Carrier 48EL User Manual

Number One AirConditbninq Maker

Division of Carrier Corporation

Carrier Parkway • Syracus

N Y 13221

Combination Heating/Cooling Units

INTRODUCTION

The 48EL and EM combination heating/cooling units are complete systems designed for outdoor installation on slab or rooftop.

Installation consists of: rigging and mounting the unit, attaching ductwork, making single gas, electrical and condensate connections, and attaching thermostat leads. A field-furnished filter rack is required in the return airstream.

RECEIVING THE UNIT

Examine the unit carefully for any damage incurred in shipment. If damaged, file claim with

transportation company immediately.

Check unit nameplate to ensure that unit

electrical requirements match available power supply, and that unit is designed for use with the proper gas type (natural or liquefied petroleum).

INSTALLATION

Check national and local gas and electrical codes and local building codes for any special installation requirements.

Unit Location — Install unit outdoors. Maintain

clearance of at least 2 ft from building. Unit may face in any direction since neither the condenser air inlet nor the flue outlet (Fig. 1) are affected by wind. Do not locate unit near sources of con taminated air.

Although the unit is weatherproof, position unit so that water and ice from roofs or eaves cannot fall directly on the unit. •

SPACE LIMITATIONS — Provide sufficient space for unimpeded airflow and for wiring and servicing

unit (Fig. 1).

OUTSIDE AIR LIMITATIONS - Although there are no restrictions on either the percentage or the temperature of the outside air circulated thru the

unit, the rate of moisture condensation from the

combustion process increases significantly when return air temperature drops below 50 F. Protect

the drain holes in the bottom pan against ice buildup if outside air of below freezing tempera ture is used.

VIBRATION ISOLATION - The unit compressor, evaporator fan and condenser fan are mounted on isolators to minimize vibration. Additional

isolation is not required for slab mounting. With some types of roof construction, however, the use of field-furnished rubber pad type isolators may be advisable.

Unit Rigging

1. Sling the unit perpendicularly to shipping skid runners. Use spreader bars to prevent damage from sling or cable.

2. Raise unit to desired location and remove shipping skid.

3. Mount and level the unit as indicated in Unit Support and Mounting section.

Unit Support and Mounting

LEVELING THE UNIT - Level the unit from end to end but pitch the unit slightly (3/8 to 1/2 in.) towards the condensate drain on the service access

face of the unit (Fig. 1). Use the unit frame as a leveling reference.

SLAB MOUNTING ^ Mount the unit on a concrete pad, cement blocks, bricks or creosoted wood of sufficient area and strength to support the unit weight (Table 1) without distortion or damage

and maintain the drainage pitch recommended

above.

A gravel apron prevents grass and foliage from

obstructing the condenser air inlet (Fig. 1).

FLAT OR RECESSED ROOF MOUNTING should be as close as possible to the roof duct opening.

Place the unit on at least 2 wooden 2 x 4 in. or 2 x

6 in. sleepers.

Sleepers may be perpendicular to or parallel to the unit mounting rails, but must span at least 2 roof joists or purlins to distribute unit weight. Set the sleepers in roof cement or mastic. Do not plug drain holes in the compressor or furnace compartment.

Do not support the unit by the ends of the base rails, nor use vibration isolators at these points. Unit will not be properly supported and could sag in the middle.

PITCHED ROOF MOUNTING - Construct a sturdy welded or bolted frame of 1-1/2 x 1-1/2 x

1/4 in. or larger angle iron, with frame members at right angles to unit rails. Make provisions for securing unit to frame. Use roof cement or mastic where frame is in contact with roof.

Form 48EL-1SI

Table 1 — Physical Data

UNIT MODEL OPERATil^ WEIGHT (lb) REFRIG (22) CHGIIb-oz) COMPRESSOR

Cylinders Rpm (60-Hz)

CONDENSER FAN

Air Quantity (Cfm)

Motor Hp

evaporator fan

Size (in.) Nominal Cfm Rpm Range Max Allowable Rpm Fan Pulley Pitch Diameter (in.) Motor Pulley Pitch Diameter (in.) Belt Speed Change per Full Turn of

Moveable Pulley Flange (Rpm)

Factory Setting — Full Turns Open

Motor Hp

CAPACITY (1000 Btuh)

Cooling

Heating Input/Bonnet*

MAX EXTERNAL STATIC PRESSURE

Heating (in. W.C.)

FILTERSt (1-in. thick)

Disposable — No. ...Size (in.)

Permanent^ — No. ...Size (in.)

HEAT TEMPERATURE RISE (F) GAS CONNECTION (in.)

48EL006

48EM006

" soi

"^5”5

GB30K

___

010

3500

Propeller Type, Direct Drive; Vertical Discharge

2700

1/3

Centrifugal, Belt Drive: Horizontal Discharge

10x9 1900

820-1250

1500

1 9-2 9

4L40

3/4

110/82 5

150/112 5

2 16x20

45-75

1/2

’537'

5 5

1 20x25 1 25x25

^Ratings shown for elevations up to 2000 ft above sea level For elevations above 2000 ft deduct 4% capacity for each

1000 ft above sea level fRecommended field-supplied filter JBased on 0 055 in wg pressure drop or less thru filter

WIND CAP 4‘-0"OVERHEAD SPACE COMBUSTION AIR REQUIRED FOR SERVICE

INLET BOX yTv AND AIRFLOW

2-0 \

ALL SIDES

li- DIAM HOLE FOR

i DIAM HOLE FOR

CONTROL WIRING

LINE POWER WIRING

EVAPORATOR AND HEATING SECTION ACCESS PANEL

i- FPT GAS

VALVE CONN

CONDENSATE

’ DRAIN CONN

r-oi DM

SUPPLY GAS I:.; . CONN HOLE^'

|DIAM(6MTG HOLES)

О INDOOR AIR

Ф CONDENSER AIR

Certified dimension drawings available on request

Space required for service Design certified by A G A for installation on combustible-type floor with minimum space of 2'-0" on all sides

Fig. 1 — Physical Data and Dimensions

Ductwork Installation — For air duct system design

information, refer to Carrier System Design

Manual, Part 2. System airflow must be within the range of temperature rise and external static pressure shown on the unit A.G.A. rating plate.

Bolt or screw ductwork to unit supply and return air duct flanges and seal joints with sheet metal flashing. Flange location and dimensions are given in Fig. 1. Use flexible connectors between ductwork and unit to dampen vibration. If a single split duct is connected to the unit, use a gasket to prevent air bypass between supply and return sides.

Insulate and weatherproof all external duct work. Secure ducts to building structure and weatherproof all duct openings in wall or roof. Ducts passing thru unconditioned spaces must be insulated and provided with a vapor barrier.

Filter Installation (Field-Supplied)

1. Locate filter in return air system. Convenient location for filter is inside building behind

return air grille. Size and number of required filters is given in Table 1.

2. Attach filter manufacturer’s instructions to

filter rack.

ASSEMBLE WIND CAP AND

COMBUSTION-AIR INLET BOX

WIND CAP ASSSMSi-Y

auEPiPc

(PARTOF WiNOCAP

ASS£M8LY)

EY£L£TS(3)

« yHSATrSHfEXP

‘^^COLtAR

COMBUSTfON

AiR inlet BOX

RETAININS CUP

TOP COVER OF UNIT

TCP COVER EXTRUSION

FLUE BOX

EXTRUSION

HEATING SECTION

ACCESS PANEL

Fig. 2 — Wind Cap and Air Inlet Box Assembly

Locate — The wind cap assembly, heat-shield collar

and combustion-air inlet box (items 1, 2 and 3 of Fig. 2) are shipped within the condenser section except 460 volt units.

On 460 volt units, only the combustion-air inlet box is shipped within the condenser section. The heat-shield collar and wind cap assembly are shipped in a separate package.

Remove 6 sheet metal screws and lift condenser fan, grille and orifice from the top of the con denser section (Fig. 3). Remove and discard metal banding securing the wind cap and/or inlet box and remove the item(s) from the condenser section.

Before replacing the condenser fan, grille and orifice, remove any shipping tape from the con denser fan.

Assemble (Fig. 2)

1. Mount the combustion-air inlet box (item 3) by sliding the horizontal box flange under the retaining clip on the unit top cover. Fasten the inlet box with sheet metal screws provided.

2. Place end of heat-shield collar and secure wind cap assembly (item 1 ) with 3 sheet metal screws thru wire cage eyelets.

PIPING AND WIRING

Gas Piping — Install piping per national and local

codes and ANSIZ223.1 entitled “National Fuel

Gas Code,” (published by American Gas Asso-

Fig. 3 — Removing Condenser Fan

and Orifice Assembly

ciation, 1515 Wilson Blvd., Arlington (Rosslyn), VA 22209).

1. Furnish the gas line from the main gas supply to the unit gas valve (Fig. 4). Connection at gas valve is 1 /2 in. FPT.

2. Size the supply pipe for 0.3-in. wg maximum pressure drop and for the volume of gas required (Tables 2, 4 and 5). Pipe size must equal or exceed size of gas connection at unit.

3. Use pipe dope approved for use with liquefied petroleum (LP) gases.

Pitch all horizontal pipe runs towards the unit

1 /4-in. per 15 ft to prevent trapping condensed

moisture.

Support piping to maintain proper pitch, prevent strain on unit controls, and prevent accidental movement of piping.

Install a tee for attachment of a dirt and moisture drip pocket (Fig. 4). Tee should be at same level or below gas valve connection. Drip

pocket must be protected against freeze-up

Install manual shutoff valve on gas piping per local codes.

8. Provide a ground joint union in the gas supply line near the unit gas valve.

9. Protect gas piping from freezing temperatures Gas stoppage can result from failure to insulate pipe against wide or sudden temperature changes.

10. When piping is completed, check entire gas assembly and field piping with soap and water solution.

Never use an open flame for leak testing.

NOTE Connection to unit gas valve is 1/2 in FPT

Fig. 4 — Gas Piping Details

Table 2 — Maximum Pipe Cap. (cfh)*

PIPE

LENGTH (ft)

10 20

30 73 40 50 60 70 80 90

100

*Cfh — Cu ft/hr based on 0 3 in wg pressure drop and 0.6

gas specific gravity

NOTE: Correction is not necessary for normal number of fittings nor for 0.7 gas specific gravity unless specified

NOMINAL PIPE SIZE (in.)

1/2

132 278 520

92 190 350 63

56 115

— — — —

—

3/4

152 130

105 195

96 180 90 84 79

1 1-1/4

285 590 245 500 215 440

170 350

160 320 150 305

1050

730

400 370

Drain Piping — The condensate drain connection (3/4-in. MPT) is on service access face of unit

(Fig. 1). Since drain is on the suction side of the indoor (evaporator) fan, it must be trapped to prevent leakage back into the unit. Trap should be at least 3 in. deep and should be formed of flexible material or in such a manner as to resist freeze-up damage. Wiring — The design center voltage for each unit is stamped on the unit nameplate. The supply voltage

at the unit must be within maximum and minimum limits shown on nameplate and in Tabled. Phase unbalance on 3-phase units must be within 2%.

Contact local power company if correction is necessary. Operation of the unit on improper line

voltage or with excessive phase unbalance is con sidered abuse and is not covered by Carrier warranty.

Provide a branch circuit fused disconnect of adequate size to handle unit starting current (Table 3). Disconnect must be within sight of and readily accessible from the unit in accordance with Section 440-14 of the National Electrical Code (NEC). Provision for locking switch at open (off) position is advisable to prevent power from being turned on while unit is being serviced.

Use only UL approved copper or copper-clad aluminum power wires.

UNIT CONNECTION

1. Attach field power conduit to 1-1/8 in. hole at front of high voltage (line wiring) junction box (Fig. 1).

2. Run conduit so that access panels can be readily removed.

3. Splice field power wires to the pigtail leads in the junction box. Wire nuts are provided for either copper or aluminum wire. These must be field insulated.

4. Route the control-voltage field wiring thru the 7/8-in. hole in low-voltage junction box (Fig. 1). If conduit is not used, protect wires by inserting diaphragm grommet into the hole.

Make all connections to pigtail leads, but do not use aluminum control wire for splice connection to the copper pigtails.

Accessory Installation and Wiring

REMOTE CONTROL CENTER - The installation

instructions for this combination heating-cooling

thermostat and subbase are included with the accessory.

Locate the thermostat on an inside wall or column where it is affected only by the average temperature of the room. The subbase has slots for direct mounting on wall or on vertical outlet box.

Run the thermostat cable or equivalent single

leads of no. 18 colored wire from subbase ter

minals to 7/8-in. diameter hole in access side of unit (Fig. 1) and attach to low voltage (control wiring) terminals in junction box (Fig. 5).

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