Bryant 580G DIP Switch Conguration, DIP Switch Factory Settings, Cooling Sequence of Operation

Table 4 Ð DIP Switch Con®guration

SETTING	1	2	3	4	5	6	7	8
						Time Guard
			Expansion	Field	Modulated	Override ON
OPEN						IN CONJUNCTION	Gas Heat	Heat Pump
	Ð	Ð	Board	Test	Power
						WITH FIELD TEST Ð		Operation
			Operation	ON	Exhaust
						Set Minimum
						Damper Position
CLOSED		Thermostat	Base Control	Field	CV	Time Guard		Air Conditioner
	CV			Test	Power		Electric Heat
		Used	Board Only			Override OFF		Operation
				OFF	Exhaust

LEGEND

CV Ð Constant Volume

NOTES:

1.The OPEN side of the DIP switch is marked ``OPEN.'' When the rocker switch is on the ``OPEN'' side of the switch, the switch is open.

2.When the unit is being ®eld-tested (DIP switch 4 to OPEN), the func- tion of DIP switch 6 changes and it is used to set the minimum damper position.

Table 5 Ð DIP Switch Factory Settings

UNIT	1	2	3	4	5	6	7	8
580G,H	Closed	Closed	Closed	Closed	Closed	Closed	Open	Closed

·DIP switch 6 con®gures the Time Guard override and, when used with the ®eld test function, sets the mini- mum damper position

·DIP switch 7 con®gures the unit for gas heat or elec- tric heat

·DIP switch 8 con®gures the unit for heat pump or air conditioner operation

10.Adjust economizer. Check that outdoor-air damper is closed and return-air damper is open.

IMPORTANT: Unit power must be on for 24 hours prior to start-up. Otherwise, damage to compressor may result.

11.The optional non-modulating power exhaust is a two- stage design where the operation of the exhaust fans is linked to economizer position. When the supply fan is running and the economizer is 25% open, the base module closes contacts, activating 2 exhaust fans. When the economizer position reaches 75% open, the base mod- ule activates the other 2 exhaust fans. The fans will turn off when the economizer closes below the same points.

START-UP

I. COOLING SECTION START-UP AND ADJUSTMENTS

CAUTION: Complete the required procedures given in the Pre-Start-Up section on page 20 before starting the unit.

Do not jumper any safety devices when operating the unit.

Do not operate the compressor when the outdoor tem- perature is below 40 F (unless accessory low ambient kit is installed).

Do not rapid-cycle the compressor. Allow 5 minutes between ``on'' cycles to prevent compressor damage.

A. Checking Cooling Control Operation

Start and check the unit for proper cooling control operation as follows:

Place SYSTEM switch in COOL position and FAN switch in AUTO. position. Set cooling control below room temperature.

Observe that compressor, condenser fan motor, and evapora- tor blower motors start. Observe that cooling cycle shuts down when control setting is satis®ed.

B. Cooling Sequence of Operation

On power up, the control module will activate the initializa- tion software. The initialization software reads DIP switch no. 1 to determine it is in the closed position. Next, DIP switch no. 2 is read to determine it is closed for thermostat opera- tion. The initialization sequence clears all alarms and alerts; re-maps the input/output database for operation; sets maxi- mum heat stages to 2; and sets maximum cool stages to 3. Power up takes a random 1 to 63 seconds plus 5 minutes.

The TSTAT function performs a thermostat based control by monitoring Y1, Y2, W1, W2 and G inputs. These functions control stages: cool1, cool2, heat1, heat2 and the indoor fan, respectively.

The control module will operate economizer and run diagnos- tics to monitor alarms at all times.

If the thermostat energizes the G input, the control module will turn on the indoor fan and open the economizer dampers to minimum position. If thermostats are used to deenergize the G input, the control module will turn off the indoor fan and close the economizer dampers.

When cooling, G must be energized before cooling can oper- ate. The control module determines if outdoor conditions are suitable for economizer cooling. For the economizer to func- tion for outside air cooling: the enthalpy must be below the enthalpy set point; the outdoor-air temperature must be equal to or less than 65 F; the SAT (supply-air temperature) ther- mistor must not be in alarm; and the outdoor air reading is available. When these conditions are satis®ed, the control mod- ule will use economizer as the ®rst stage of cooling.

When Y1 input is energized, the economizer will be modu- lated to maintain SAT at the set point temperature. The default is 55 F. When SAT is above the set point, the econo- mizer will be 100% open. When SAT is below the set point, the economizer will modulate between minimum and 100% open position. When Y2 is energized, the control module will turn on compressor 1 and continue to modulate the econo- mizer as described above. If the Y2 remains energized and the SAT reading remains above the set point for 15 minutes,

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