Thermo Products 125n, chx-3 75n, 100n operation manual StageBlower Settings from factory C

All installations and services must be performed by qualified service personnel.

Modifications to ECM blower speed settings are done using the S3 and S4 dip switch controls. Thermo Pride two-stage furnaces are factory shipped at the CFM settings listed below in Table 4C.

2-Stage Blower Settings (from factory)

Table 4C

Unit	Control Board	Heating	Heating	Constant Fan	Cooling
	Dip Switch	CFM	CFM
				CFM	CFM
	Settings	(low fire)	(high fire)
	SW3 1-4 Off
CDX3-75	SW4 1-3 Off	885	1012	500	1000
	SW4 4 On
CHX3-75	SW3 1-4 Off	760	931	500	1000
	SW4 1-4 Off
	SW3 1-4 Off
CDX3-100	SW4 1-3 Off	1094	1340	600	1200
	SW4 4 On
CHX3-100	SW3 1-4 Off	1015	1243	600	1200
	SW4 1-4 Off
	SW3 1-4 Off
CDX3-125	SW4 1-3 Off	1366	1673	700	1400
	SW4 4 On
CHX3-125	SW3 1-4 Off	1270	1556	700	1400
	SW4 1-4 Off

For adjustments to the Cooling CFM settings, as well as all additional CFM changes, please reference the dip switch tables listed in the ECM operation manual. (Included with every furnace.)

5.DE-HUMIDIFICATION

The ECM motor in conjunction with the W/R 50V51-843 has a feature to enhance de-humidification in the cooling mode. In the dehumidify mode the indoor blower motor (ECM) reduces CFM. By reducing airflow the indoor coil runs colder and thus extracts more moisture from the air.

The W/R 50V51-843 is shipped from the factory with dipswitch S5-2 set to on for system that do not have a dehumidification connection from the thermostat. For systems using a thermostat that provides dehumidification option move dip switch S5-2 to “OFF”. With the S5-2 switch in the “OFF” position the air conditioning fan speed will be reduced 30% from the normal CFM setting when the humidity in the home is higher than the set point of the dehumidistat.

6.FIELD WIRING AND REPLACING WIRING

Field wiring between the furnace and devices not attached to the furnace shall conform with the temperature limitation for Type T wire[63°F rise (35°C)] when installed in accordance with the manufacturer’s instructions. If any of the original factory supplied furnace wiring is replaced or a separate device other than the thermostat is wired internal to the unit 105°C thermoplastic or equivalent wire must be used.

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