Aprilaire 1770A, 1750A SPOT installation, System Setup, Cycle Period, Dip Switch Configuration

Whole-Home installation (continued)

DIP SWITCH CONFIGURATION

•HVAC FAN ON: Activating the HVAC fan during dehumidification is recommended because it offers better circulation and balancing of indoor air conditions.. Running the HVAC fan during dehumidification does not affect moisture removal efficiency.. If the switch is put in the HVAC FAN OFF position, air is pulled through the unit, dehumidified, and circulated solely by the dehumidifier blower..

•CYCLE PERIOD: This determines how frequently the dehumidifier will sample the air to check the humidity level.. Set to 1 hour and adjust as needed..

•For Ventilation switch settings, see VENTILATION section beginning on page 12.

•For Local/External switch setting, see THIRD-PARTY CONTROL on page 17.

Figure 13 – Whole-Home DIP Switch Settings

SYSTEM SETUP

LOCAL	1	ON	EXTERNAL
HVAC FAN OFF	2		HVAC FAN ON
WHL HOUSE	3		CONVERTIBLE
VENT-AUTO	4		VENT-TIMED

CYCLE PERIOD

1	ON	30 MIN.
2		1 HOUR
3		2 HOUR
4		3 HOUR

90-1538

SEQUENCE OF OPERATION

•Sampling will occur once within the Cycle Period. Sampling is initiated with the first HVAC fan (Gs) call or at the end of the Cycle Period if a HVAC fan call is not received within the Cycle Period.. At the onset of sampling, the dehumidifier damper output turns on, the dehumidifier blower turns on, and the green Status LED flashes..

•After three minutes, the dew point of the incoming air is measured and compared to the set point on the control knob. If the dew point of the incoming air is above the set point, the compressor turns on and the green Status LED switches to solid illumination.. If the dew point is below the set point, the dehumidifier damper output turns off and the dehumidifier blower turns off along with the green Status LED..

•The dew point of the incoming air is continuously monitored during compressor operation. When the dew point of the incoming air falls below the set point on the control knob, the dehumidifier damper output turns off and the dehumidifier compressor and blower turn off along with the green Status LED..

SPOT installation

In this installation the dehumidifier is not ducted to the HVAC system and is used to dehumidify a specific area.. This installation is typically used in basements or crawl spaces.. The dehumidifier can remain non-ducted, however, to achieve specified performance it is recommended that the dehumidifier be ducted to the area requiring dehumidification.. When ducted, grilles should be installed on the inlet and outlet to increase the pressure drop across the unit.. 10 feet is the recommended distance between inlet and outlet grilles..

Required Components

Duct Work

Grilles with 8” duct collars

Optional Components

Condensate Pan & Normally Closed Float Switch

Model 70 Living Space Control

Third-Party Control

8