Ecm Interface Board - Bosch QV Series Installation, Operation And Maintenance Manual

18 | Electrical—Low-Voltage Wiring QV Series Heat Pumps

ECM Interface Board

Thermostat wiring is connected to the 10-pin
screw-type terminal block on the lower-center
portion of the ECM Interface Board. In addition to
providing a connecting point for thermostat wiring,
the interface board also translates thermostat
inputs into control commands for the Electronic
Commutated Motor (ECM) DC fan motor and
displays an LED indication of operating status. The
thermostat connections and their functions are as
shown in Fig. 11.
Fig. 11 ECM Interface Board
[1] Motor Harness Plug
[2] Blower CFM Adjustment
[3] Motor Settings
[4] Dehumidification Indication
[5] Thermostat Contact Inputs
[6] CFM Count Indicator
[7] Thermostat Input Status Indication
[8] Reheat Digital Outputs
[9] Thermostat Outputs
[10] 24 VAC
[11] Hot Gas Re-Heat Enable Switch
Subject to change without prior notice
8733829041 (2021/07) QV Series Heat Pumps