Neptronic HRO20 User manual

Humidity Controller
Specification and Installation Instructions
HRO20-141202-ETL Page | 1
Model
HRO20
Description
The Humidity Controller is a combination controller and
humidistat. The Humidity Controller is an advanced application
to control relative humidity for general purpose applications.
They are specially designed to control humidifiers and
dehumidification equipment.
Features
Outputs & Inputs
•4 analog outputs (0-10 Vdc or 2-10 Vdc)
•2 dry contact outputs
•External humidity sensor input
•Window or external temperature sensor input
•Alarm status input
Operation & Display
•Wall mounted controller
•Adjustable setpoint with auto reset from external sensor
•Multi level lockable access menu
•Lockable setpoint and control mode
•Backlit LCD with simple icon and text driven menus
•Selectable Celsius or Fahrenheit scale
•Humidification and dehumidification indicator
HRO20
Technical Specifications
Description
HRO20
Outputs
- Actual humidity (0-100% RH), 0-10 Vdc/2-10 Vdc
- Humidity setpoint (0-100% RH), 0-10 Vdc/2-10 Vdc
- Humidification proportional control signal, 0-10 Vdc/2-10 Vdc
- Dehumidification proportional control signal, 0-10 Vdc/2-10 Vdc
- Humidification dry contracts 24 Vac, 1 A max, 3 A in-rush
- Dehumidification dry contracts 24 Vac, 1 A max, 3 A in-rush
Inputs
- Window temperature sensor or outside temperature sensor (10 K Ω)
- External setpoint from Neptronic humidifier, external humidity sensor (0-10 Vdc/2-10 Vdc) or
high limit (0-10 Vdc/2-10 Vdc)
- 1 alarm status digital input (24 Vac or dry contact)
Power supply
22 to 26 Vac 50/60 Hz or 28 to 32 Vdc
Power consumption
1 VA
Setpoint range
10%-90% RH (in 1% increments)
Sensor precision
± 3% or better at 40% RH and 23ºC [73ºF]
Proportional band
2%-10% for control signal
Electrical connection
0.8 mm2 [18 AWG] minimum
Operating condition
0ºC to 40ºC [32ºF to 104ºF], 0-95% RH
Storage condition
-10ºC to 50ºC [14ºF to 122ºF], 0-95% RH
Temperature compensation reset
Automatic readjustment of setpoint from a window temperature sensor (SHW0-11),
or external temperature sensor (STC8-11)
Housing degree of protection
IP 30 (EN 60529)
Weight
130 g. [0.3 lb]

Humidity Controller
Specification and Installation Instructions
www.neptronic.com Page | 2
Description
HRO20
Dimensions
A = 2.85” | 73mm
B = 4.85” | 123mm
C = 1.00” | 24mm
D = 2.36” | 60mm
E = 3.27” | 83mm
A
B
C
D
E
Wiring
We strongly recommend that all Neptronic products be wired to a separate grounded transformer and that transformer shall service
only Neptronic products. This precaution will prevent interference with, and/or possible damage to incompatible equipment.
For more information about wiring the humidistat with various humidifiers, refer to the Wiring - Humidistat and Humidifiers section.
TB1
1 2 3 7 8 9 10 11 12 13 14 15 16
JP3
PGM RUN
JP2
Temperature
Sensor
Mode Selector
(JP3)
A B C
A
B
C
Connector strip
(TB1)
Digital Output
Signal Selector (JP2)
Terminal Description
Details
1
Common
2 24 Vac or 30 Vdc
3
Not Used
7
Common Relay
8 Humidify Contact Output (DO1)
9
Dehumidify Contact Output (DO2)
10
Humidify setpoint analog output (AO4)
Note: If dehumidify only is selected,
AO4 = 0 V
see step 16 “min vdc analog ao4
output”
11
Alarm status digital input (DI1)
12
External setpoint from Neptronic
humidifier, or external humidity sensor
(0-10Vdc/2-10Vdc) (AI1)
see step 17 “select AI1 input
signal"
13
Window temperature sensor or
outside temperature sensor input (AI2)
see step 20 “select AI2 input
signal”
14 Humidify Analog Output (AO1) see step 13 “min vdc analog ao1
output”
15 Dehumidify Analog Output (AO2) see step 14 “min vdc analog ao2
output”
16
Actual Humidity Output (0-100% RH)
(AO3)
see step 15 “min vdc analog ao3
output”
Jumpers
Jumpers
Description
JP2
Digital Output Signal
Selector
A&B = Internal: Digital output signal is linked to internal 24 Vac (same as humidistat)
B&C = External: Digital output signal is linked to external 24 Vac (different than humidistat)
JP3
Mode Selection
A&B = RUN: Humidistat is in Operation Mode. (See Operation Mode on page 7)
B&C = PGM: Humidistat is in Programming Mode. (See Programming Mode on page 3)

Humidity Controller
Specification and Installation Instructions
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Mounting Instructions
CAUTION: Remove power to avoid a risk of malfunction.
A. Remove the captive screw that’s holding the base and the front cover of the humidistat together.
B. Lift the front cover of the humidistat to separate it from the base.
C. Pull all wires through the holes in the base.
D. Secure the base to the wall using wall anchors and screws (supplied). Make the appropriate connections.
E. Mount the control module on the base and secure using the screw.
A
E
D
C
B
Programming Mode
The Mode Selector Jumper (JP3) must be set to the "PGM" mode (Programming Mode). Refer to Wiring on page 2.
To exit, set the Jumper (JP3) back to the "RUN" mode (Operation Mode). All changes will be saved.
Symbols used in this Manual
Humidity Analog Output 1
Temperature Analog Output 2
Analog Input 1 Analog Output 3
Analog Input 2 Analog Output 4
Setpoint and User Control
1. “inside humidty sensor offset”
Range:
Offset:
Increment:
10 to 90% RH
Max. ± 5%
0.1% RH
Compare the displayed humidity reading with a known value from a humidistat. To offset or calibrate the sensor, use the arrow
keys to set the desired humidity reading. This is useful for humidistats installed in areas where the humidity read is slightly
different than the room’s actual humidity. For example, a humidistat placed right under the air diffuser.

Humidity Controller
Specification and Installation Instructions
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2. “inside temper sensor offset”
Range:
Offset:
Increment:
10 to 40ºC [50 to 104ºF]
Max. ± 5%
0.1ºC [0.2ºF]
Compare the displayed temperature reading with a known value from a thermometer. To offset or calibrate the sensor, use the
arrows key to set the desired temperature reading. This is useful for thermostats installed in areas where the temperature read
is slightly different than the room’s actual temperature. For example, a humidistat placed right under the air diffuser.
3.“adjust minimum user setpnt”
Default:
Range:
Increment:
15% RH
10 to 90% RH
1% RH
In Operation Mode, you cannot decrease the setpoint to less than the value set as the minimum humidity setpoint. The
minimum value is restricted by the maximum value set in Step 4 “adjust maximum user setpnt”. In other words, the value that is
set as the minimum cannot be greater than the maximum value.
4. “adjust maximum user setpnt”
Default:
Range:
Increment:
65% RH
10 to 90% RH
1% RH
In Operation mode, you cannot increase the setpoint to more than the value set as the maximum humidity setpoint. The
maximum value is restricted by the minimum value set in Step 3 “adjust minimum user setpnt”. In other words, the value that is
set as the maximum cannot be less than the minimum value.
5. “user setpnt locked”
Default:
Range:
No (Unlocked)
No (Unlocked), Yes (locked)
If set to No, the user setpoint option is not locked and the user can adjust the desired humidity setpoint. If set to Yes, the user
setpoint option is locked and the user cannot set the desired humidity setpoint. A lock symbol appears to indicate that the
setpoint is locked.
Humidity Settings
6. “adjust control mode”
Default:
Range:
Hu (humidify only)
Hu (humidify only), AuTo (Automatic humidify and dehumidify), dEHU (dehumidify only)
Select the control mode that you want to authorize to the user. To authorize all the available modes, select AuTo(Automatic
Mode).
If you selected dEHu at this step, go to Step 8 “adjust dehumi setpnt”.
7.“adjust humidty setpnt”
Default:
Range:
Increment:
40% RH
10 to 90% RH
1% RH
Set the desired humidity setpoint within the defined range. If the setpoint option was locked at Step 5 “user setpnt locked”, a
lock symbol is displayed. The setpoint value is restricted by the minimum (Step 3 “adjust minimum user setpnt”) and
maximum (Step 4 “adjust maximum user setpnt”) values. In other words, the setpoint should be within the minimum and
maximum setpoint range.
If you selected Hu at Step 6 “adjust control mode”, go to Step 9 “enable on off control mode”.
8. “adjust dehumi setpnt”
Default:
Range:
Increment:
50% RH
10 to 90% RH
1% RH
Set the desired dehumidify setpoint within the defined range. If the setpoint option was locked at Step 5 “user setpnt locked”, a
lock symbol is displayed. The setpoint value is restricted by the minimum (Step 3 “adjust minimum user setpnt”) and
maximum (Step 4 “adjust maximum user setpnt”) values. In other words, the setpoint should be within the minimum and
maximum setpoint range.

Humidity Controller
Specification and Installation Instructions
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9. “enable on off control mode”
Default:
Range:
Yes (Enable)
Yes (Enable), No (Disable)
If you select Yes, the user can set the unit to Off via the Control Mode. If you select No, the Off selection does not appear in
the Control Mode.
If you have selected dEHU at Step 6 “adjust control mode”, go to Step 11 “dehumi control ramp”.
10. “humidty control ramp”
Default:
Range:
Increment:
5.0% RH
2 to 10% RH
0.5% RH
Select the desired span for the humidify ramp. The humidify symbol is also displayed.
If you selected Hu at Step 6 “adjust control mode”, go to Step 12 “control dead band”.
11. “dehumi control ramp”
Default:
Range:
Increment:
5.0% RH
2 to 10% RH
0.5% RH
Select the desired span for the dehumidify ramp. The dehumidify symbol is also displayed.
12. “control dead band”
Default:
Range:
Increment:
0.3% RH
0.3 to 5.0% RH
0.1% RH
Select the desired dead band value. The humidify and dehumidify symbols are also displayed.
If you selected dEHU at Step 6 “adjust control mode”, go to Step 14 “min vdc analog ao2 output”.
Analog Outputs (AO1 to AO4)
13. “min vdc analog ao1 output”
Default:
Range:
0.0 Volt
0.0 or 2.0 Volt
Select the desired value of the minimum voltage of AO1 output. The humidify symbol is also displayed.
If you selected Hu at Step 6 “adjust control mode”, go to Step 15 “min vdc analog ao3 output”.
14. “min vdc analog ao2 output”
Default:
Range:
0.0 Volt
0.0, 2.0 Volt
Select the desired value of the minimum voltage of AO2 output. The dehumidify symbol is displayed.
15. “min vdc analog ao3 output”
Default:
Range:
0.0 Volt
0.0, 2.0 Volt
Select the desired value of the minimum voltage of AO3 output. The humidify symbol is also displayed.
If you selected dEHU at Step 6 “adjust control mode”, go to Step 17 “select AI1 input signal".
16. “min vdc analog ao4 output”
Default:
Range:
0.0 Volt
0.0, 2.0 Volt
Select the desired value of the minimum voltage of AO4 output. The humidify symbol is also displayed.

Humidity Controller
Specification and Installation Instructions
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Analog Inputs (AI1 and AI2)
17. “select AI1 input signal"
Default:
Range:
OFF (input not used)
OFF, EHS.0, EHS.2, SPS, HIL.0, HIL.2
Select the input signal type for AI1 (analog input 1).
•If SPS is selected, the humidify setpoint will be disabled.
If you selected OFF or SPS, go to Step 20 “select AI2 input signal” .
Input not used
External Humidity
Sensor 0-10 Vdc
External Humidity
Sensor 2-10 Vdc
External Setpoint from
Neptronic Humidifier
High Limit 0-10 Vdc
High Limit 2-10 Vdc
18. “extern humidty sensor offset”
Range:
Offset:
Increment:
10 to 90% RH
Max. ± 5%
0.1% RH
This option appears if you have selected EHS.0, EHS.2, HIL.0, or HIL.2 at Step 17 “select AI1 input signal". When the
humidistat is connected to the appropriate analog input (AI1 or AI2), the display shows the relative humidity percentage read by
the external humidity sensor. Adjust the offset by comparing it with a known value humidistat. If the sensor is not connected or
short circuited, the display is blank, “Error“. The humidify symbol is also displayed.
19. “adjust setpnt high limit”
Default:
Range:
Increment:
80% RH
10 to 90% RH
1% RH
This option appears if you have selected HIL.0 or HIL.2 at Step 17 “select AI1 input signal". Select the desired high limit
humidity setpoint. The value should be within the high limit range.
20. “select AI2 input signal”
Default:
Range:
OFF (input not used)
OFF, Wts, OtS
Select the input signal type for AI2 (analog input 2).
If you selected OFF, go to Step 1 “inside humidty sensor offset”.
Input not used Window Temperature
Sensor 10KΩ
Outside Temperature
Sensor 10KΩ
21. “extern temper sensor offset”
Range:
Offset:
Increment:
-30 to 90ºC [-22to 194ºF]
Max. ± 5%
0.1ºC [0.2ºF]
This option appears if you have selected WtS or EtS at Step 20 “select AI2 input signal”. The display shows the temperature
read by the external temperature sensor. Adjust the offset by comparing it with a known value (e.g. thermometer). If the sensor
is not connected or short circuited, the display is blank, “Error“.
.

Humidity Controller
Specification and Installation Instructions
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22. “window temper sensor compens”
Default:
Range:
Increment:
80
25 to 90
5
This option appears if you have selected WtS at Step 20 “select AI2 input signal” . Adjust the compensation factor value to
avoid condensation on the window. The lower the compensation factor value, the lower the maximum humidity setpoint can be
adjusted.
Operation Mode
The Mode Selector Jumper (JP3) must be set to the "RUN" mode (Operation Mode). Refer to Wiring on page 2.
Power Up
Upon power up, the LCD illuminates and all segments appear for 2 seconds. The humidistat then displays its current version for 2
seconds.
LCD Backlight
Pressing any key on the humidistat illuminates the LCD for 4 seconds.
Humidity
The humidistat always displays the humidity reading. If the sensor is disconnected or short circuited, then “OFF”, “- - -”, and alarm
symbol are displayed. Available only if the humidifier alarm output (NO) is connected to the humidistat.
Temperature
To display the temperature, press the key. The temperature reading is displayed for 2 seconds. If the sensor is disconnected or
short circuited, then “- - -” is displayed. To toggle the temperature scale between ºC and ºF, press both and keys for 3
seconds.

Humidity Controller
Specification and Installation Instructions
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Humidity Setpoint Adjustment Mode
To access the Humidity setpoint, press both the and keys twice. The humidity setpoint will be displayed for 3 seconds. To
adjust the setpoint, press the and keys while the setpoint is displayed. If the setpoint adjustment has been locked at Step 5
“user setpnt locked”, the lock symbol appears.
If the Control Mode option was set to Hu or dEHU at Step 6 “adjust control mode”, either the Humidify or Dehumidify setpoint will be
displayed. If the Control Mode option was set to AuTo at Step 6 “adjust control mode”, the Humidify setpoint will be displayed. To
switch between humidify and dehumidify setpoint, press .
The humidistat will return to normal mode if you navigate through the entire menu and do not make any selection, or if you do not
press any key for 3 seconds. The changed values will be saved automatically.
Control Mode
To access the Control Mode, press the key. The Control Mode appears for 5 seconds. The following options are available:
•Humidify only/OFF
•Dehumidify only/OFF
•Automatic Humidify and Dehumidify/OFF
These options can vary according to the choice made in Step 6 “adjust control mode” of the Programming Mode.

Humidity Controller
Specification and Installation Instructions
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Wiring - Humidistat and Humidifiers
SK300 Humidifier
humidistat
24 VAC
Pressure Differential
switch
High limit
1 432F
875 6 9
Control terminal
block wiring
Low voltage control
terminal block
High voltage power
terminal block
L1 L2 L3
F
5
4321
98
6 7
5 Vdc
HRO20
16
14 15 1312
MOD
Set point
%RH
COM
SK300 BACnet Humidifier
Control terminal
block wiring
Low voltage control
terminal block
High voltage power
terminal block
Pressure differential
switch
High limit
humidistat
L1 L2 L3
F
5
4321
98
6 7
1432F
875 6 9 Interlock *
humidistat
HRO20
16
14 15 1312
COM 24 VAC
%RH
MOD

Humidity Controller
Specification and Installation Instructions
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SKS Humidifier
Hi-Limit
humidistat
Fan Proof
24 VAC
Interlock
116
54321 7 8 910
Common
12 13
Fan &
alarms
contacts
Control demand
Room humidistat
humidistat
HRO20
16
14 15 1312
COM 24 VAC
%RH
MOD
SKG Humidifier
Common
24 VAC
%RH
Control Signal
1 32 4 5 6 7 8 9
1 2 3 4 5 6
1 2 3
R-
R+
LAST
ANLG OUT
12 3 4 5
X
6789
DUCT
HUMID.
ROOM
HUMID.
CTRL
DEMAND
INTER
LOCK
PD
SWITCH
HI-LIM
24 VAC
700MA
MAX.
TB1
TB2
JP2 JP1
DS1
O
N
P1
RS-232
A+B-
TB3
RS-485
COM NO NC COM NO NC
ALARM FAN
To be wired if you intend to control Humidifer from HRO20
(Mode External in Control Setup menu - Display #200)
HI LEVEL HUMIDISTAT
P. D. SWITCH
OTHER INTERLOCK
1614 151312
HRO20
humidistat

Humidity Controller
Specification and Installation Instructions
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SKR Humidifier
On/Off Push button Drain Push button
Drain LED (Yellow)
Fan LED (Green)
Access panel
Alarm LED (Red)
Power LED (Green)
Fill LED (Yellow) Steam LED (Green)
SKR Printed circuit board
Dip switches
TB5
External
cut-off
24 Vdc
TB6
ON
1 2 3 4
Transformer
Control demand from
humidistat 0-10 Vdc
-
+
External transformer
(by others)
1 2
12 13 14 15 16
COM
24VAC
MOD
HRO20
humidistat

Humidity Controller
Specification and Installation Instructions
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Notes
Recycling at end of life: please return this product to your Neptronic local distributor for recycling. If you need to find the nearest
Neptronic authorized distributor, please consult www.neptronic.com.
400 Lebeau blvd, Montreal, Qc, H4N 1R6, Canada
www.neptronic.com
Toll free in North America: 1-800-361-2308
Tel.: [phone]
Fax: [phone]
Customer service fax: [phone]
Monday to Friday: 8:00am to 5:00pm (Eastern time)