DriSteem D77 User manual

MODEL D77
Controller
DEHUMIDIFIER CONTROL
Installation, Operation, and
Maintenance Manual
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Table of contents
SPECIFICATIONS .............................................................4
Overview and specifications.................................4
Mount control ...........................................5
INSTALLATION ..............................................................5
OPERATION ...............................................................10
System checkout ........................................10
Error Codes ...........................................13
TROUBLESHOOTING.........................................................13
Model D77 troubleshooting guide ............................14
RL-31 dehumidifier diagnostic codes ..........................15
WARRANTY ...............................................................19
2D77 CONTROLLER INSTALLATION, OPERATION, AND MAINTENANCE MANUAL

Warnings and cautions
CAUTION
1. Read all instructions before beginning installation.
2. Do not use in pool applications. Pool chemicals can damage the control.
3. Do not use solvents or cleaners on or near the display and circuit board.
Chemicals can damage components.
WARNING
1. Improper installation may cause property damage or injury. Installation,
service, and maintenance must be performed by a qualified service
technician.
2. Line voltage may cause serious injury from electric shock. Disconnect
electrical power before starting installation or servicing. Leave power
disconnected until installation/service is completed. This control is not a
120 Volt (line voltage) device.
WARNINGS
Fill in the following information for your records
Date of purchase ______________________________________________________________
Customer's name ______________________________________________________________
Model number ______________________________________________________________
Serial number ______________________________________________________________
3
D77 CONTROLLER INSTALLATION, OPERATION, AND MAINTENANCE MANUAL

SPECIFICATIONS
Table 4-1: D77 controller specifications
Electrical
Input Voltage: 24VAC +/-20%
Current: 25mA (nominal), 50mA (max.) at 24VAC
Output Dry Contact, Normally Open
Control
Control Range 35% – 80% RH
Accuracy +/-5% RH
Differential 3%
Low Limit 40°F (4°C) Dew Point
High Limit 99°F (37°C) Dry Bulb
OVERVIEW
The control allows the user to set and adjust the humidity setting and turn
dehumidification on or off from a convenient location. In this application, the
Model D77 uses an onboard sensor to monitor the relative humidity (%RH) in
the space in which it is located and displays the measured relative humidity on
the digital display.
Overview and specifications
4D77 CONTROLLER INSTALLATION, OPERATION, AND MAINTENANCE MANUAL

5
FEET
NONO
18"
MINIMUM
NO
90-1640
Mount control
• In the area where moisture levels need to be monitored and controlled.
• On an interior wall.
• At least 18” from an outside wall.
DO NOT MOUNT CONTROL
• In the flow of a supply register.
• Behind doors, in corners or other dead air spaces.
• In direct sunlight, near lighting fixtures, or other appliances that give off
heat.
• On an outside or unconditioned area wall.
• In stairwells or near outside doors.
• On a wall with concealed pipes or ductwork.
INSTALLATION
FIGURE 5-1: MOUNTING LOCATION
5
D77 CONTROLLER INSTALLATION, OPERATION, AND MAINTENANCE MANUAL

PULL APART
BACK PLATE
FRONT COVER
ANCHOR
BACK PLATE
SCREW
90-2504
90-2485
Mount control
FIGURE 6-1: DISASSEMBLE CONTROL
FIGURE 6-2: MOUNT BACK PLATE
INSTALLATION
6D77 CONTROLLER INSTALLATION, OPERATION, AND MAINTENANCE MANUAL

INSTALLATION
• 18-22 gauge wire (field supplied), 4 wires required, run new cable as
needed.
• (2) #8 x 1-1/2" mounting screws (supplied)
• (2) Anchors (supplied)
1. Level the back plate on the wall and mark the mounting holes and wire
access location on the wall.
2. Drill two 3/16" mounting holes and a 3/4" wire access hole. See Figure
6.
3. Install the drywall anchors flush with the wall surface.
Note: Mounting holes on the back plate are designed to fit on a horizontal
J-box.
4. Run a 4-wire cable from the dehumidifier to the wall mount location and
through the square hole in the back plate.
5. Secure the back plate to the wall using the two #8 x 1-1/2" screws.
Required components
7
D77 CONTROLLER INSTALLATION, OPERATION, AND MAINTENANCE MANUAL

+ - A B ODT
SensorRemote
Gh Rf Cf Gs YW
HVAC EQUIP.
MODEL D77
CONTROL
DH
DH
R/+
C/-
B
A
90-2490
1. Disconnect power to the dehumidifier and HVAC system.
2. Remove the wiring access cover next to the control on the dehumidifier.
3. Wire the Model D77 to the dehumidifier as shown in Figure 8-1.
FIGURE 8-1: MODEL D77 WIRING WITH DRISTEEM DEHUMIDIFIERS
Wiring D77 with DriSteem dehumidifiers
INSTALLATION
8D77 CONTROLLER INSTALLATION, OPERATION, AND MAINTENANCE MANUAL

Wiring D77 with Dristeem Dehumidifiers
4. Snap the wiring access cover
back into place, power up the
dehumidifier and use the ON/
OFF button to turn the unit OFF (if
ON). See Figure 9-1.
5. Press and hold the MODE button
for 3 seconds to enter the Installer
Set Up menu. REMOTE DISABLED
will appear on the display when
Installer Set Up is entered.
6. Press the or button to
change to REMOTE ENABLED.
7. Repeatedly press the MODE
button until DONE appears on
the display.
FIGURE 9-1:
90-1854
FIGURE 9-2:
90-1854
INSTALLATION
9
D77 CONTROLLER INSTALLATION, OPERATION, AND MAINTENANCE MANUAL

90-2483
90-1636
Model D77 Control
Model D77 LCD Display
Blinking ON + *: Control Limit
Exceeded.
See Control Limits, page 11.
Solid ON:
Control On
Blinking ON:
Dehumidifying
Measured
Humidity or
Setting Control On/Off
Humidity Setting and
Offset Adjustment
Control must be ON
to adjust offset and
setting.
SET: Shows when
humidity setting
displayed or
being changed.
OFF: Control Off
FIGURE 10-1: EXTERNAL CONTROL
System checkout
POWER UP
1. Check all wiring.
2. Plug in dehumidifier and restore power to the HVAC system.
3. Turn on/off switch on dehumidifier ON. After a 4 second start up
sequence all buttons on the Model D77 will be functional.
• The control will be OFF.
• The humidity setting will be 60%.
• The control will display the measured humidity.
OPERATION
10 D77 CONTROLLER INSTALLATION, OPERATION, AND MAINTENANCE MANUAL

90-1636
OPERATION
FIGURE 11-1:
TEST MODE
1. Press and hold the ON button for 5 seconds to enter Test Mode.
a. Verify the measured humidity is displayed on the Model D77 screen.
b. Verify ON blinks on the Model D77 screen.
2. After 5 minutes or after pressing the OFF button, the control will enter Off
mode.
a. Verify the dehumidifier turns off.
HUMIDITY SETTING
• The control must be ON to adjust the humidity setting.
• The (up) and (down) buttons are used to increase or decrease the
setting.
• The first press of either button will display the current setting and SET on the
LCD display.
• Each subsequent push of the or button will change the setting by
1% RH.
• If a button is held down, the setting will continually change by 1% every
1/2 second for as long as the button is pressed.
• The control will return to Normal Mode, displaying the measured humidity,
5 seconds after the last button press/release.
OFFSET
An offset can be applied to the humidity
reading to avoid discrepancies with
other humidity measuring devices. Allow
48 hours for the control to acclimate
before applying an offset. The control
must be ON to enter the Offset screen.
• Press and hold the OFF button for 5
seconds to enter the Offset screen.
• The buttons can be used to
set an offset value between -5% RH
and +5% RH.
• The control will return to Normal
Mode, displaying the measured
humidity, 5 seconds after the last
button press/release.
System checkout
11
D77 CONTROLLER INSTALLATION, OPERATION, AND MAINTENANCE MANUAL

OPERATION
TURING ON AND SETTING THE CONTROL
1. Press the ON button on the dehumidifier user interface and on the Model
D77 control.
2. Use the buttons to set the control at the desired humidity level.
Increasing the humidity setting will decrease dehumidifier run
time, allowing for higher humidity levels.
Decreasing the humidity setting will increase dehumidifier run
time, allowing for lower humidity levels.
SEQUENCE OF OPERATION
NORMAL MODE
• When the measured humidity is greater than the setting, the control will
activate the dehumidifier output, the dehumidifier will begin dehumidifying
and ON will blink on the LCD display.
• When the measured humidity falls 3% below the setting, the control will
deactivate the dehumidifier output, the dehumidifier will stop dehumidifying
and the LCD will display a solid ON.
CONTROL LIMITS
• If the control measures a dew point below 40°F (4°C) OR a temperature
above 99°F (37°C), the control will deactivate the dehumidifier output if
actively dehumidifying, the dehumidifier will stop dehumidifying, and ON
and *will blink on the LCD screen.
• The control will resume normal operation when the measured dew point
is greater than 45°F (7°C) or the measured temperature is below 94°F
(34°C), whichever control limit was exceeded.
System checkout
12 D77 CONTROLLER INSTALLATION, OPERATION, AND MAINTENANCE MANUAL

90-1636
TROUBLESHOOTING
Error Codes
Use the guide on the following page
to help find and correct system
faults. Contact Technical Support
before replacing the control or for
additional troubleshooting. Technical
Support is available Monday through
Friday, 7:00 a.m. to 5:00 p.m. CST,
at [phone].
When the control detects an
internal error, it will stop controlling,
deactivate the dehumidifier output,
and the LCD will display the Error
Code. See Figure 13-1. The
control will attempt to recover from
the error every 10 minutes. The Error
Code will continue to be displayed
as long as the error condition exists.
Button presses are not registered
when in Error Mode. Cycling power
to the control will not clear the code
and the control will need to be
replaced.
DEHUMIDIFIER DIAGNOSTIC CODES
When a dehumidifier error occurs,
the diagnostic code will be displayed
on the D77 screen.
FIGURE 13-1: ERROR CODE SCREEN
13
D77 CONTROLLER INSTALLATION, OPERATION, AND MAINTENANCE MANUAL

Table 14-1: D77 Troubleshooting Guide
Symptom Possible Reason Troubleshooting Procedure
No power to
the control.
Incorrect wiring. Verify wiring connections between control,
dehumidifier and HVAC system (where
applicable).
No power to
dehumidifier.
• Verify that the dehumidifier power switch
is ON.
• Verify the circuit breaker has not tripped.
No power to HVAC
equipment.
• Verify HVAC system switch is on.
• Verify the circuit breaker has not tripped.
Control does
not turn on
dehumidifier
output.
Incorrect wiring. Verify wiring connections between control and
dehumidifier.
Blank display
or missing
segments
during Test
mode.
LCD error. Replace control.
Display shows
Er.
Control detected an
internal error.
The control will need to be replaced.
Inaccurate
humidity
reading.
Control recently installed
after being stored in an
uncontrolled temperature
and humidity
environment.
Allow 48 hours for control to acclimate.
Offset has been applied
to the humidity reading.
Change the offset.
Control is mounted in
direct sunlight, above a
heat or humidity source,
or in the path of a supply
register.
Relocate the control.
TROUBLESHOOTING
Model D77 troubleshooting guide
14 D77 CONTROLLER INSTALLATION, OPERATION, AND MAINTENANCE MANUAL

TROUBLESHOOTING
Table 15-1: DEHUMIDIFIER Diagnostic Codes
Code Failure Mode Action Reset
E1 Internal
Humidity or
Temperature
Sensor Open or
Shorted
• If connection okay, replace User Interface. Cycle
Power
E3 Model D77
Remote Control
Communication
Loss
Check connections between Model D77 and
dehumidifier control board. Terminals should be
fully inserted and secured in the control board
and Model D77 control terminals.
• If connections are correct and secure, turn
off the dehumidifier and remove the Model
D77. Use a short section of 4-wire cable
to reconnect the Model D77 to the control
board. Turn the dehumidifier back on and
increase the dryness level setting on the
Model D77. If the dehumidifier turns on,
the problem is with the wiring between the
dehumidifier and control.
• If the dehumidifier does not turn on, call
Technical Support.
Self-
Correcting
E4 Insufficient
Capacity
Check the frost sensor connection at the power
board. Terminal should be fully seated on the
power board pins.
• Remove the side access panel and verify that
the sensor is secured to the suction line.
• If the sensor is connected and secured to the
refrigeration line proceed to the next step.
• Reset the fault by cycling power to the
dehumidifier.
• Turn the humidity setting down (below
room/home humidity level) to make a
dehumidification call.
• Allow the fan and compressor to run for
approximately 10-15 minutes and then
enter diagnostic test mode by simultaneously
pressing the UP ARROW and MODE buttons
for 3 seconds. The LCD will display the
temperature measured by the internal sensor
while also displaying AIR SAMPLING and
ON, the humidity measured by the internal
sensor while also displaying %RH and ON,
and the frost sensor temperature while also
displaying ON. Scroll through these values
and by using the UP/DOWN arrow buttons.
• Record values and call Technical Support.
Cycle
Power
RL-31 dehumidifier diagnostic codes
15
D77 CONTROLLER INSTALLATION, OPERATION, AND MAINTENANCE MANUAL

E5 High
Temperature
Thermistor
Failure
Check the high temperature sensor connection at
the power board. Terminal should be fully seated
on the power board pins.
• Remove the side access panel and verify
the sensor is not damaged and connected
to the refrigeration line coming from the
compressor.
• If the sensor is connected and secured to
the refrigeration line, it may need to be
replaced. Contact Technical Support to
confirm.
Cycle
Power
E6 Low
Temperature
Thermistor
Failure
Check the low temperature sensor connection at
the power board.
• Remove the side access panel and verify the
sensor is not damaged and connected to the
suction line.
• If the sensor is connected and secured to
the refrigeration line, it may need to be
replaced. Contact Technical Support to
confirm.
Self-
Correcting
E7 Float Switch
Open
Empty the condensate pan.
• Check the float switch connection at the
control board.
• If not using a float switch, verify jumper
is between float switch terminals on
dehumidifier control board.
• If the problem persists, replace the float
switch.
Self-
Correcting
E8 Inlet Air
Temperature
Out of 50°F
– 104°F (10 -
10°C) Range
or Dew Point
Below 36°F
(2°C)
Verify all ductwork is properly sealed.
• If no signs of leak points, contact Technical
Support.
Self-
Correcting
E9 Fan or
Compressor
Fault
Cycle power. If problem persists, contact
Technical Support.
Cycle
Power
TROUBLESHOOTING
RL-31 dehumidifier diagnostic codes
16 D77 CONTROLLER INSTALLATION, OPERATION, AND MAINTENANCE MANUAL

NOTES
17
D77 CONTROLLER INSTALLATION, OPERATION, AND MAINTENANCE MANUAL

NOTES
18 D77 CONTROLLER INSTALLATION, OPERATION, AND MAINTENANCE MANUAL

TWO-YEAR LIMITED WARRANTY
DRI-STEEM Corporation (“DriSteem”) warrants to the original user that its products will be free
from defects in materials and workmanship for a period of two (2) years after installation or
twenty-seven (27) months from the date DriSteem ships such product, whichever date is the earlier.
If any DriSteem product is found to be defective in material or workmanship during the applicable
warranty period, DriSteem’s entire liability, and the purchaser’s sole and exclusive remedy, shall
be the repair or replacement of the defective product, or the refund of the purchase price, at
DriSteem’s election. DriSteem shall not be liable for any costs or expenses, whether direct or
indirect, associated with the installation, removal or reinstallation of any defective product. The
Limited Warranty does not include cylinder replacement for electrode steam humidifiers or media
replacement for Wetted Media Systems.
DriSteem’s Limited Warranty shall not be effective or actionable unless there is compliance
with all installation and operating instructions furnished by DriSteem, or if the products have
been modified or altered without the written consent of DriSteem, or if such products have been
subject to accident, misuse, mishandling, tampering, negligence or improper maintenance.
Any warranty claim must be submitted to DriSteem in writing within the stated warranty period.
Defective parts may be required to be returned to DriSteem. Excluded from the Limited Warranty
are all consumable and wear and tear items such as cylinders, membranes, filters, or media
replacements. These items are subject to usual wear and tear during usage.
DriSteem’s Limited Warranty is made in lieu of, and DriSteem disclaims all other warranties,
whether express or implied, including but not limited to any IMPLIED WARRANTY OF
MERCHANTABILITY, ANY IMPLIED WARRANTY OF FITNESS FOR A PARTICULAR PURPOSE, any
implied warranty arising out of a course of dealing or of performance, custom or usage of trade.
DriSteem SHALL NOT, UNDER ANY CIRCUMSTANCES BE LIABLE FOR ANY DIRECT, INDIRECT,
INCIDENTAL, SPECIAL OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
TO, LOSS OF PROFITS, REVENUE OR BUSINESS) OR DAMAGE OR INJURY TO PERSONS OR
PROPERTY IN ANY WAY RELATED TO THE MANUFACTURE OR THE USE OF ITS PRODUCTS. The
exclusion applies regardless of whether such damages are sought based on breach of warranty,
breach of contract, negligence, strict liability in tort, or any other legal theory, even if DriSteem
has notice of the possibility of such damages.
By purchasing DriSteem’s products, the purchaser agrees to the terms and conditions of this
Limited Warranty.
EXTENDED WARRANTY
The original user may extend the term of the DriSteem Limited Warranty for a limited number of
months past the initial applicable warranty period and term provided in the first paragraph of this
Limited Warranty. All the terms and conditions of the Limited Warranty during the initial applicable
warranty period and term shall apply during any extended term. An extended warranty term of
an additional twelve (12) months or twenty four (24) months of coverage may be purchased. The
extended warranty term may be purchased until eighteen (18) months after the product is shipped,
after which time no extended warranties are available.
Any extension of the Limited Warranty under this program must be in writing, signed by DriSteem,
and paid for in full by the purchaser.
WARRANTY
19
D77 CONTROLLER INSTALLATION, OPERATION, AND MAINTENANCE MANUAL

Form No. D77-IOM-EN-REVA-0123
Part No. 890000-820 REV A
10016836
DRI-STEEM Corporation
a subsidiary of Research Products Corporation
DriSteem U.S. operations are ISO 9001:2015
certified
U.S. Headquarters:
14949 Technology Drive
Eden Prairie, MN 55344
800-328-4447 or 952-949-2415
952-229-3200 (fax)
Continuous product improvement is a policy of
DriSteem; therefore, product features and
specifications are subject to change without
notice.
DriSteem, Area-type, Drane-kooler, DriCalc,
Rapid-sorb, Ultra-sorb, GTS, and Vapor-
logic are registered trademarks of Research
Products Corporation and are filed for
trademark registration in Canada and the
European community.
Product and corporate names used in this
document may be trademarks or registered
trademarks. They are used for explanation
only without intent to infringe.
© 2023 Research Products Corporation
Patents pending.
Expect quality from the industry leader
Since 1965, DriSteem has led the industry
with innovative methods for humidifying and
cooling air with precise control. Our focus on
ease of ownership is evident in the design of
the GTS humidifier, which features cleanable,
stainless steel construction. DriSteem also
leads the industry with a Two-year Limited
Warranty and optional extended warranty.
For more information
www.dristeem.com
[email protected]
For the most recent product information
visit our website: www.dristeem.com