
(jumper) and short across
“DEH” and “DEH” terminals.
Change the Dhu OALK parameter to a value that will
enable the dehumidification, if desired.
When you short across the two “DEH” terminals the unit
does not operate, the problem is related to wiring or to
the dehumidification device. Refer to wiring diagram.
If the system turns ON when you short across the two
“DEH” terminals the humidistat dehumidification contact
is probably defective, replace humidistat.
Humidistat power requirements: 19-30 Vac 50 or 60 Hz; 2 VA ( RC & C ) Class 2
Operating conditions: 0 °C to 50 °C ( 32 °F to 122 °F )
0% to 95% R.H. non-condensing
Storage conditions: -30 °C to 50 °C ( -22 °F to 122 °F )
0% to 95% R.H. non-condensing
Resolution: Temperature: ± 0.1 °C (± 0.2 °F)
Humidity: ± 0.1%
Control accuracy: Humidity: ± 5% RH from 20 to 100% RH at 50 to 90°F (10 to 32°C)
Humidification setpoint range: 10% RH to 90% RH
Dehumidification setpoint range: 15% RH to 95% RH
Outdoor air temperature range: -40 °C to 50 °C ( -40 °F to 122 °F )
Binary inputs: Relay dry contact only across “Scom” and “DI1” terminals
Contact output rating: Each relay output: 30 Vac, 1 Amp. Max. / 30 Vac, 3 Amp. in-rush
Analog output rating
Wire gauge 18 gauge maximum, 22 gauge recommended
Dimensions: 4.94” x 3.38” x 1.13”
Approximate shipping weight: 0.75 lb ( 0.34 kg )
Agency Approvals:
Industry Canada ICES-003 (Canada)
C-Tick AS/NZS CISPR 22 Compliant (Australia / New Zealand)
0 t0 10 Vdc into 2KΩ resistance minimum
UL UL 873 (US) and CSA C22.2 No. 24 (Canada), File E27734 with CCN
XAPX (US) and XAPX7 (Canada)
FCC Compliant to CFR 47, Part 15, Subpart B, Class A (US)
CE EMC Directive 89/336/EEC (Europe Union)
13
Drawing & dimensions Important notice
verifications prior to shipment to ensure proper and
reliable operation in the field. Whenever a control
failure could lead to personal injury and/or loss of
property, it becomes the responsibility of the user /
installer / electrical system designer to incorporate
safety devices (such as relays, flow switch, thermal
protections, etc…) and/or alarm system to protect the
entire system against such catastrophic failures.
Tampering of the devices or miss application of the
device will void warranty.
All VH7200 series controls are for use
as operating controls only and are not
safety devices. These instruments have
undergone rigorous tests and
14
Fig.16 – Humidistat dimensions : VH7200A1000, VH7270F1000, VH7270K1000
Fig.17 – Humidistat dimensions : VH7270D1000
Loading...