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LEGEND

C

— Contactor

HC

— Heater Contactor

IFC

— Indoor-Fan Contactor

OFC — Outdoor-Fan Contactor
RVS — Reversing Valve Solenoid
W

— Heating Stage

X

— Contact Energized

Y

— Cooling Stage

NOTES:
1. In heating mode, economizer damper blade will move to the mini-

mum position, and unit will operate as described for units without
economizer, regardless of outdoor air temperature.

2. The temperatures given in the graph are for demonstration purposes

only and may vary depending on which thermostat is used.

UNITS WITH ECONOMIZER

AVERAGE OUTDOOR-AIR TEMPERATURE GREATER THAN OAT SETTING

Thermostat Demand

G

Y1

Y2

W1

W2

C1

C2

IFC

OFC

RVS1

RVS2

HC

Second Stage Cooling

X

X

X

X

X

X

X

X

X

First Stage Cooling

X

X

X

X

X

X

X

Deadband (Offset)
First Stage Heating

X

X

X

X

Second Stage Heating

X

X

X

X

X

X

AVERAGE OUTDOOR-AIR TEMPERATURE LESS THAN OAT SETTING, BUT GREATER THAN −2 C (28 F)

Thermostat Demand

G

Y1

Y2

W1

W2

C1

C2

IFC

OFC

RVSI

RVS2

HC

Second Stage Cooling

X

X

X

X

X

X

X

X

First Stage Cooling

X

X

X

X

X

Deadband(Offset)
First Stage Heating

X

X

X

X

Second Stage Heating

X

X

X

X

X

X

UNITS WITHOUT ECONOMIZER

AVERAGE OUTDOOR-COIL TEMPERATURE LESS THAN −2C (28 F)

Thermostat Demand

G

Y1

Y2

W1

W2

C1

C2

IFC

OFC

RVSI

RVS2

HC

Second Stage Cooling

X

X

X

X

X

X

X

X

X

First Stage Cooling

X

X

X

X

X

X

X

Deadband (Offset)
First Stage Heating

X

X

X

X

Second Stage Heating

X

X

X

X

X

X

AVERAGE OUTDOOR-COIL TEMPERATURE GREATER THAN −2 C (28 F)

Thermostat Demand

G

Y1

Y2

W1

W2

C1

C2

IFC

OFC

RVSI

RVS2

HC

Second Stage Cooling

X

X

X

X

X

X

X

X

X

First Stage Cooling

X

X

X

X

X

X

X

Deadband (Offset)
First Stage Heating

X

X

X

X

Second Stage Heating

X

X

X

X

X

X

Fig. 31 — Typical Operating Sequence

—19—

Summary of Contents for 548C Series

Page 1: ... to that specified on unit rating plate 2 The electrical supply provided by the utility must be suf ficient to handle load imposed by this unit 3 Refer to Locate the Unit section on this page and Fig 2 for locations of electrical inlets condensate drain duct connections and required clearances before setting unit in place 4 This installation must conform with local building codes Refer to local pl...

Page 2: ...15 mm 36 in 1 side 305 mm 12 in the other The side getting the greater clearance is optional c Overhead 1525 mm 60 in to assure proper outdoor fan operation d Between units control box side 1065 mm 42 in e Between unit and ungrounded surfaces control box side 915 mm 36 in f Between unit and block or concrete walls and other grounded sur faces control box side 1065 mm 42 in g Horizontal supply and ...

Page 3: ...ould be 200 mm 8 in thick with 100 mm 4 in above grade Install a gravel apron in front of outdoor coil air inlet to prevent grass and foliage from obstructing airflow NOTE Horizontal units may be installed on a roof curb if required II UNIT DUCT CONNECTIONS On vertical units secure all ducts to roof curb and building structure Do not connect ductwork to unit On horizontal units duct flanges should...

Page 4: ...ated panels 3 Dimensions in are in millimeters 4 Roof curb galvanized steel 5 Attach ductwork to curb flanges of duct rest on curb 6 Service clearance 1220 mm 4 ft on each side 7 Direction of airflow SERVICE PLATE SIZES CONNECTOR PKG ACY Unit Size F Power G Control 548C090 120 19 25 NPT or 3 49 19 NPT 389004 203 29 51 NPT Fig 4 Roof Curb 4 ...

Page 5: ... 41 50 1054 50 12 1273 NOTES 1 Dimension in is in millimeters 2 Hook rigging shackles through holes in base rail as shown in detail A Holes in base rails are centered around the unit center of gravity Use wooden top skid when rigging to prevent rigging straps from damaging unit 3 Weights do not include economizer See Tables 1a and 1b for economizer weights CAUTION All panels must be in place when ...

Page 6: ...nal L s 1200 1600 Motor kW 1 12 1 50 Motor Frame 56 56 Fan r s Range 10 37 14 68 11 53 14 93 Maximum Fan r s 35 26 7 Motor Pulley Pitch Diameter 61 86 86 112 Open Closed mm Fan Pulley Pitch Diameter mm 140 178 Belt Type Length mm A 1219 A 1295 Pulley Center Line Distance mm 425 489 464 527 Speed Change Per Full Turn of 87 68 Movable Pulley Flange r s Movable Pulley Maximum Full 5 5 Turns from Clos...

Page 7: ...pe Drive Belt Belt Nominal Cfm 2600 3400 Motor Hp 1 5 2 0 Motor Frame 56 56 Fan Rpm Range 622 881 692 896 Maximum Fan Rpm 1600 1600 Motor Pulley Pitch Diameter 2 4 3 4 3 4 4 4 Open Closed in Fan Pulley Pitch Diameter in 5 5 7 0 Belt Type Length in A 48 A 51 Pulley Center Line Distance in 16 75 19 25 18 25 20 75 Speed Change Per Full Turn of 52 41 Movable Pulley Flange rpm Movable Pulley Maximum Fu...

Page 8: ...les is not required around ductwork on vertical discharge units On hori zontal discharge units a minimum clearance of 25 mm 1 in is required for the first 300 mm 12 in of ductwork 7 Flash weatherproof and vibration isolate all openings in building structure in accordance with local codes and good building practices C Electrical Connections WARNING The unit cabinet must have an uninter rupted unbro...

Page 9: ...onduit connectors in side panel power supply knockout openings indicated in Fig 3 Route power lines through connector to unit control box 3 For units with electric heat refer to Table 3 to deter mine appropriate power wiring figure Fig 12 14 and route power lines as indicated in appropriate figure A single point kit must be used with all heater packages See Fig 12 14 for single point kit electric ...

Page 10: ...he W2 wiring is required with optional 2 module heater package Fig 10 Low Voltage Connections With Economizer or Two Position Damper LEGEND AHA Adjustable Heat Anticipator CC Cooling Compensator P Plug TC Thermostat Cooling TH Thermostat Heating Field Wiring Factory Wiring Fig 11 Low Voltage Connections Without Economizer or Two Position Damper CONNECTION BOARD 10 ...

Page 11: ...ircuit breaker Requires 2 heater packages NOTES 1 MCA and MOCP values are calculated in accordance with NEC Na tional Electric Code U S A Standard Article 440 2 Motor RLA and FLA values are established in accordance with UL Underwriters Laboratories Standard 465 U S A Standard 3 Unbalanced 3 Phase Supply Voltage Never operate a motor where a phase imbalance in supply voltage is greater than 2 Use ...

Page 12: ...Single Point Kit 389008 203 and 389008 209 Fig 14 Electric Heater Power Wiring Connections 548C Single Point Kit 389008 205 and 389008 211 LEGEND FOR FIG 12 14 EQUIP Equipment FU Fuse GND Ground HTR Heater TB Terminal Block Field Wiring Factory Wiring 12 ...

Page 13: ...nt protec tor trips repeatedly there is a problem in the low voltage elec trical circuit i e electrical short ground or transformer overload Disconnect power correct the condition and check for normal unit operation D Accessory Installation At this time any required accessories should be installed on the unit Refer to Table 6 for available accessories Control wiring information is provided in the ...

Page 14: ...ock off plate over open ing on the access panel Block off plate MUST be installed before installing hood assembly see Fig 25 IMPORTANT Filters MUST be installed outside the unit on horizontal discharge applications with economizer or two position damper Otherwise the economizer or two position damper will have to be partially removed to access the fil ters The area of the field installed filters s...

Page 15: ... Outdoor Air 519 L s 1100 cfm Determine Setting 150 mm 6 in Fig 19 Minimum Position Setting FILTER ACCESS DOOR SCREEN RETAINER MANUAL OUTDOOR AIR DAMPER ADJUSTABLE SCREWS VENTILATION AIR SETTING Fig 20 Manual Outdoor Air Damper Fig 21 Air Hood Details 15 ...

Page 16: ...rd NOTE A 2 stage cooling thermostat must be installed in con junction with the economizer to have an integrated econo mizer with mechanical cooling operation A single stage ther mostat will have economizer operation only Fig 22 Block Off Plate Location NOTCH IN INDOOR COIL BLOCK OFF PLATE TWO POSITION DAMPER PLUG BAROMETRIC RELIEF DAMPER MOUNTING SCREWS POSITION SETTING BRACKET Fig 23 Economizer ...

Page 17: ...ver indoor fan motor access pan els and compressor access panel using screws saved in Step 19 MINIMUM POSITIO N OPEN 3 1 T P P1 T1 4 2 5 S S O D C TR B REV B 1 9 8 8 1 8 A H U M I D I T Y 90 70 60 30 10 D C B A 60 65 70 75 55 50 85 80 DAMPER DAMPER CLOSED OPEN OUTDOOR TEMP F REV 97 3672 CW SETPOINTS CCW CONTACTS SHOWN IN HIGH ENTHALPY RUSH AT 24VAC 3 mA MIN AT 11 VDC CONTACT RATINGS 1 5A RUN 3 5A ...

Page 18: ...he com pressor discharge line Be sure that caps on the ports are tight Unit is now ready for initial start up START UP I HEATING SECTION START UP AND ADJUSTMENTS CAUTION Complete the required procedures given in the Pre Start Up section on this page before starting unit Do not jumper any safety devices when operating the unit A Checking Heating Control Operation Start and check the unit for proper...

Page 19: ...e Heating X X X X Second Stage Heating X X X X X X AVERAGE OUTDOOR AIR TEMPERATURE LESS THAN OAT SETTING BUT GREATER THAN 2 C 28 F Thermostat Demand G Y1 Y2 W1 W2 C1 C2 IFC OFC RVSI RVS2 HC Second Stage Cooling X X X X X X X X First Stage Cooling X X X X X Deadband Offset First Stage Heating X X X X Second Stage Heating X X X X X X UNITS WITHOUT ECONOMIZER AVERAGE OUTDOOR COIL TEMPERATURE LESS THA...

Page 20: ...ntactor IFC and indoor fan motor IFM will be energized and the economizer damper blade will open to minimum position Note that if the indoor fan is on when the space thermostat calls for cooling terminal G is already energized and the economizer damper blade is at minimum position If the outdoor air temperature is below the outdoor air ther mostat OAT setting then the position of the damper blade ...

Page 21: ...Table 9 shows maxi mum amp draw of belt drive motor Refer to Tables 10 17 to determine fan speed settings Table 7 Fan R s at Motor Pulley Settings SI 548C MOTOR PULLEY TURNS OPEN 0 1 2 1 11 2 2 21 2 3 31 2 4 41 2 5 090 14 68 14 25 13 82 13 38 12 95 12 52 12 08 11 67 11 23 10 80 10 37 120 14 93 14 58 14 25 13 92 13 57 13 23 12 90 12 55 12 22 11 88 11 53 Table 8 Fan Rpm at Motor Pulley Settings Engl...

Page 22: ...0 400 450 500 R s BkW R s BkW R s BkW R s BkW R s BkW R s BkW R s BkW R s BkW R s BkW R s BkW 1100 8 7 0 42 10 1 0 59 11 1 0 75 12 2 0 93 13 1 1 12 14 0 1 30 14 8 1 51 15 7 1 77 16 4 2 02 17 2 2 35 1200 9 3 0 52 10 5 0 69 11 6 0 87 12 6 1 05 13 5 1 26 14 3 1 46 15 1 1 66 15 9 1 88 16 7 2 14 17 4 2 44 1300 9 8 0 64 11 0 0 81 12 1 1 01 13 0 1 20 13 9 1 41 14 7 1 63 15 5 1 84 16 2 1 98 16 9 2 29 17 6...

Page 23: ...2 0 4 0 6 0 8 1 0 1 2 1 4 1 6 1 8 2 0 Rpm Bhp Rpm Bhp Rpm Bhp Rpm Bhp Rpm Bhp Rpm Bhp Rpm Bhp Rpm Bhp Rpm Bhp Rpm Bhp 2200 503 0 50 585 0 71 653 0 92 716 1 15 772 1 38 824 1 63 884 1 95 934 2 30 916 2 64 1019 3 09 2400 534 0 61 613 0 84 677 1 06 738 1 30 794 1 55 844 1 81 892 2 08 944 2 40 987 2 76 1039 3 20 2600 565 0 74 639 0 97 703 1 20 761 1 46 816 1 74 866 2 01 913 2 29 957 2 58 1004 2 91 105...

Page 24: ...E AND MAINTENANCE To ensure continuing high performance and to minimize the possibility of premature equipment failure periodic mainte nance must be performed on this equipment This combina tion heating cooling unit should be inspected at least once each year by a qualified service person NOTE TO EQUIPMENT OWNER Consult your local dealer about the availability of a maintenance contract WARNING The...

Page 25: ...led remove economizer by disconnecting Molex plug and economizer mounting screws Refer to Accessory Economizer Installation In structions for further details 3 Slide filters out of unit 4 Clean coil using a commercial coil cleaner or dish washer detergent in a pressurized spray canister Wash both sides of coil and flush with clean water For best results backflush toward return air section to re mo...

Page 26: ...mally used Charts are based on charging the units to the correct superheat for the various operating conditions Accu rate pressure gage and temperature sensing device are re quired Connect the pressure gage to the service port on the suction line Mount the temperature sensing device on the suction line and insulate it so that outdoor ambient tempera ture does not affect the reading Indoor air cfm ...

Page 27: ...Fig 38 Cooling Charging Charts 548C090 Fig 39 Cooling Charging Charts 548C120 27 ...

Page 28: ...TROUBLESHOOTING HEATING TROUBLESHOOTING CHART 28 ...

Page 29: ...COOLING TROUBLESHOOTING CHART 29 ...

Page 30: ...ue wire on SW1 If motor works replace control board If motor does not work replace motor Switches set incorrectly Jumper R to G Indoor fan should start and damper should move until SW3 is deactivated If damper moves past SW3 and SW3 is wired correctly replace control board Economizer operation limited to minimum position Outdoor air thermostat OAT or enthalpy control EC set too high Set at correct...

Page 31: ......

Page 32: ...Copyright 1992 Carrier Corporation CATALOG NO 000 376 ...

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