User Guide
Table Of Contents
- Product Data
- Features/Benefits
- Model Number Nomenclature
- AHRI Capacities
- Unit Dimensions
- Unit Dimensions
- 36-60
- Accessory Dimensions
- 1. Roof curb must be set up for unit being installed.
- 2. Seal strip must be applied, as required, to unit being installed.
- 3. Roof curb is made of 16-gauge steel.
- 4. Attach ductwork to curb (flanges of duct rest on curb).
- 5. Insulated panels: 1-in. (25.4 mm) thick fiberglass 1 lb. density.
- Performance Data
- Application Data
- Electrical Data
- Connection Wiring Schematic 208/230-1-60
- Controls
- Operating Sequence
- 2. The normally open contacts of energized contactor (C) close and complete the circuit through compressor motor (COMP) to condenser (outdoor) fan motor (OFM). Both motors start instantly.
- 3. The set of normally open contacts on the interface fan board (IFB) are closed which energizes a circuit to the indoor fan motor (IFM).
- Guide Specifications
- Packaged Gas Heating/Electric Cooling Units Constant Volume Application
- HVAC Guide Specifications
- General
- Products
- Guide Specifications (Continued)
- 2. Compressor Start Kit (single phase units only):
- 3. Thermostat:
- 4. Crankcase Heater:
- 5. Economizer:
- 6. Filter Rack Kit:
- 7. Flat Roof Curb:
- 8. Flue Discharge Deflector
- 9. Low Ambient Package:
- 10. Manual Outdoor Air Damper:
- 11. Square-To-Round Duct Transitions (24-48 models):
- 12. Time Guard II
- 13. Low Pressure Switch Kit
577C--K Ultra Low NOx: Product Data
Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations.
10
Selection Procedure (With Example)
DETERMINE COOLING AND HEATING REQUIREMENTS AT
DESIGN CONDITIONS:
Given:
Required Cooling Capacity (TC) .......................................46,000 Btuh
Sensible Heat Capacity (SHC)...........................................34,000 Btuh
Required Heating Capacity ................................................72,000 Btuh
Condenser Entering Air Temperature ............................... 95°F (35°C)
Indoor-Air Temperature ..................80°F (27°C) edb 67°F (19°C) ewb
Evaporator Air Quantity....................................................... 1600 CFM
External Static Pressure ................................................ 0.440 IN. W.C.
Electrical Characteristics ........................................................208-1-60
SELECT UNIT BASED ON REQUIRED COOLING CAPACITY
Enter Net Cooling Capacities table at condenser entering temperature of
95°F (35°C). Unit 48 at 1600 CFM and 67°F (19°C) ewb (entering wet
bulb) will provide a total capacity of 47,000 Btuh and a SHC of 35,000
Btuh. Calculate SHC correction, if required, using Note 4 under Cooling
Capacities tables.
SELECT ELECTRIC HEAT
In the Gas Heating Capacities and Efficiencies table, note that the 48090
unit will provide 73,000 Btuh with an input of 89,000 Btuh.
DETERMINE FAN SPEED AND POWER REQUIREMENTS AT
DESIGN CONDITIONS.
Before entering the air delivery tables, calculate the total static pressure
required. From the given example, the Wet Coil Pressure Drop Table,
and the Filter Pressure Drop Table:
External Static Pressure 0.30 IN. W.C
Filter 0.06 IN. W.C
Wet Coil Pressure Drop 0.07 IN. W.C
Total Static Pressure 0.43 IN. W.C
At 0.43 IN. W.C. ESP (external static pressure) and MED speed the
motor delivers between 1664 CFM and 1627 cfm. Interpolation
estimates 1653 CFM at .43 IN. W.C. Thus, MED delivers CFM needed.
SELECT UNIT THAT CORRESPONDS TO POWER SOURCE
AVAILABLE.
The Electrical Data Table shows that the unit is designed to operate at
208-1-60.