Aprilaire Dehumidifier 1700 User Manual

DUCTING

The Aprilaire Dehumidifier is supplied with two

8” round collars. These are packaged with a

condensate trap inside the unit behind the filter

access panel. When installing the collar make sure

the foam seal uniformly contacts the cabinet and

secure with 4 screws (not included). UL approved

8” diameter, insulated flexible duct is recommended

for all connections. Rigid metal duct may be used.

The duct should be capable of handling at least

2” w.c. of positive and 0.75” w.c. of negative

pressure. All joints and seams must be sealed.

• For optimal moisture removal, airflow should be at or above

275 CFM.

• The total static pressure across the dehumidifier must not

exceed 0.8” w.c. Check all pressures with the HVAC fan on.

• The outlet from the dehumidifier to the HVAC supply duct must be

located at least 6” downstream of the cooling coil.

• If connected to HVAC ductwork, the dehumidifier inlet must be located

at least 6” upstream of the HVAC system air cleaner. This will prevent

any trapped particulates from being drawn into the dehumidifier.

• If UV Germicidal lamps are installed in the HVAC system, use

appropriate methods to protect the flexible duct from the UV light.

Design air flow is 275 CFM @ 0.6” w.c. This is

equivalent to 70 ft. of 8” duct on the inlet and

outlet side of the dehumidifier. Elbows, turns and

the static pressure of the HVAC equipment will

affect the airflow through the dehumidifier.

• If air noise is a problem, install at least 5 feet of acoustical flexible

duct on the outlet and inlet of the dehumidifier.

DRAIN LINE

The included condensate trap

must be installed to the Model

1700. Use PVC primer and

cement to connect the trap to the

drain outlet on the Model 1700.

The drain outlet is located near

the On/Off toggle switch. Note

orientation of trap prior to

FIGURE 1

Drain Outlet

¹/2”

Drain Trap

2¹/2”

High Side

Low Side

90-961

cementing. The high side of the

trap mates with the Model 1700. The adjustable legs on

the Model 1700 must be disengaged approximately 1” to

accommodate the trap. Complete the assembly by piping

the trap to a drain. The trap must be primed with water

prior to start-up.

FIGURE 2

If the 1700 is installed in an attic or in an area where

flooding is a potential problem, it should be installed in a

secondary drain pan with a condensate overflow safety

switch. See page 12 for condensate overflow safety

switch wiring.

3“ MIN

CLEARANCE FOR

ACCESS PANEL

TOP VIEW

20” MINUMUM

CLEARANCE FOR FILTER

(EITHER SIDE)

HANGING

FILTER

If hanging the unit, use two unistruts to support the base

on the outside edges of the feet locations. There must

be at least 20” of clearance in front of one of the filter

access doors to allow removal of the filter.

6" MIN CLEARANCE FOR FILTER

90-970

3

WHOLE HOUSE INSTALLATION AND OPERATION

In this configuration the dehumidifier will pull air from the return duct. The air passes through the dehumidifier, where moisture is

removed, and then returned to the HVAC system downstream of the cooling coil in the supply plenum. This installation is used

when the HVAC unit conditions the area where dehumidification is needed. Connection to the HVAC unit for the primary living

space or basement HVAC unit is ideal for this installation.

REQUIRED COMPONENTS

OPTIONAL COMPONENTS

1 – 6508 Normally Closed Power Open Damper

Duct Work

6506 Ventilation Damper

24 VAC Transformer (10 VA minimum) for Ventilation Damper

8052 Outdoor Temperature Sensor

24 VAC Transformer (10 VA minimum)

Thermostat Wire

Normally Closed Condensate Overflow Safety Switch

FIGURE 3 – DUCTING

COOLING COIL

6“ MIN

AIR CLEANER

6“ MIN

SUPPLY

AIRFLOW

RETURN

AIRFLOW

OPTIONAL N.C.

VENT CONTROL

DAMPER

HVAC UNIT

(SEE PAGES 10-11)

OPTIONAL

OUTDOOR

AIR INTAKE

1700

3‘ MIN

N.C. BACKFLOW DAMPER

90-945

4

WHOLE HOUSE INSTALLATION AND OPERATION (CONTINUED)

DEHUMIDIFIER

CONTROL

N.C. BACKFLOW

FIGURE 4 – WIRING

24 VAC

(10 VA min)

DAMPER

TRANSFORMER

THERMOSTAT

HVAC EQUIPMENT

R

C

G

C

G

W

Y

W

Y

See page 10 for ventilation control wiring instructions.

See page 10 for fan cycling wiring instructions.

See page 12 for float switch wiring instructions.

90-962

FIGURE 5 – SETTINGS

SYSTEM SETUP

Standard

Fan Cycling

Ventilation

OFF

ON

OFF

See pages 10-11

OFF

MODEL 70

HVAC FAN

MODEL 70

HVAC FAN

See pages 10-11

WHL HOUSE

VENT-AUTO

CONVERTIBLE

VENT-TIMED

OFF

ON

OFF

CYCLE PERIOD

Standard

Fan Cycling

Ventilation

30 MIN.

1 HOUR

2 HOUR

3 HOUR

OFF

ON

OFF

See pages 10-11

30

MIN.

0

60

MIN.

MIN

Standard

Fan Cycling

Ventilation

OFF

See pages 10-11

OFF

TEST

CYCLE TIME

90-963

5

LOCALIZED INSTALLATION AND OPERATION

In this configuration the dehumidifier will pull air from an area in the home. The air passes through the dehumidifier, where

moisture is removed, and then is returned to the area. This installation is used when the HVAC unit conditions an area other than

where dehumidification is needed. An unconditioned basement or crawl space application is ideal for this installation.

REQUIRED COMPONENTS

OPTIONAL COMPONENTS

None

Duct Work

24 VAC Transformer (10 VA minimum) for Ventilation Damper

Thermostat Wire

6506 Ventilation Damper

8052 Outdoor Temperature Sensor

Grilles

Normally Closed Condensate Overflow Safety Switch

FIGURE 6 – DUCTING

OPTIONAL

OUTDOOR AIR INTAKE

OPTIONAL N.C.

VENT CONTROL

DAMPER

COOLING COIL

AIR CLEANER

(SEE PAGES 10-11)

SUPPLY

AIRFLOW

RETURN

AIRFLOW

HVAC UNIT

TO GRILLE OR

TO OPEN SPACE

FROM GRILLE

OR OPEN SPACE

1700

90-946

6

LOCALIZED INSTALLATION AND OPERATION (CONTINUED)

DEHUMIDIFIER

CONTROL

FIGURE 7 – WIRING

THERMOSTAT

HVAC EQUIPMENT

R

C

G

R

C

G

W

Y

W

Y

See page 10 for ventilation control wiring instructions.

See page 10 for fan cycling wiring instructions.

See page 12 for float switch wiring instructions.

90-964

FIGURE 8 – SETTINGS

SYSTEM SETUP

Standard

Fan Cycling

Ventilation

OFF

ON

OFF

MODEL 70

HVAC FAN

See pages 10-11

WHL HOUSE

VENT-AUTO

CONVERTIBLE

VENT-TIMED

ON

OFF

ON

OFF

CYCLE PERIOD

Standard

Fan Cycling

Ventilation

30 MIN.

1 HOUR

2 HOUR

3 HOUR

OFF

ON

OFF

See pages 10-11

30

MIN.

0

60

MIN.

MIN

Standard

Fan Cycling

Ventilation

OFF

See pages 10-11

OFF

TEST

CYCLE TIME

90-965

7

WHOLE HOUSE / LOCALIZED CONVERTIBLE INSTALLATION AND OPERATION

In this configuration the dehumidifier will automatically switch between whole-house dehumidification when the HVAC

equipment is on, and localized dehumidification when the equipment is off. This installation is used to dehumidify a whole house

and a separate unconditioned space like an unfinished basement, or an area where circulation from that location throughout the

entire house is undesirable.

REQUIRED COMPONENTS

OPTIONAL COMPONENTS

2 – 6508 Normally Closed Power Open Damper

2 – 6608 Normally Open Power Closed Damper

Duct Work

6506 Ventilation Damper

24 VAC Transformer (10 VA minimum) for Ventilation Damper

8052 Outdoor Temperature Sensor

24 VAC Transformer (40 VA minimum)

Thermostat Wire

Normally Closed Condensate Overflow Safety Switch

FIGURE 9 – DUCTING

OPTIONAL

OUTDOOR AIR INTAKE

COOLING COIL

AIR CLEANER

OPTIONAL

N.C. DAMPER

6“ MIN

3‘ MIN

SUPPLY

AIRFLOW

RETURN

AIRFLOW

HVAC UNIT

N.C. DAMPER

SUPPLY TO

UNCONDITIONED

SPACE

RETURN FROM

UNCONDITIONED

SPACE

1700

N.O. DAMPER

90-947

8

WHOLE HOUSE / LOCALIZED CONVERTIBLE INSTALLATION AND OPERATION (CONTINUED)

DEHUMIDIFIER

CONTROL

FIGURE 10 – WIRING

24 VAC

(40 VA min)

DEHUMIDIFIER SYSTEM DAMPERS

TRANSFORMER

THERMOSTAT

R

HVAC EQUIPMENT

R

C

G

WIRE NUT

G

W

Y

W

Y

See page 10 for ventilation control wiring instructions.

See page 10 for fan cycling wiring instructions.

See page 12 for float switch wiring instructions.

90-966

FIGURE 11 – SETTINGS

SYSTEM SETUP

Standard

Fan Cycling

Ventilation

OFF

ON

OFF

ON

OFF

ON

OFF

ON

MODEL 70

HVAC FAN

MODEL 70

HVAC FAN

WHL HOUSE

VENT-AUTO

CONVERTIBLE

VENT-TIMED

OFF

CYCLE PERIOD

Standard

Fan Cycling

Ventilation

30 MIN.

1 HOUR

2 HOUR

3 HOUR

OFF

ON

OFF

See pages 10-11

30

MIN.

0

60

MIN.

MIN

Standard

Fan Cycling

Ventilation

OFF

See pages 10-11

OFF

TEST

CYCLE TIME

90-965

9

VENTILATION / FAN CYCLING SETTINGS

The Aprilaire Dehumidifier has the option

to monitor HVAC heating, cooling and fan

calls to assure the HVAC fan has

OPTIONAL

VENTILATION

DAMPER

FIGURE 12

DEHUMIDIFIER

CONTROL

24 VAC

(10 VA min)

operated a predetermined amount of

time each 1/2, 1, 2 or 3 hours. The

dehumidifier can also open a normally

closed damper in an outdoor air intake to

ventilate during this predetermined

amount of time. This feature will

function even if the dehumidifier is

turned off at the dehumidifier or Model

70 Living Space Control. The only way to

disable this feature is by turning the

Cycle Time setting to OFF or turning

power off at the On/Off switch.

TRANSFORMER

THERMOSTAT

R

HVAC EQUIPMENT

R

C

G

WIRE NUT

G

W

Y

W

Y

OPTIONAL OUTDOOR

TEMPERATURE SENSOR

(Model 8052)

90-968

First, set the 1/2, 1, 2 or 3 hour period by setting the CYCLE PERIOD dip switches to determine

how often the dehumidifier should look to ventilate or cycle the HVAC fan.

(shown set

to 1 hour)

FIGURE 13

CYCLE PERIOD

Next, use the CYCLE TIME dial to determine how long during every cycle period the HVAC fan

30 MIN.

should operate. Adjust the dial from OFF to between 1 to 60 minutes. This will give you HVAC fan

operation from 1 to 60 minutes every 1/2, 1, 2 or 3 hours. A call for heat, cooling or fan from the

HVAC equipment will often satisfy the run time requirement. If not, the dehumidifier will turn on

the HVAC fan to assure that the cycle time is met. For example: If the home requires

ventilation of 20 minutes every two hours set the CYCLE PERIOD Dip Switch for 2 hours

to ON and rotate the CYCLE TIME to 20 minutes. If the HVAC equipment only has to run

for 10 minutes, the dehumidifier will turn on the HVAC fan for 10 minutes at the end of

the 2 hours to assure the ventilation / fan cycling time.

1 HOUR

2 HOUR

3 HOUR

90-783C

(shown set to

30 minutes)

FIGURE 14

30

MIN.

0

60

MIN.

MIN

Finally, if using the Ventilation Damper, determine if the ventilation should be restricted based

on outdoor temperature. Set the VENT-AUTO / VENT-TIMED dip switch to VENT-AUTO

(see Figure 15) to prevent opening the ventilation damper if the outdoor air is above 100°F,

below 0°F or except with a heat call between 20°F and 0°F. In the VENT-TIMED setting the

ventilation damper is activated regardless of outdoor conditions. Note: The Outdoor

Temperature Sensor (Model 8052) must be installed for this to work.

OFF

CYCLE TIME

TEST

90-783C

FIGURE 15

SYSTEM SETUP

OFF

ON

MODEL 70

You can also check the wiring of the dehumidifier to the HVAC equipment. If you rotate the

CYCLE TIME dial to TEST, the HVAC fan should come on and the Ventilation Damper

(if equipped) should open. DO NOT leave the CYCLE TIME in TEST.

HVAC FAN

WHL HOUSE

VENT-AUTO

CONVERTIBLE

VENT-TIMED

90-969

10

VENTILATION / FAN CYCLING SETTINGS (CONTINUED)

This installed option allows outside air to be combined with

the fan cycling feature from the dehumidifier, provided the

outside air temperature is in the acceptable range (0-100°F).

Note: The dehumidifier can control the HVAC fan to provide

fan cycling, regardless of whether or not an outdoor

ventilation duct is installed.

NORTH, EAST

OR WEST SIDE

OF HOME

FIGURE 16

OUTDOOR

TEMPERATURE

SENSOR

BRACKET

®

• An Aprilaire Normally-Closed Damper (Model 6506) should

OUTDOOR

TEMPERATURE SENSOR

LEADS

ABOVE EXPECTED

SNOW LINE

be installed in the outside air intake. It should be wired to the

terminals labeled “VENT DAMPER” on the dehumidifier

control board. Follow all installation instructions supplied

with the damper. Refer to each installation for ducting.

B2202617-D

FIGURE 17

• The Outdoor Temperature Sensor (Model 4278) should be

installed outside in a shaded location (Figure 16) or in an

outside air intake duct, but no more than 3 feet from the

outside (Figure 17).

CENTER LINE

36" MAX.

• The Outdoor Temperature Sensor is not affected by wire

length. However, do not route the wire alongside wires

carrying high voltage (115 VAC or greater), as interference

may occur.

OUTSIDE WALL

B2202617-E

• Connect the wires from the sensor to the terminals labeled “ODT SENSOR” on the dehumidifier.

See Figure 12 for terminal locations.

VENTILATION GUIDELINES

TABLE 1 – Air Cycling Time Setting (min./hr.)

Bedrooms

1. Based on ASHRAE 62.2 ventilation

requirement.

House Size

2. Based on outside air duct of 6”

dia., 20’ long flex duct, 0.15” w.c.

static pressure at outdoor air duct.

(square feet)

2

3

4

5

1000-1500

1501-2000

2001-2500

2501-3000

3001-3500

20

25

30

25

30

35

30

35

40

35

40

45

3. Based on ‘Cycle Period’ being in

the default (1 hour) position.

4. A longer outside air duct and/or

lower static pressure will require a

longer Ventilation Time.

As an example, for a 2,500 square foot home with 3 bedrooms, set the cycle time to 30 minutes of ventilation per one-hour cycle.

A longer outdoor air intake duct or lower return static pressure will increase the ventilation time required. Additionally, local

codes may affect the setting.

11

FLOAT SWITCH

If the Model 1700 is installed in an attic, the unit should be

placed in a drain pan with a normally closed condensate overflow

safety switch (also known as a float switch). The float switch

should be wired to the float switch terminals on the dehumidifier

control board. See Figure 18. Remove the jumper at the float

switch terminals. The compressor is disabled when the float

switch is open. The Model 1700 will continue to ventilate when

the float switch is open.

FIGURE 18

LOW VOLTAGE NORMALLY

CLOSED FLOAT SWITCH

90-968A

DIP SWITCH DEFINITIONS

MODEL 70 – OFF/ON (SYSTEM SETUP SWITCH #1):

WHL HOUSE / CONVERTIBLE (SYSTEM SETUP SWITCH #3):

Determines use of internal RH and temperature sensor or use

of the RH and temperature sensor on the Living Space Control

(Model 70).

Determines when the dampers are powered open or closed.

CONVERTIBLE position. The damper (DEH) terminals are

actuated when the HVAC equipment is making a call for heat,

cool or fan and the dehumidifier is making an internal blower

call for air sampling or dehumidification.

MODEL 70-OFF. Uses inlet RH and temperature sensor.

MODEL 70-ON. Uses Living Space Control (Model 70)

RH and Temperature Sensor.

WHL HOUSE position. The damper (DEH) terminals are

actuated any time the dehumidifier is making an internal

blower call for air sampling or dehumidification.

Default is MODEL 70-OFF.

HVAC FAN – OFF/ON (SYSTEM SETUP SWITCH #2):

The default position is WHL HOUSE.

Determines if the HVAC fan activates during a call for

dehumidification.

VENT-AUTO / VENT-TIMED (SYSTEM SETUP SWITCH #4):

Determines if ventilation is restricted based on outdoor

temperature

HVAC FAN-OFF position. The dehumidifier will not activate

the HVAC fan during a call for dehumidification; it will

however activate the HVAC fan for air cycling and ventilation.

VENT-AUTO position. The dehumidifier will measure the

outdoor temperature (through sensor, part # 8052) to

determine if the ventilation damper will open. If the outside

temperature is above 100°F or below 0°F the dehumidifier

will not actuate the ventilation damper terminals (VENT

DAMPER). If the outside temperature is between 0°F - 20°F,

the dehumidifier will only actuate the ventilation damper

terminals (VENT DAMPER) when the HVAC system is making

a call for heat. The dehumidifier will energize the HVAC fan

whether or not the ventilation damper opens.

HVAC FAN-ON position. The dehumidifier will activate the

HVAC fan during a call for dehumidification as well as for air

cycling and ventilation.

Default is HVAC FAN-OFF.

VENT-TIMED position. The dehumidifier will actuate the

ventilation damper terminals (VENT DAMPER) regardless of

the outdoor temperature.

The default position is VENT-AUTO.

12

SYSTEM CHECKOUT

1. Check the wiring to the HVAC equipment.

2. Rotate the main control knob clockwise to the “TEST” position.

3. If all is set up properly, the dehumidifier blower will turn on. The compressor will turn on after the dehumidifier blower has run

for 30 seconds. After 1 minute the dehumidifier blower and compressor will shut off (“TEST” mode only).

4. If the dehumidifier blower does not activate in TEST mode, refer to the Troubleshooting Guide.

®

5. For ventilation (optional) test, be sure that 24 VAC is applied in series with the Aprilaire Normally-Closed Damper

(Model 6506) and connected to the “VENT DAMPER” terminals on the dehumidifier control.

6. Rotate the “CYCLE TIME” potentiometer clockwise to the “TEST” position.

7. If all is set up properly, the HVAC blower will turn on and the ventilation damper will open. Both should be audible to the

installer. The HVAC blower will remain on and the ventilation damper will remain open for 1 minute or until the dial is turned

from the “TEST” position, whichever happens first.

8. If the optional ventilation damper or HVAC blower does not activate in TEST mode, refer to the Troubleshooting Guide.

13

TROUBLESHOOTING GUIDE

SYMPTOM

TROUBLESHOOTING PROCEDURE / POSSIBLE REASON

Dehumidifier is producing

hot air.

• Reheat of outgoing air will cause a temperature increase across the dehumidifier.

• Unit will possibly run continuously initially. After unit has “dried” home,

dehumidifier will cycle, reducing load.

Dehumidifier Blower is running,

but no airflow.

• Normally Open Damper was used instead of Normally Closed Damper in backflow.

• Total HVAC system static is higher than 0.8” w.c.

Dehumidifier not adequately

dehumidifying.

• Unit will need time to “dry” materials in home before effectively changing RH.

• Too little airflow through dehumidifier.

• Total HVAC system static is higher than 0.8” w.c.

• Compressor is not turning on.

• System undercharged.

Dehumidifier is not

draining properly.

• Check condensate trap to be sure it is clear.

• Check drain line for continuous slope.

HVAC fan does not turn

on when cycle time dial is

in “TEST” mode.

• Make sure there is power to the HVAC equipment.

• Check the wiring diagram for the R, C, W, Y, GH, and GS at the HVAC equipment,

thermostat, and the dehumidifier.

• Make sure the sensor is connected to the Outdoor Temperature Sensor terminals

or the System Setup block is set to “TIMED” mode.

• Check the voltage across the R and C terminals at the dehumidifier. Voltage

should be 18 VAC minimum - 30 VAC maximum.

• In “TEST” Mode, the HVAC fan will activate for 1 minute, DO NOT LEAVE IN TEST

MODE AS DEHUMIDIFIER WILL NOT OPERATE.

The dehumidifier damper does

not open in “TEST” Mode.

• Follow all of the system checkout procedures.

• Check the wiring diagram for the damper and 24 VAC transformers.

Fan cycling operates

continuously after the dial

is taken off “TEST” mode.

• If the HVAC equipment is making a Heat or Cool call, or the fan is in Continuous

Operation, fan cycling will remain on until the requirement set by the cycle

period dip switch and knob is met.

• If the interval is set at 1 HOUR and the cycle time is set at 60 minutes, fan

cycling will be on continuously. Change the setting to a lower amount if this is

not desired.

14

TROUBLESHOOTING GUIDE (CONTINUED)

SYMPTOM

TROUBLESHOOTING PROCEDURE / POSSIBLE REASON

The ventilation damper

does not open when the

HVAC fan is active.

• The damper will not open if the cycle time within the current period has already

been met. For instance if the cycle time is set to 5 minutes and the control has

already ventilated for 5 minutes in that interval, the damper will remain closed.

• If using the Outdoor Temperature Sensor, check

that it is installed in the Outdoor Air Intake a

maximum of 3 feet from the outside, or on the

North, East or West side of the house.

(Not in direct sunlight.)

TABLE 2

Outdoor

Temperature

-30˚F

-20˚F

-10˚F

0˚F

Resistance

229,500 OHMS

162,500 OHMS

116,500 OHMS

84,500 OHMS

62,000 OHMS

46,000 OHMS

34,500 OHMS

26,000 OHMS

20,000 OHMS

15,500 OHMS

12,000 OHMS

9,500 OHMS

7,500 OHMS

6,000 OHMS

• If the outdoor temperature is below 0°F or above

100°F, the damper will remain closed.

10˚F

20˚F

30˚F

40˚F

50˚F

60˚F

70˚F

80˚F

• Verify that the Outdoor Temperature Sensor

is reporting an accurate resistance. Remove the

Outdoor Temperature Sensor leads from ODT

Sensor terminals and check the resistance.

Compare the reading with the resistance shown

in Table 2.

90˚F

100˚F

The fan turns on unexpectedly.

The dehumidifier does not run.

• The control will turn on the fan as needed to meet the air cycling requirements

determined by the cycle time and cycle period settings.

• Follow all of the system checkout procedures.

• Check that the power switch on the dehumidifier is on.

• Check that the circuit breaker is not tripped. The dehumidifier requires a

minimum of 8 amps. The dehumidifier should be placed on its own dedicated

15 amp circuit.

The compressor never runs.

• If a float switch is not installed, confirm that the jumper is installed at the

float switch terminals on the control board.

• If a float switch is installed, confirm that the float switch is not open.

15

DEHUMIDIFIER SEQUENCE OF OPERATION

IF THE DEHUMIDIFIER IS NOT WIRED TO THE HVAC EQUIPMENT, THE DEHUMIDIFIER WILL SAMPLE AT THE END OF THE

CYCLE PERIOD.

With 3 minutes left in the Cycle Period, the dehumidifier will turn on the dehumidifier blower for 2 minutes. During this time the

temperature and relative humidity are measured and the dewpoint is calculated. If the dewpoint is higher than the setting at the

Control Knob then the dehumidifier compressor will turn on and the dehumidifier will run until it reaches set point.

After reaching the set point, the dehumidifier will not sample again until the end of the next Sample Period.

For example, if the Sample Period is set for 1 hour, the dehumidifier will sample at the end of the hour. Once the dehumidifier

reaches set point and shuts off, the dehumidifier will not sample again until the end of the next hour.

IF THE DEHUMIDIFIER IS WIRED INTO THE HVAC EQUIPMENT, THE DEHUMIDIFIER WILL SAMPLE THE FIRST TIME THE HVAC

EQUIPMENT RUNS IN THE CYCLE PERIOD OR AT THE END OF THE CYCLE PERIOD IF THE HVAC EQUIPMENT DOES NOT RUN.

For example, if the Cycle Period is set to 1 hour and the air conditioner starts 15 minutes into that hour, the dehumidifier will

sample when the air conditioner starts. Once the dehumidifier begins dehumidifying, it will run until set point is reached. If the

dehumidifier samples and determines that dehumidification is not needed, it will not sample again until the next Cycle Period.

DAMPER SEQUENCE OF OPERATION

In the Whole House Convertible to Localized installation 4 motorized dampers are used to control the air flow through the

dehumidifier. The dampers are energized when the HVAC equipment is running. This means that when the HVAC equipment

is running, the dampers are in the Whole-House position. When the HVAC equipment is not running, the dampers are in the

local position.

VENTILATION OR FAN CYCLING SEQUENCE OF OPERATION

If the dehumidifier is providing outdoor air ventilation or fan cycling, it is monitoring the HVAC equipment to provide the amount

of HVAC fan run time that has been set by the Cycle Time during the Cycle Period.

If an outdoor air damper has not been installed then the dehumidifier is providing fan cycling. The dehumidifier will monitor the

HVAC system and if the system has not run for the specified Cycle Time within the Cycle Period, the dehumidifier will energize

the HVAC fan through the G terminal to provide the desired amount of fan run time.

For example, if the Cycle Time is set for 10 minutes and the Cycle Period is set for 1 hour then the dehumidifier will provide

10 minutes of fan cycling or outdoor air ventilation. If the HVAC system runs for 5 minutes during this hour then the dehumidifier

will energize the fan for an additional 5 minutes.

If an outdoor air damper has been installed, then the Model 1700 is providing outdoor air ventilation. The 1700 will open the

outdoor air damper whenever the HVAC system is running, up to the amount of time specified by the Cycle Time. The

dehumidifier will energize the HVAC fan and open the outdoor air damper to provide the desired ventilation time if the HVAC

system has not run for the specified Cycle Time.

If an Outdoor Temperature Sensor has been installed, then the dehumidifier will use the outdoor temperature to determine if the

outdoor air damper is to be opened. If the outdoor temperature is above 100°F the damper will not open. If the temperature is

between 20°F and 0°F the damper will only open with a heat call. If the outdoor temperature is below 0°F, the damper will not

open. If the Outdoor Temperature Sensor is not installed then the temperature is not considered in opening the damper.

10006238 5.05

B2203431C

P.O. BOX 1467 • MADISON, WI 53701-1467 • PHONE: 800/334-6011 • FAX: 608/257-4357 • www.aprilairecontractor.com