Bryant 577D----A Heating Inputs, ECM Wet Coil Pressure Drop IN. W.C, 577D-- --A

Table 6 – Heating Inputs

HEATING INPUT (BTU/HR)*			NUMBER OF	GAS SUPPLY PRESSURE (IN. W.C.)		MANIFOLD PRESSURE (IN. W.C.)
					Natural		Natural
			ORIFICES
High Stage	Low Stage			Min	Max	High Stage		Low Stage
40,000	26,000	2		4.0	13.0	3.2∼ 3.8		1.4 ∼ 2.0
60,000	39,000	3		4.0	13.0	3.2∼ 3.8		1.4 ∼ 2.0
90,000	58,500	3		4.0	13.0	3.2∼ 3.8		1.4 ∼ 2.0
115,000	75,000	3		4.0	13.0	3.2∼ 3.8		1.4 ∼ 2.0
130,000	84,500	3		4.0	13.0	3.2∼ 3.8		1.4 ∼ 2.0

*Cubic ft of natural gas per hour for gas pressures of .5 psig (14 IN. W.C.) or less and a pressure drop of .5 IN. W.C. (based on a .60 specific gravity gas). Ref: Table 6.2 (b) NPFA 54 / ANSI Z223.1---2009.

Table 7 – ECM Wet Coil Pressure Drop (IN. W.C.)

UNIT							STANDARD CFM (SCFM)
SIZE
	600	700	800	900	1000	1100	1200	1300	1400	1500	1600	1700	1800	1900	2000	2100
24	0.005	0.007	0.010	0.012	0.015	–	–	–	–	–	–	–	–	–	–	–
30	–	0.007	0.010	0.012	0.015	0.018	0.021	0.024	–	–	–	–	–	–	–	–
36	–	–	–	0.019	0.023	0.027	0.032	0.037	0.042	0.047	–	–	–	–	–	–
42	–	–	–	–	0.014	0.017	0.020	0.024	0.027	0.031	0.035	0.039	0.043	–	–	–
48	–	–	–	–	–	–	0.027	0.032	0.036	0.041	0.046	0.052	0.057	0.063	0.068	–
60	–	–	–	–	–	–	–	–	–	0.029	0.032	0.036	0.040	0.045	0.049	0.053

Table 8 – Filter Pressure Drop Table (IN. W.C.)

FILTER SIZE										CFM
in. (mm)	500	600	700	800	900	1000	1100	1200	1300	1400	1500	1600	1700	1800	1900	2000	2100	2200	2300
20X20X1	0.05	0.07	0.08	0.1	0.12	0.13	0.14	0.15	—	—	—	—	—	—	—	—	—	—	—
(508x508x25)
24X30X1	—	—	—	—	0.05	0.6	0.07	0.07	0.08	0.09	0.1	—	—	—	—	—	—	—	—
(610x762x25)
24X36X1	—	—	—	—	—	—	—	0.06	0.07	0.07	0.08	0.09	0.09	0.10	0.11	0.12	0.13	0.14	0.14
(610x914x25)

577D-- -- A

IMPORTANT: When evaluating the refrigerant charge, an indicated adjustment to the specified factory charge must always be very minimal. If a substantial adjustment is indicated, an abnormal condition exists somewhere in the cooling system, such as insufficient airflow across either coil or both coils.

REFRIGERANT CHARGE

The amount of refrigerant charge is listed on the unit rating plate and/or the physical data table. Refer to the Refrigeration Service Techniques Manual, Refrigerants Section.

NO CHARGE

Check for leak. Use standard evacuating techniques. After evacuating system, weigh in the specified amount of refrigerant (refer to system rating plate).

LOW CHARGE COOLING

Use Cooling Charging Chart (Fig. 23). Vary refrigerant until the conditions of the chart are met. Note that charging charts are different from type normally used. Charts are based on charging the units to correct subcooling for the various operating conditions. Accurate pressure gauge and temperature sensing devices are required. Connect the pressure gauge to the service port on the suction line. Mount the temperature sensing device on the suction line and insulate it so that the outdoor ambient does not affect the reading. Indoor air CFM must be within the normal operating range of the unit.

TO USE COOLING CHARGING CHARTS

Take the liquid line temperature and read the manifold pressure gauges.

Refer to the chart to determine what the liquid line temperature should be.

NOTE: If the problem causing the inaccurate readings is a refrigerant leak, refer to Check for Refrigerant Leaks section.

NON-COMMUNICATING EMERGENCY COOLING / HEATING MODE: 4-WIRE THERMOSTAT

This mode of operation is provided only in the case where the UI has failed or is otherwise unavailable. If communications cannot be established with the UI, the Evolution furnace board will enable the standard thermostat input terminals to allow simple thermostatic control of the 577D--A unit.

For control with a standard thermostat, disconnect the ABCD connectors from both control boards and using No. 18 AWG color-coded, insulated type 90°C minimum or equivalent wire, make the connections between the standard thermostat, the furnace board, and the HP/AC board per Fig. 22. Recommend the use of interconnecting wire with 105C, 600V, 2/64” insulation.

The Evolution control will respond to cooling and heating demands with the maximum safe airflow based on gas furnace output and unit cooling capacity.

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