Thermo Products PHCFA072DV4R operation manual On and OFF Blower Delay Time Switch Settings

Motor Blower Speed

Three interconnected blower speed outputs are provided. A “G” call for fan will provide power to the LOW speed tap only. A “W” heat call will provide power to the Heat speed tap only. A “Y” cooling call will provide power to the Cool speed tap only.

In the case of thermostat calls for “Y” and “W” together, blower speed selection will be determined by the input that was first initiated. In the case where the control is in a cooling mode with both “Y” and “W” inputs energized and then the “Y” input is removed, the cooling blower off time will be executed prior to the control switching into a heating mode. In the case where the control is in a heating mode with both “Y” and “W” inputs energized and then the “W” input is removed, the heating blower off time will be executed prior to the control switching into a cooling mode. In the case where a call for fan “G” already exists and either a “W” or a “Y” call is initiated, the blower speed will switch to the respective “W” or a “Y” speed following the blower on delay for that call.

The speed taps are interconnected and interlocked, only one speed may be powered at any one time. When a speed is to be operated, the speed select relays are operated to select the path to the motor tap and then the enable relay is operated to switch the operating power to the selected motor speed tap. If the speed of the running motor is to be changed, first the enable relay removes power from the motor, the new speed is selected and then power is restored to the motor.

Blower On and Off Delays

Four Heat blower on and four blower off delays are selected by two dip switches for each function. Refer to Table 7 for specific delay values.

DIP SWITCH 2 SECTION STATE				BLOWER DELAY TIMES
1	2	3	4		ON - SEC	OFF - MIN
OFF	OFF				30
ON	OFF				60
OFF	ON				120
ON	ON				240
		OFF	OFF			2
		ON	OFF			4
		OFF	ON			6
		ON	ON			8

Table 7: ON and OFF Blower Delay Time Switch Settings

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