Bryant 581B installation instructions Ð PARABLADE Economizer Troubleshooting, Ð36Ð

Table 22 Ð PARABLADE Economizer Troubleshooting

PROBLEM	CAUSE		REMEDY
Damper does not open.	Evaporator fan not on.	Check wiring between G on connection board and indoor fan contactor.
	No power to economizer motor.	1. Disconnect power at TR and TR1. Disconnect jumper across P and P1.
		2.	Connect jumper across TR and 1.
		3.	Connect jumper across T1 and T.
		4.	If connected, remove enthalpy sensor from terminals S0 and +. Factory-
			installed 620 ohm resistor should be connected to terminals SR and +.
		5.	Apply power (24 vac) to terminals TR and TR1. The LED should be off
			and the damper should be in the closed position.
		6.	Disconnect the factory-installed 620 ohm resistor from terminals SR and
			+. The LED should light up and the motor should drive towards open. If
			this does not happen, replace the economizer control module.
	Economizer motor failure.	If the indoor fan and economizer motor are energized, verify that there is a
		minimum of 24 vac at terminals TR and TR1. If the motor is not operating,
		replace the motor.
Economizer operation	Economizer control module	1.	To simulate high or low enthalpy, reconnect the factory-installed 620 ohm
limited to minimum	failure.		resistor across terminals SR and +.
position.		2.	Connect 1.2 Kohm checkout resistor across terminals SO and +. Turn the
			enthalpy set point to ``A.'' The LED should turn on, indicating low en-
			thalpy. The motor should drive towards open. If LED does not light, re-
			place module. If motor does not drive open, check motor operation.
		3.	Turn the enthalpy set point to ``D.'' The LED should turn off, indicating
			high enthalpy. The motor should drive towards closed. If these actions do
			not occur, replace module.
		4.	Disconnection 1.2 Kohm checkout resistor before resuming operation.
Damper does not close.	No power to economizer.	1. Disconnect power at TR and TR1. Disconnect jumper across P and P1.
		2.	Connect jumper across TR and 1.
		3.	Connect jumper across T1 and T.
		4.	If connected, remove enthalpy sensor from terminals SO and +. Factory-
			installed 620 ohm resistor should be connected to terminals SR and +.
		5.	Apply power (24 Vac) to terminals TR and TR1. The LED should be off
			and the damper should be in the closed position.
		6.	Disconnect the factory-installed 620 ohm resistor from terminals SR and
			+. The LED should light up and the motor should drive towards open. If
			this does not happen, replace the economizer control module.
	Return spring failure.	If power to unit is off and damper does not close, check for a bound linkage.
		If linkage is not bound, then internal spring may be broken. Replace
		actuator.
	Economizer motor failure.	If the economizer control module is functioning properly, verify that there is a
		minimum of 24 Vac at terminals TR and TR1. If the motor is not operating,
		replace the motor.
Damper does not open	Sensor incorrectly wired or bad.	To verify sensor operation, reconnect the + lead of the outdoor enthalpy sen-
or close according to		sor to the + terminal of the economizer control module. Connect a DC mil-
enthalpy readings.		liammeter between terminals SO of the economizer control module and
		terminals S of the enthalpy sensor. The milliammeter should indicate be-
		tween 3 and 25 mA if the sensor is operating properly. If the milliammeter
		indicates 0, the sensor may be wired backwards. If any other readings are
		shown, replace the sensor.

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