Heat Controller HEV/H manual Ecm Blower Control, Hev/H Series, Heat Controller, Inc

Heat Controller, Inc. HEV/H SERIES Installation, Operation & Maintenance

ECM BLOWER CONTROL

The ECM fan is controlled directly by the DXM2 control board that converts thermostat inputs and CFM settings to signals used by the ECM motor controller. To take full advantage

of the ECM motor features, a communicating multi-stage thermostat should be used (ATC32U**).

The DXM2 control maintains a selectable operating airflow [CFM] for each heat pump operating mode. For each operating mode there are maximum and minimum airflow limits. See the ECM Blower Performance tables for the maximum, minimum, and default operating airflows.

Airflow levels are selected using the configuration menus of a communicating thermostat (ATC32U**) or diagnostic tool (ACDU**). The configuration menus allow the installer to independently select and adjust the operating airflow for each of the operating modes. Air flow can be selected in 25 CFM increments within the minimum and maximum limits shown in the ECM Blower Performance Table. The blower operating modes include:

•First Stage Cooling (Y1 & O)

•Second Stage Cooling (Y1, Y2, & O)

•First Stage Cooling in Dehumidification Mode (Y1, O, & Dehumid)

•Second Stage Cooling in Dehumidification Mode (Y1, Y2, O, & Dehumid)

•First Stage Heating (Y1)

•Second Stage Heating (Y1 & Y2)

•Third Stage (Auxiliary) Heating (Y1, Y2, & W)

•Emergency Heating (W with no Y1 or Y2)

•Fan (G with no Y1, Y2, or W)

It is highly recommended that ATC32U** or ACDU** be used to set dehumidification mode electronically. For dehumidification settings on other units using the non-communicating stat, refer to DXM2 AOM (part #97B0003N15).

The ECM motor includes “soft start” and “ramp down” features. The soft start feature is a gentle increase of motor rpm at blower start up. This creates a much quieter blower start cycle.

The ramp down feature allows the blower to slowly decrease rpm to a full stop at the end of each blower cycle. This creates a much quieter end to each blower cycle and adds overall unit efficiency.

The ramp down feature is eliminated during an ESD (Emergency Shut Down) situation. When the DXM2 ESD input is activated, the blower and all other control outputs are immediately de-activated.

The ramp down feature (also known as the heating or cooling “Off Delay”) is field selectable by the installer. The allowable range is 0 to 255 seconds.

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