Heat Cfm Adjustment (Violet Wire); Outdoor Unit Size (Blue Wire); Continuous Fan (Yellow Wire); Low-Voltage Circuit - Dettson DCAH Série Guide D'installation

2.7.1

HEAT CFM ADJUSTMENT (VIOLET WIRE)

The heating mode airflow can be adjusted for desired air
temperature rise or desired water temperature delta T. Note
that a condensing boiler requires low return water
temperature and a non-condensing boiler requires a higher
return water temperature.
Move the Violet wire to the proper A, B, C, D pin selection.
Refer to Table 2 for airflow data.
2.7.2

OUTDOOR UNIT SIZE (BLUE WIRE)

Select the outdoor unit system size (TON) by using the Blue
wire (refer to Table 2).
The installer needs to properly select the outdoor unit size to
ensure proper airflow delivery of the DCAHV. This selection
affects all operational modes (airflow) with the exception of
heat modes.
Move the Blue wire to the proper A, B, C, D pin selection.
The outdoor unit size corresponding directly to each pin
letter is listed in Table 2.
2.7.3 SYSTEM TYPE (ORANGE WIRE)
The DCAHV operates only with «AC» selection. Do not move
the orange wire in order to get the proper airflow for cooling.
Identified «SYSTEM TYPE» on the control card.
In «AC» mode, the Air Conditioner provides approximately
400 CFM per ton for greater efficiency and humidity control
with the AC/HP CFM ADJUST set to the nominal (NOM) tap.
To achieve more or less than 400 CFM per ton, move tap to
(HI) or (LO) position respectively. Refer to Table 2 for exact
CFM setting.
The factory setting is AC
2.7.4 AC/HP CFM ADJUST (BLACK WIRE)
Select Medium, Low, or High Airflow
To provide airflow at rates described above, the AC/HP
ADJUST select is factory set to the nominal (NOM) tap. The
adjust selections HI/LO will regulate airflow supplied for all
operational modes.
HI provides 15% airflow over nominal in heating and
ventilation modes and 10% over nominal in all other modes.
Lo provides 15% airflow below nominal in heating and
ventilation modes and 10% below nominal in all other
modes.
Adjust selection options are provided to adjust airflow
supplied to meet individual installation needs for such thins
as noise, comfort, and humidity removal. (Refer to Figures 6
and 11 and Table 2)
2.7.5 ON/OFF DELAY (WHITE WIRE)
Select desired time delay profile
NOTE: Delay selections are active in heating mode only.
Cooling mode have a 90 seconds OFF delay at 100% airflow
and zero (0) ON delay programmed into the ECM motor that
cannot be overridden.
Four (4) motor operation delay profiles are provided to
customize and enhance system operation. (Refer to Figures
6 and 11 and Table 2)
Selection options are:
First tap: 30 seconds ON delay at 13% airflow and No OFF
delay (factory setting).
Second tap: 45 seconds ON delay at 13% airflow and No
OFF delay (factory setting).
Third tap: 60 seconds ON delay at 13% airflow and No OFF
delay (factory setting).
Fourth tap: 90 seconds ON delay at 13% airflow and No
OFF delay (factory setting).
2.7.6

CONTINUOUS FAN (YELLOW WIRE)

NOTE: If installed with a two-stage outdoor unit, do not
select HI speed continuous fan. If HI is selected, low stage
compression will also run HI fan speed possibly resulting in
insufficient dehumidification.
Select desired fan speed when thermostat is set on
continuous fan by using the yellow jumper wire. (Refer to
Figures 6 and 11 and Table 2)
1. LO speed – factory setting, 50% cooling mode airflow.
2. MED speed – move connector to MED, 80% cooling
mode airflow.
3. HI speed – move connector to HI, 100% cooling mode
airflow.
2.7.7

LOW-VOLTAGE CIRCUIT

Fusing and Reference
The low-voltage circuit is fused by a board-mounted 5-amp
automotive fuse placed in series with the transformer SEC2
and the R circuit.
referenced to chassis ground through a printed circuit run at
SEC1 connected to metal standoff marked with ground
symbol.
2.8

INSTALLATION OF ACCESSORIES

Electrical shock hazard.
Turn OFF electrical power at the fuse box or service panel
before making any electrical connections and ensure a
proper ground connection is made before connecting line
voltage.
Failure to do so can result in death or bodily injury.
2.8.1

HUMIDIFIER AND HUMIDISTAT CONNECTION

Fan Control Board terminals HUM1 and HUM2 are provided
for direct connections to the low-voltage control of a
humidifier through a standard humidistat (refer to Figure 7).

Figure 7 : Standard humidistat connections

7
The C circuit of the transformer is
WARNING