Bryant 558D installation instructions Durablade Economizer Troubleshooting, Damper does not

Table 20 Ð Durablade Economizer Troubleshooting

	PROBLEM	CAUSE		REMEDY
Damper does not		Indoor (evaporator) fan is off.	1.	Check to ensure that 24 vac is present at terminal C1 on the IFC or that
open.				24 vac is present at the IFO terminal. Check whether 24 vac is present at
				PL6-1 (red wire) and/or PL6-3 (black wire). If 24 vac is not present, check
				wiring (see unit label diagram).
			2.	Check proper thermostat connection to G on the connection board.
		No power to economizer	1. Check that SW3 is properly making contact with the damper blade. Check
		motor.		that SW1 is in the NC (normally closed) position.
			2.	Check diode D18. If diode is not functioning properly, replace D18.
			3.	Con®rm that the economizer control board is grounded properly at PL6-4
				(brown wire) and at brown terminal of the economizer control board
				(brown wire). The economizer motor must also be grounded properly at the
				negative motor terminal (brown wire).
			4.	Verify SW1 and SW3 are working and wired properly (see unit label
				diagram).
			5.	Check for 24 vac input at both PL6-1 (red wire) and PL6-3 (black wire). If
				24 vac not present, check unit wiring (see unit label diagram). If 24 vac is
				found in both places, check for 24 vac at the yellow terminal of the econo-
				mizer control board (yellow wire). If 24 vac power is not present, replace the
				economizer control board.
		Economizer motor failure.	If the indoor (evaporator) fan and economizer motor are energized, verify that
			there is a minimum of 18 vdc at the positive motor terminal. If the motor is not
			operating, replace the motor.
Economizer op-		OAT or EC set too high.	1.	Set at correct temperature (3 F below indoor space temperature).
eration limited to			2.	Check OAT or EC by setting above outdoor temperature or humidity level. If
minimum position.				the OAT or EC switches do not close, replace OAT or EC.
		Verify economizer control	1.	Perform the following tests when OAT or EC is closed, Y1 is called for and
		board is correctly wired and		damper is at minimum position. Con®rm 24 vac on gray terminal of the
		works properly.		economizer control board (gray wire). If 24 vac is not present, check wiring
				(see unit label diagram).
			2.	Verify that SW1 and SW3 are wired correctly and working properly (see unit
				label diagram).
			3.	Check to ensure that 24 vac exists at PL6-2 (blue wire). If 24 vac is not
				present, check wiring (see unit wiring label diagram).
			4.	Check 24 vac output at PL6-10 (white wire). If 24 vac is not present, replace
				economizer control board.
		Check SAT.	1.	After verifying that the OAT and EC settings and the economizer control
				board wiring are correct, check to ensure that the 24 vac terminal of the SAT
				has 24 vac (white wire). If OAT, EC, and control board are functioning and
				wired properly and no 24 vac exists, check wiring (see unit label diagram).
			2.	If supply-air temperature is greater than 57 F, 24 vac should be found at
				terminal T2 on the SAT (pink wire). If 24 vac is not present, replace SAT.
Damper does not		Incorrect wiring of	1.	Verify that SW2 and SW4 are wired and working properly (see unit label
close.		economizer.		diagram).
			2.	Check diode D19. If diode is not functioning properly, replace D19.
		Verify economizer control	1.	After verifying that the wiring is correct, modulate the damper to the mini-
		board is functioning properly.		mum position. Remove the calls for G.
			2.	If the damper does not move, check for 24 vac at PL6-1 (red wire). If 24 vac
				is not present, check wiring (see unit label diagram).
			3.	If damper still does not move, check for 24 vac at blue terminal of econo-
				mizer control board (blue wire). If 24 vac is not present, replace the econo-
				mizer circuit board.
		Check SAT.	1.	After verifying that the wiring is correct and the economizer control board is
				functioning properly, place the OAT or EC switch in the closed position.
				Place a call for Y1 and open the damper to the fully open position. Con®rm
				that the 24 vac terminal of the SAT has 24 vac (white wire). If 24 vac is not
				present, check wiring (see unit label diagram).
			2.	If supply-air temperature is less than 52 F, 24 vac should be found at
				terminal T1 on the SAT (violet wire). If 24 vac not found, replace SAT.
		Economizer motor failure.	If economizer control board and SAT are functioning properly, verify that there is
			a minimum of 18 vdc at the positive motor terminal. If a minimum of 18 vdc is
			present and the motor is still not operating, replace the motor.
Economizer		Verify that close-on-power-	1.	Check voltage potential across batteries. If lower than 14 vdc, replace close-
damper does not		loss and economizer control		on-power-loss power supply (9-v alkaline batteries). It is recommended that
close on power		board are functioning		you check this emergency power supply on a regular basis or whenever the
loss.		properly.		®lters are changed.
			2.	If the close-on-power-loss and economizer control board are functioning
				properly, check for 14 vdc or higher at the blue terminal of the economizer
				control board (blue wire) when power is disconnected from unit. If 14 vdc is
				not present, replace the control board.
	LEGEND
C1	Ð Common Power
EC	Ð Enthalpy Control
IFC	Ð Indoor (Evaporator) Fan Contactor
IFO	Ð Indoor (Evaporator) Fan On
OAT Ð Outdoor-Air Thermostat
PL	Ð Plug
SAT	Ð Supply-Air Thermostat
SW	Ð Economizer Position Switch

Ð33Ð