Carrier 50ME User Manual

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Hot Water/Glycol Heating 160,000 to'800,000 Btuh

Eiectric Cooling 180,000 to 360,000 Btuh Electric Heating 180,000 to 540,000 Btuh

Gas Heating 480,000 to 720,000 Btuh

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0 ® Commercial buildings

:© Carrier Corporation 1982

Form 48MA/50ME-3P

No hot decks. . .no cold decks. . . no zoning dampers. . .no energy waste!

It’s what you don’t get with Carrier’s Zone-Mizer Modular Multizone unit that sets it apart from all the others.

You don’t get hot decks or cold decks because the Carrier design gives each zone module its own cooling coil and heating section. Each zone module operates independently. One unit can heat, cool, dehumidify, reheat, and ventilate up to 12 different zones simul taneously. All this means real energy savings. . .there’s no wasteful duplica tion of effort as in hot deck/cold deck

units. For still more energy savings, Zone-Mizer provides up to 3 steps of electric heat or gas heat with an inter

mittent pilot ignition in every zone.

Something else you don’t get. . . zoning dampers. Since the Carrier de sign doesn’t have hot and cold decks, it doesn’t need zoning dampers. By elimi nating them from the picture, you eliminate the adjustments, service, and

operating problems that go along with zoning dampers.

Five sizes, offering capacities to 37 tons, provide equipment flexibility and economy. One large unit may serve where 2 units were required before; or units of different sizes may be mix/ matched to deliver the heating/cooling capacity required in a specific applica tion. And the choice of gas, elecfric or hot water/glycol coils allows you to select a unit that can deliver maximurn operating economy and convenience by

taking advantage of an already available heating plant or favorable area fuel rates.

1 Etched solid copper circuit

panels have interchangeable plug-in relays to minimize parts stocking Cir cuit breakers that may be used as dis connect switches, terminal boards to simplify installation of accessories, a control circuit shutoff switch and 24volt controls are all standard.

Motorized outdoor air inlet

damper — A simple rheostat adjust

ment on the unit (or on the optional re mote control panel) sets the damper to control the amount of outdoor air admitted.

5 Dependable cooling — Each ser

viceable hermetic compressor system has cylinder unloaders for capacity con trol and electric power savings. Crank case heaters, accumulators, filter driers and low-ambient starting controls are also standard.

Time Guard® electrical circuit pre

vents rapid cycling of the compressor if

occupant tampers with the thermostat. Compressor cannot short-cycle on a safety device, such as the low-pressure switch, should someone forget to clean the air filters.

Capacity control permits a wide oper ating range. During light loads the com pressor automatically unloads to re duce operating costs and maintain steady compressor operation. When the load drops below the minimum

unloader stage, the hot gas bypass con trol provides continuous cooling operation.

Built-in safety controls prevent damage to unit components. Included are high- and low-pressure switches, overtemperature limit switches and overload protection for all motors.

When specifying a multizone unit, choose the one that makes a point of doing something about installation problems. . .the Carrier Zone-Mizer

Modular Multizone. It’s a sturdy, onepiece unit — factory-wired, piped, and charged. It arrives ready to be set in place on the specially designed roof curb. Make the power and control con nections and that’s it. Initial adjust ments are trouble free — you won’t even need a factory engineer at start up. The total package carries the UL label or is design certified by AGA.

3 Fused 115-volt convenience out

let in the control box provides power at the unit for work lights and small power tools.

4 Motormaster® solid-state con

denser fan speed control permits

year-round operation of refrigeration system down to -20 F ambient.

6 Polyurethane foam sandwich

access panels are of Weather Armor

galvanneal steel. Their thermal resis tance prevents sweating at outdoor conditions up to 77 F dew point And they are strong enough to support a 250-pound man.

/ Rugged extruded aluminum

frames and protective grilles provide

strength and good looks. Unit will not sag during rigging.

Low silhouette — The cabinet has no vents or hoods to break up the clean appearance. The curb-mounted unit

seldom requires a parapet to hide it

from street level view.

<5 Humidry® coil — This separate

cooling coil dehumidifies the outdoor air before it is mixed with the return air to prevent high indoor relative humidities in humid weather and during partial load operation.

‘ 5 Large filter area — Over 41 square

feet of standard filter area is factory

supplied. Filter tracks will accept one-in. or 2-in., high- or low-velocity, permanent or throwaway, standard or high-efficiency filters.

10 Electric heater section (SOME)

— Each zone module has its own 2- or 3-stage electric heater assembly or hot water/glycol heating coil. Electric heaters have 24-volt relays and 115-volt contactors. Each heating element has circuit breakers and automatic thermal reset. Each leg has its own heat limiter (fusible link).

Each hot water/glycol heating coil has its own solenoid operated shutoff valve and balancing valve. All heating coils are prepiped to supply and return manifolds which also include a bleed valve.

Gas heating (48MA) — Each zone module has stainless steel burners, Porcelon™ heat exchangers and its own redundant gas valve. Natural gas units also have a regulator for each gas valve. Intermittent pilot ignition and forced draft combustion are standard on all units.

Zonc-Mizer^” Modular Multizone concept. How it works. . .

Outdoor air enterirvg the unit thru the side louvers is filtered and then cooled and dehumidified by the Humidry® cooling coil when mechanical cooling is operating. Return air entering the unit from below is mixed with this condi tioned air The mixture is then filtered. After passing thru the indoor air fans, the air is discharged into the individual

zone modules. The air passing thru

each zone module is either cooled or

heated in response to a signal from the thermostat controlling that module. This treated air then continues to the individual zone duct systems, thus pro viding a constant air pattern and volume on each cooling coil and heating assembly

Each zone module cooling coil has its own solenoid valve to admit refrigerant when needed. When 2 or more mod

ules are grouped for a larger zone re

quirement, 2-stage cooling can be provided. . .and controlled by one simple 24-volt mercury bulb thermostat

This condenser end view of unit (034 and 040) shows the 3 outdoor air fans and the side condenser air inlet grilles. The 2 end panels may be easily removed for control box and compressor accessibility.

SPLITS AIRSTREAM INTO ZONES

ADDS ADDS DIRECTS HEATED

SEPARATE OR SEPARATE OR COOLED AIR

COOLING HEATING TO INTERIOR ZONES

and why it’s best.

Low operating costs

On partial load, the Carrier compres sors unload cylinders to match com pressor output to cooling needed with up to 6 steps of reduction. To maintain balanced operation, the hot gas bypass system diverts hot refrigerant to the outdoor air cooling coil as needed.

There is no mixing of warm and cold airstreams in the modular design. Just that amount of energy required to heat or cool a given zone is used — and no more.

Heating is available 3 ways. . .

Electric heating, provided by 2- or 3-stage electric heaters in each module, gives up to 36 steps of capacity, again

using the minimum amount of energy.

Hot water/glycol heat may be speci fied to utilize an already available heating plant.

Gas heating models utilize inter

mittent pilot ignition in each module designed to consume a minimum amount of energy.

Low»temperature operating capa bility. . .You can use the economizer

cycle with outdoor air for “free cooling,” as with competing units. However, with

Carrier’s head pressure controlled re

frigeration system, you can often save

money by using refrigeration to cool the space instead. So-called “free

cooling” is expensive if a large quantity

of cool outdoor air must be heated for the zones which do not require cooling. The Carrier refrigeration system can operate at outdoor temperatures down to -20 F. The Carrier modular design, therefore, is not dependent on an economizer cycle for cooling at low outdoor temperatures.

Superior humidity control

One of the major concerns in multizone applications has been the control of humidity, especially in schools where moisture comes from large groups of people as well as from outdoor venti lation air. The basic Carrier design elim inates this problem. During mechanical cooling, all outdoor air that passes thru

the Humidry® outdoor air cooling coil is dehumidified whenever any zones require cooling. The air is then further dehumidified when it passes thru the zone module cooling coil.

If further dehumidification should be required for any or all zones, reheat can be added easily. A humidistat, installed in the conditioned space to override the thermostat, energizes the cooling coil for that zone.

Ease of service

The Zone-Mizer™ Modular Multizone uses simple, familiar, commercial, ther mostatic controls for each module, eliminating the need for factory experts and complex start-up and service procedures. The printed control circuit board has clearly marked terminals for easy connection of standard 2-stage heating and one- or 2-stage cooling thermostats, which are located in each zone.

Identical relays plug into the circuit

board. Modules can be easily combined

to serve larger spaces by placing factory-supplied jumper wires on the premarked terminals.

The entire control system is neatly organized in one location. For excellent accessibility, all circuit breakers project outside so that any motor can be dis connected without opening the highvoltage box. This often eliminates the need for separate field-supplied disconnects.

The handsome Carrier mercury bulb type thermostats control heating and cooling modes. They are available with a locking device which requires an Allen wrench for access, or you can allow the zone occupant to set his own temperature.

Access to the Zone-Mizer Modular Multizone is thru removable side panels held in place with simple fasteners. Top

panels may also be removed for com

plete access to unit interior.

In short, the local installing dealer or contractor can handle all service and will have available, from the nearest Carrier distributor, any parts required.

Accessories and factoryii'stalled options

Hot water/glycol heating (SOME) —

Often, such as when renovating existing buildings, a heating plant is available. For these applications, Carrier’s hot water/glycol heating unit may be ideally suited Each zone module has its own high-capacity heating coil All controls,

solenoid operated shutoff valves and balancing valves are included. No internal piping or wiring required.

Heaters are designed for and in tended to be operated with a glycol/ water solution of 20% minimum glycol concentration for freeze-up protection. (Factory-Installed Option).

Roof curb supports unit and frames roof openings to provide a strong,

watertight interface between unit and

roof. Galvanized, 14-gage steel, 2-piece construction minimizes installation time and costs. (Accessory)

Modulating outdoor air control pro vides year-round ventilation with out door air. An outdoor air thermostat locks out compressors to permit “free cooling” with outdoor air. (FactoryInstalled Option)

Roll filter package includes 65 ft of 2-in. thick filter media, automatic media

advance switch and a motor. The run

out switch turns on the filter light in the

remote control center to show when the media needs replacing (FactoryInstalled Option)

Powered exhaust damper has con trols to operate outdoor air fans to

exhaust return air when unit is in “free cooling” mode. (Factory-Installed Option)

Cooling only unit (SOME) — Unit is available with all heating controls but without heater assemblies. Included are 24-volt control circuits and 115-volt power terminals for 2-stage control of steam heating coils field installed in the

unit or in the zone ductwork.

Electric heat (SOME) — Each zone module is equipped with its own inde pendent heater assembly. Two- and 3-stage heat is available to provide close air temperature control without wide temperature swings associated with rapid-cycle, full-on, full-off systems.

Three heat-to-cool ratios are avail able: .75.1, 1.1 and 1.5:1 to match almost any heating load requirement.

(Factory-Installed Option)

Zone thermostat (24 volts) provides 2-stage heating and one- or 2-stage cooling for control of individual modules. Matching subbases are available with or with out tamperproof switches and automatic changeover.

(Accessory)

Remote control panel (24 volts) — This decorative

central control for the entire unit has switches for HEAT,

COOL, AUTOMATIC CHANGEOVER, OFF and DAY/NIGHT settings; dial to adjust outdoor air damper to rapidly ventilate conditioned spaces. A dirty filter warning light and knockouts for additional warning lights are also provided. (Accessory)

*hysiccd data

UNIT 48MA/50ME

Zone Modules

Nominal Cooling Capacity (tons) 15

OPERATING WEIGHT Tib)

Base Unit 48MA 3385 Base Unit SOME (with heat) 2985 Roof Curb 506

REFRIG CHARGE (lb, R-22) 28 COMPRESSOR

No. 1 Type

Cylinders. Unloaders 6 2

No. 2 Type

Cylinders (has no unloaders)

System Oil Charge (pts) Unloader Settings (psig)

Left Bank Right Bank

Capacity Steps (%) 100,67,33

OUTDOOR AIR FANS

Motor Hp .Rpm...Frame (NEMA)

Nominal Cfm

INDOOR AIR FANS

No. ...Size (in.)

Cfm (Nom) 6000 Motor Hp .Rpm Fan Pulley

Outside Diameter (in ) Bore (in.)

Fan Belt No ..Size w/Std Mtr

Motor Pulley A

OutsideDiam(in.) w/Std Mtr Bore (in.) 1-1/8

Resulting Fan Rpm w/Std Mtr 880

Motor Pulley B Outside Diam (in.) w/Std Mtr 60

Resulting Fan Rpm w/Std Mtr

OUTDOOR AIR COOLING COIL

Face Area (sq ft)

Corrugated Fins/in ...Rows

EVAPORATOR COILS (zone)

No. ...Face Area (sq ft, ea)

Corrugated Fins/in .Rows

HEATING SECTION (48MA)

Rise Range Input (1000 Btuh) Total

Bonnet Cap (1000 Btuh) Total

HEATING SECTION (SOME Electric)

Electric Heaters

No . .Elements (ea)

fiiMTNG SECWON (ici/ii*GTvcoii

Max Allowable Inlet Temp Max Allowable Flow, Each Coil

Solution Mixture Max Allowable Working Pressure

Total Internal Volume (gallons)

PRESSURE SWITCHES

Low-Pressure High-Pressure

Indoor Airflow Switch (AFS 1

Factory Setting (cfm) Adjustment Range (cfm)

INDOOR AIR FILTERS

Std No. ..Size (in )

High Efficiency (optional)

No. . Size (in )

Roll Media (optional)

OUTDOOR AIR FILTERS

No . Size (in )

No 1 No. 2 No 3

w/Opt Mtr

w/Opt Mtr w/Opt Mtr

Each Module Full Rate

Cutout Cut-in Cutout Cut-in

016 024

06DE537

— —

.... " .

— — —

16,500 15,000

2 15x15 2 15x15

5 1725

10 6

1-3/16 1-3/16

1 3V630 1 3V630

—

5 3

— — — —

—

995

—

13 2

8. .2 12 13 3

432

324

40 5

8 2 or 3

2 61

■ or 3-Stage, Nichrome, Open-Wire Flesistance Elements in Each Zone Module

8 10 10 12

20 25

3805 3405

506 32 43

06DE824

6.2 6 ..2

06DA824

100,83,67

50,33,17

8000 10,000 10,000

7-1/2 1725 10 1725 10 1725 15 1725

10 6 80 80

60 50 50

1-3/8 1-3/8 1-3/8 1-5/8 1-5/8

995

— —

1145

—

Thermostatic Expansion Valve, Hot Gas Bypass

13 2

8. .2 12 13 3

432

324

40 5 40 5 40 5 40 5

8 2or3 J_ 10 2 or 3 I 10 2 or 3 [ 12 2 or 3 |

2 61

6000

4000-600

Same but with 36 5% efficiency (NBS Dust Spot Test)

2 20 X 25 X 1

028 030 034 040

4075 3665

506

Reciprocating Hermetic. 1725 Rpm

06DE537 06DA824 06DA537 06DA537

6 6

22 22 21

Compressor No 1 Only 71 0 ± 1 5 57 5 ±25 760 ± 1 5 62 5 ±25

100,80,60

40,20

Propeller, Direct Drive

1 1075 56(1-phase)

1 1140 56 (3-phase)

15,000

Centrifugal; Belt Drive

2 15x15 2.15x15 3..15x9 3. .15 X 9

1-3/16

2 3V560

—

Factory Installed

1095

Shipped With Unit

1230 1230 1230 1230

—

6 8

13 2 13 2 i

Solenoid Valve and Capillary Tube for each

I 10.212 I 10.212 I

Furnace Assembly in Each Zone Module

25 F to 55 F at 0 75 in wg ESP

540

405

One Heating Coil in Each Zone Module

3 15 3 15 3 76 3 76

65 ft of 2-in media

6 8

13 3 j 13 3

200 F

6 Gpm

20% Glycol

30 Psig

29 + 5 Psig

39 ± 5 Psig 400 ± 5 Psig 300 ± 5 Psig

12 20 x 25 x2

28 30

4080 3670 4400 5250

506 43

06DE537

6.2

100,80,60

40,20

15,000

1-3/16

2 3V560

—

1095

—

5 6 5 6

—

540

405

4800

630 57 66 1

06DE537 06EE250

6.2 6

75 5 ± 1 5 58 0 ± 2 5

100,83,67

50,33,17

1.1140 56 (3-phase)

24,000

12,000

20 1725

8.0

1-11/16 1-11/16 2 3V630 2 3V630 3 3V670

6.0

1095 1320

6 5

1425

102

13 2

12.201 12 3

648

486

9000

6000-9000

2 32 X 35 X 1

12 37

5700

630

4.1

06EA250

—

100,75,

50,25

23,000

12,000 15 1725 20 1725

3 3V670

6.0

1095 1320

6 5

1425

102

13 3

12.201 15 3

648

486

40 5

12 2or3

Roof curb dimensions (48MA)

COMPRESSOR, CONDENSER AND CONTROL BOX END ' OF UNIT

Certified dimension drawings available on request.

UNIT

48MA 1

016,024,028,030

034,040 i

A 1 B

]B- 2% Î 7-3

21-1 r/j 1 7-ll-y<

48MA0M. 040 02 ZONE)

ZONE MODULE END

CURB DETAIL

I c

1 D

i n-9 Î 14-iy

DiMENSiONS (ft-in.)

i........E

.5-6 V,

6-7’/,,

......

i 7-2% i 8-4%,

MAIN GAS l3 FPT CONN ON SASE UNIT

evaporator (ZONE MODULE ¡AIRFLOW

* NOT USED ON 48MA0t6,024(8 ZONE

NOTES- I FOR additional INFORMATION SEE

; F

Î 1-10%, Î 2- 9% j 3-1

module UNITS)

BASE UNIT PH.YSICAL DATA AND DIMENSIONS

2 MAXIMUM ALLOWABLE UNIT PITCH IS

jlN IN lOFT IN ANY DIRECTION

3 REMOVE SHIPPING BRACE BEFORE

ASSEMBLING CURS SECTION (LOCATION SHOWN).

i G

i H

1 2-2%, I 6-0%

! 6-8% i 0-10%,

'6'.4|"4SMA028,

'030 (10 ZONE MODULES) 5'-r 48MA016, 024

(8 ZONE MODULES)

1 J 1 C- 7%

Base unit dimensions (48MA)

Certified diiTiension drawings avaiiabie on request

UNIT

48MA

016,024, 028,030

034,040

*Ovsra!i height: induces 1 3/4-in for fan guards WSMA034 an.d 040

i A 1 7- 21^ 1 7-n

_______

i B I c f

----------------

I 3-0%

“T

-----------------

; 21 - 9%«

; 0

1 2-2*%s

1 4-2

DIMENSIONS (ft-

1 !3-5% i i3-5%

! 1 0- 9^6

in.)

1 G i 2-10

i 3- 4%s

1 ” 1 7-3%« r /«

I 8-6% 1 0-3

i ■)

0-3%

0-7%

Base unit dimensions (SOME)

BASE UNfT SOME

CONO£NS£R AIR INLET

^ GRILLES ON UNITS

034,040 UNIT POWER SUPPLY 24" KO IN BOTTOM OF UN!T CONTROL SOX (EXCLUDES HEATERS)

034, 040

• CONDENSER AIRFLOW

notes: I SPACE REQUiRED FOR SERVICE

AND AIR FLOW ALL AROUND AND ABOVE UNIT IS 36 iN.

2 FOR ADDITIONAL INFORMATION

SEE ACCESSORY ROOF CURS

DIMENSIONS.

3 CENTER OF gravity IS WITHIN

6IN RADIUS OF GEOMETRIC CENTER OF UNIT

4 MAXIMUM allowable PITCH OF

UNIT IS -¿-IN. IN lOFT IN ANY DIRECTION.

UNIT

SOME

016,024.028.030

034,040

^■Overaü r.eigdt, inciudes ' 3/4 in fc* fan guajds .(oOV-ЕОЗА and 0^0).

7- 2% 7-1 i

i ®

: 3-0^«

i 3-9”/.** 21- 9Мб i 4-2% ! 13-54 i

DIMENSIONS (ft-in.)

j 2-2^5<* 1 13-54 i

c i D . j E i

ELECTRIC RESISTANCE HEATERS MAIN POWER

_______

ELECTRIC resistance

CONN. 4|" KO

: Я

i 0-2‘4б

T| heaters main POWER

Certifiées dimensior> drawir^gs avaueble ori request.

3-74* i 7-34* i 0-34 4-4 г 8-64

i J i 0-34 i 0-74

Roof curb dimensions (SOME)

COMPSeSSOR, CONDENSER AND CONTROL SOX END

OF UNIT

Certified dimension drawings available on request

--------------------------—J

------------

UNIT 1 48MA A

016,024,028,030 1 IS- 2%

034,040 j 2i-n%

ELECTRIC resistance HEATER POWER

Ag'KO ON UNIT

) GLYCOL CONN

-10Й SUPPLY’

I г"РРТ ON UNIT

DIMENSIONS {ft-in

В {

7- 3 !

n-9

i D i E i F

i S-6% 1 7-2% 1

7-11% : ;4-l% i 6-7%« i 8-4%« j

5' 50ME0I6.024

ЮЙ' SUPPLY GLYCOL CONN

2"PPT ON UNIT

if) evaporator (ZONE module; AIRP'lOW

* not used on 5CWE0I6,024(820NE

NOTES- 1 POR ADDITIONAL INFORMATION SEE

module UNITS)

BASE UNIT PHYSICAL DATA AND DIMENSIONS

Z MAXIMUM ALLOWABLE UNIT PITCH IS

■jlN IN ЮРТ IN ANY DIRECTION.

3. REMOVE SHIPPING BRACE BEFORE ASSEMBLING CURB SECTION (LOCATION SHOV/N)

)

i G

i H 1-10%« i 6-0% 2- 9%

iilL

i 6-8%

030 OOZONE

MODULES)

¡8 ZONE

MODULES)

] J

I 0- 7%

i 0-10%«

Selection procedure (with example)

Refer to Carrier’s Engineering Guide for Multizone Unit Systems and contents of this booklet for typical multizone design considerations. Using the Engineering Guide, cal culate cooling and heating load estimates for the areas to be served by the multizone unit. Divide each area into zones based on the peak load and control requirements within the area.

The resulting loads calculated for a typical building are;

Cooling Grand Total Load (GTL)

........................................

272,440 Btuh

Sensible Load (SL) .................................................. 219,000 Btuh

Room Design .................................................... 75 F db/50% Rh

Outdoor Air (OA) Cfm............................................................1000

OA Ambient Temperature

..............................

95 F db/75 F wb

Electric Power Source...................................................... 460/3/60

Zone No. (RTL)/Zone (RSL)/Zone

1 19,000 Btuh 16,935 Btuh

2 25,000 Btuh 22,505 Btuh

3 25,000 Btuh 22,505 Btuh

4 70,000 Btuh 59,160 Btuh

5 22,000 Btuh 19,720 Btuh 6 25,000 Btuh 22,505 Btuh

7 40,000 Btuh 33,870 Btuh

Total 226,000 Btuh 197,200 Btuh

*Loads are peak loads

Room Total Load* Room Sensible Load

Heating (Electric Resistance Heat required)

Zone No. Heating Load/Zone Electric Resistance/Zone

1 34,000 Btuh 10 0 kw

2 44,000 Btuh 12 9 kw

3 44,000 Btuh 12 9 kw 4 111,000 Btuh 32 5 kw 5 42,000 Btuh 12.3 kw 6 44,000 Btuh 12 9 kw

7 81,000 Btuh 23 7 kw

Total* 400,000 Btuh 117 2 kw

*Zone Peak Capacities

Selection: Base the multizone unit selection on cooling load require

ments. Enter the 48MA/50ME rating tables in the Per

formance Data Section and select the unit that meets or exceeds the grand total load at the specified conditions. (Interpolation may be necessary to obtain unit rating at certain conditions; extrapolations are not advised. Contact Carrier Application Engineering tor performance data at points beyond the range of published tables.) Tbe 024 size unit does not have sufficient capacity to meet load requirements at any cfm. The 028 size exceeds load require ments; however, it is the smallest unit that meets specifica tions. Thus, the 48MA/50ME028at: 9000 cfm; 1000 cfm OA; 95 F/75 OA temperature; and 75 F/50% Rh room design has a Total Capacity (TC) of 282,000 Btuh, Sensible Heat Ca pacity (SHC) of 219,000 Btuh and a compressor kw of 27.5. Calculate the Room Total Capacity (RTC) and the Room Sensible Heat Capacity (RSHC) by deducting the outdoor air load from the unit capacity. The outdoor air load with respect to room conditions is:

Total Heat (OATH) = 4.5 (hoa - hroom) (OA cfm)

= 4.5 (38.61 - 28.29) (1000) = 46,440 Btuh

Sensible Heat (OASH)

- 1.09 (toa - troom) (OA cfm) = 1.09 (95 - 75) (1000) = 21,800 Btuh

The unit capacity available to offset room loads is:

RoomTC = UnitTC - Outdoor Air TC

= 282,000 - 46,440 = 235,560 Btuh

Room SHC = Unit SHC - Outdoor Air Sensible Heat

= 219,000 - 21,800 = 197,200 Btuh

For comparison.

Actual Load

GTL = 272,440 Btuh SL = 219,000 Btuh RTL = 226,000 Btuh RSL = 197,200 Btuh

Actual Unit Capacity

TC = 282,000 Btuh SHC = 219,000 Btuh RTC = 235,560 Btuh RSHC = 197,200 Btuh

The 48MA/50ME size meets or exceeds the total and zone load requirements at the specified conditions. The excess RTC decreases space average relative humidity slightly below the room design of 50%. By increasing air quantity above 9000 cfm, this excess latent capacity can be converted to additional sensible capacity if desired.

Since the modular multizone is a constant volume machine, proportion the selected supply cfm per zone to satisfy each zone’s peak load condition.

Divide room sensible capacities (RSC) equally among the modules if an equal cfm is going to each. In this example, the 48MA/50ME028 has 10 modules and the nominal cfm is 900 cfm per module and equal cfm’s are not going to each.

Vary the cfm to each zone (with field-supplied manual

dampers in zone ducts) to match different zone require ments. Since the original rating was based on 9000 cfm supply air, all variations must total 9000 cfm. When the cfm

is changed (by some percent) from the nominal in a specific

module, use the room capacity multipliers in the Zone Cooling Capacity Multiplier Table to correct room TC and room SHC for that zone. Capacity versus cfm changes for the example is given in the Capacity vs Cfm Change table.

By analyzing each zone’s ratio of deviation from equal

sensible heat allocation, determine the proper cfm change. In the example, if building room SHC is 197,200 Btuh and

10 zones are used, each zone’s normal room SHC is 19,720 Btuh. But if Zone 3 has 22,505 Btuh room SHC, then

by ratio of 22,505: 19,720 or 1.14, the cfm change is +20%.

Correspondingly, if Zone 1 had 16,935 Btuh room SHC,

the cfm change is -20%.

In applications where the zone selection is not an incre

ment of the number of unit modules (i.e. one zone requiring 500 cfm in a 48MA/50ME028 with 10,000 cfm), refer to Module Cfm Limits (page 36), Application Data section for details on using cfm’s below 600 cfm/module.

Formulas required to use ratings are:

Outdoor Air Total Heat (OATH)

OATH = 4.5 (OA cfm) (hoa - hroom)

CAPACITY VS CFM CHANGES

ZONE

NO.

NO. OF RSL/ZONE

MODULES

...

1 2 3 1 4

RSHC — Room Sensible Heat Capacity RSL —

10 197,200

PEAK LOAD (RSL/NOM UNIT RSHC) FROM NOMINAL UNIT RTC

1 16,935 1 22,505 22,505/19,720

3 59,160 1 1 22,505 2 33,870

22,505

19,720

22,505/19,720 59,160/3 X 19,720 =

22,505/19,720 1 .14 : +20 1080 1 11 33,870/2 X 19,720 =

% DEVIATION

16,935/19,720

19,720/19,720

.86*

1.14 1 .14 1 00

1.00

Room Sensible Load

ZONE COOLING CAPACITY MULTIPLIERS

CFM CHANGE*

+ 35

+ 20

+ 10

-10

-20

-35

*Must not be greater than 1200 cfm nor less than 600 cfm per module, tlf resulting RSHC is greater than RTC, then RSHC equals RTC

ROOM TOTAL

CAPACITY

(RTC)

1.15

1.10

1.05

1.00

0 95

0 90

0 85

ROOM SENSIBLE

HEAT CAPACITY

(RSHC)

1.14t 1 07t

1.00

0 93

0.86

0.79

Outdoor Air Sensible Heat (OASH)

OASH = 1.09 (OA cfm) (toa - troom)

Room Total Capacity (RTC)

RTC = Unit TC - OATH

Room Sensible Heat Capacity (RSHC)

RSHC = Unit SHC - OASH

Leaving Air Temperature (LAT)

TAT + + RSHC

LAT = room temperature - ^ Q'^f^

Determine Heating Capacity:

The specified requirement for electric heat dictates the

selection of a 50ME028 unit with a kw option that meets

or exceeds the heating load.

The Electric Resistance Heater Data table (page 30) indi cates that the 028 unit has heating capacity options of 66, 88 and 132 kw. The 132 kw option is selected as it provides adequate heat for this application. The kw/zone and number of heat stages available are:

Zone No. Load

3 4 5 6 7

Total

10.0 12 9 kw 12 9 kw 32 5 12 3 kw 13.2 kw 12 9 23 7

117 2 kw 132 0 kw

Zone Heating

Capacity

kw kw 26.4 kw 6

13 2 kw 3 13 2 kw 3 13 2 kw 3 39 6 kw 9

31 2 kw

Stages

of Heat

3 3

% CFM CHANGE

-20 720 i 9 +20 +20 1080 1 11

0 0 900 ! 1 .0

-20 1440 1 .9

Stages of heat are controlled individually in the small zones or collectively in large zones to provide flexible and continuous control for each zone.

Determine fan requirements

For 48MA/50ME operation, cfm range per module is 600 to 1200 cfm. Lower flow volumes are permissible if only first stage of heat is operated. Volumes above 1200 cfm may cause water blow-off during cooling.

Since the various unit zones operate at different air quantities and different external resistances, identify the zone having the highest static pressure requirement for the supply duct and supply outlet.

Usually, the longest duct run to the last outlet, with the greatest number of offsets and elbows, has the greatest static pressure requirement. Assume a duct friction analysis has been made and the cfm and static pressure are:

Zone No. CFM

The total unit (02810or 030) cfm is 9000. Zones 4 and 7 have 3 and 2 modules, respectively, “ganged” together to comply with the limitation of 1200 cfm per module

The cfm for Zone 2 is 1080 with an ESP of 0.8 in. wg. This module appears to possess the highest friction loss. There fore, the main fan static pressure is established at 8 in. wg ESP.

Enter Fan Performance table at 9000 cfm, .8 in. wg ESP and read: 1020 rpm and 5.4 bhp. The 028 indoor fan motor data shows the standard 10 hp motor with a maximum bhp of 11.5. Therefore, 5 4 bhp for this selection is satisfactory.

In the Physical Data table, 2 pulley selections are available with the 028: Pulley A, shipped mounted; Pulley B, shipped in the blower compartment. Pulley A has a fixed pitch and at 1095 rpm is close enough to the required cfm and should be used. Pulley B at 1230 rpm allows selection of the unit at higher cfm’s and static pressures.

jUNIT TOTAL

CFM3 CAPACITY

Imultiplier

1080

2700 i 1 0

9000 j

RTC — Room Total Capacity

ESP (in. wg)

1 2 1080

3 1080

4 2700 5 6 7

Totals 9000

720

900 1080 1440

UNIT

NOMINAL

RTC/ZONE

23,556

3 X 23,556

23,556

2 X 23,556

No. Modules CFM/Module

8 5 6 4 4 5

1 3

ADJUSTED

21,200 25,912 25,912 70,668 23,556

25,912

42,400

235,560

720 1080 1080

900 900

1080

720

Performance data

Room Design 75 F/50% Rh

OUTDOOR

100

105

115

OUTDOOR

TEMP

Db Wb

65 204

70 204

65 70

73 75

75 78 80

100

75 78

105

110

78 183 133

115 75

0 750

TC SHC Kw

168

168 J18

65 164

164

164 116

75 164 116 65

I6U

160 114

160 114 16 0 173 121 16 6

160 114 16 0 175

160 114

156 112

156

156 112 16 5 171

70 152 75

152 no 17.0

148

144 107 18 0

TC SHC Kw TC

200 141 200 141 200 141 200 141

196 140 196 140 196 196 196 140

192 137 192

192 137

187 1 35 20 9 187

178 131 22 3 191 155 23 3 200

14 8 174

118

14.8

116 15 4 169 116 15 4 173

15 4 176 15 4

114

16 b 16 0 169 126 16 4

16.0 16 5"^

112 16 5 168 123 17 2

no 17 0 160 130 17 5

109

17 5

143

18 0

143

18.0

18 8 208 155 19 2 18 8 18 8 18 8

19 5 203 157

19 5

140 19 5 212 140 19 5

19 5 20 2

137 20 2 207 150 21 2 216

20 2 209 147

135 20 9 201

21 6

4,000

Outdoor Air Cfm

TC SHC Kw

126 15 1

178 122

177

165 131

177 116 164

164 161 124 155

Outdoor Air Cfm

212 217

212 215 216 146

207 214

216 202

197

199 150 22 8

15.3 184

129

15 7 172

124

15 9 179 131 121 16 0 119 16 1

16 2

118 16 8 186

16 9 128 17 0

120 17.4

125 17 8 172

18 5 171 139 19 1 154 130

18 8 162 152

5,000

750

SHC Kw 153 18 5 216 161 18 7

149

18 7

151 19 5 219 148 19 6

19 7 227

19 9

153

20 2 148 20 5 222 154 145 20 6 143 20 8 230

155 20 9 209

21 4 221 154

157 21 6 204 152

21 9 211 166

1500

177 134 15 2

183 125 186 121

168 174 137 16 7 182 127 17 1 167

189 170 143

177 133 17 7 163 124 181 127 18 0 163 124 16 9

165 149 17 9

TC SHC

224 212 167

224 152 20 1 210 159

208 173 20 2 206 157 214

227

210 166 23 6

SHC

15 6

124

15 8

140

16 2 16 4 16 5

146 16 4

17 4

121 116 17 5 167

17 3

139 18 3 158 123 17 4

19 4

1500

19 1 215 161

152

19 4 210 159 19 3

158 19 9 210 159 148 20 3 210

164

20 6

21 1 148 21 4 144

21 6 170 21 3 201

160

21 8

22 1 176

22 1

22 6

24 0 186 149

178

SHC Kw

130

176

130

171

128 15 8

171

128 15 8

171

128

171

128

167 126 167 126

126

167 126

126

163 124

158 123 17 4

121

149 119

SHC Kw

215 161

206 206 206 206

201 201

196 196

191

18 6 222 18 6

19 3 19 3

159 19 3

20 1 157 20 1 157

20 1 220 1 66 21 0 229 157 20 1 157 20 1

155 20 8 211 172 21 5 155 20 8 214 155

20 8 217 153

21 5

153 21 5 151

22 2 206 168 23 3 22 9

COOLING CAPACITIES

TOTAL UNIT CFM

5,000

Outdoor Air Cfm

750

SHC K w TC SHC

15 2

181 139 15 4 184 146 15 6 181 142 15 4 186

15.2 184 134 176

179 136 16 2

15 8 182 133 15 8

183

16 3

172

16 3

175 138 16 8

16 3

178 133 16 9 186 139

16 3

180 130 17 1

16 3

182 128 17 2

16 9

170

16 9

173 136 17 5 175 132 17 6

165 143 17 9 168 138 18 1 175 152 18 5

17 9 166 137 18 4

159

TOTAL UNIT CFM

Outdoor Air Cfm

226 167 19 2 218

221 169 20 0 227 176 223 225

213

216 222 163 21 1

224

205 209

TW 173" 23 8 206

15 6 190 137 15 9

141

16 0 179 152 16 2 176 140 16 0

16 3

131

16 4 191 133 16 8 176

143 16 6 174 158 16 7

141

17 3

18 7 - - -

142 19 1

6,500

750

SHC Kw

171

19"0 226

173 19 8

166

20 1

164

20 2 234 166

175 20 5 171

20 7 222 182

160

21 2 236 162 21 9 212 174 20 5

21 7

168 164 21 9

174

22 2 212 193

169

22 4 217 184

1500 0

Kw TC SHC Kw

181 142

185 143 188

180 149 17 0 190 133 17 6

175 155 17 6 181

170 162 18 2

TC SHC Kw TC SHC Kw

233 170 19 5 222 178 19 0 222 Tss 2b"b 2i7 i76" T9" 7

231

217

233

217 223 227 172

215 184 24 0 197

16 4 176 140 16 0

137 16 6

- -

146 17 9 167

- - -

- -

1500

179

170

191 172 21 5 212 174 20 5

166

188 178

T95" TTT" 191

176

140 16 0 140

172

138

172

138

172

17 4

19 2

20 3 20 6 20 7

20 8

21 1 21 7

21 8 22 2 22 5

22 6 23 0 202 169 21 9

138

172

138 16 6 184

172

138

167 136

136

167 136 17 2

162 134 162 134 17 7

158 132 is 2 T69 153 130 18 7

222

178

217 176 217 176 217 176 19 7

212 174 212 174

212 174 20 5

207

172 21 2 216'

207

172 21 2 220

207 172 21 2 202

169 21 9

167 22 6 f65 23"3 202

15.4

16 0 16 6

16 6 16 6

16 6

\17 l74

17 2

T7T T69 154^

Outdoor A r Cfm

19 0"

229"

232

224 19 7 227 19 7 229

231 20 5 219

20 5

222 187

225

228 179

229 177

222 181 22 2 "2ll

214

210

48MA/50ME016

6,000

Outdoor Air Cfm

750

TC SHC

189 146 15 8 194 181

184 186 187

176 179 150 182

185

177 179 144 17 8

172

162 153‘

150 15 7

152 ibb 183 1641 148 145 143

155 145 17.1 189

142 17 2 140

152 147

149 18 3

T48

TC 188

16 4

189 155

16 5

192 149

16 6

194 178 170

16.8 183

17.0

17 3 17 5

178 '167

17 7

'18‘T 17l3 173

TF9

19 3

48MA/50ME024

8,000

750

SHC i 88"

183 l"90"

185 182 181

191 20 9 182 21 3 233 189

189" 184 22 0 227

19T 186 22 8

185 23 6 T89

19 4

233" 196 19""6

19 5

239 187 19 9

20 1

228 202 20 3 233 20 4

237 187 20 8 20 5 239

223 207 21 1 227

21 4 21 5 - -

21 8 222

22 5"

"21 7 210"

221

24 1

1500

SHC

T58^

149

145

161 151

- -

__ _

- -

1500

SHC

20 4"

193 20 6 183 21 0

21 2

199 21 4

21 8

204

22 2

195 22 5

- - 22 9

201 23 3

_ _ _

- -

15^8' 26 1

T6^4'

16.6 16 8 16 9

T7V0 17 2 17 5

T7 8

18 4

AIR

TFMP Db

95 75

100

lO*'

lis

TC SHC Kw

265

70 65

70 73 259 75 259

65 254 70

78 80

70 248 182 75 78

70 75 242

78 75

190 24 6

265

190

259

188 24 9

259 188 24 9 274

188 24 9 277 188

185

254

185

254

185

254

185 25 8

254

185 25 8 279

248 182 26 7 266 248 182

242

180 27 6 180 27 6 259 201

236

177

230 174

—

24 0

24 9 279 25 8

25 8 25 8

26 7 261 205 27 6

26.7

28 4 29 2

7,000

Outdoor Air Cfm

1000

SHC Kw

203

275 280 197

269

206

200 25 8 282

196 25 9 193 26 1

262

208 26 4

267

202 26 7 273 196 276

192

189 27.3 294

198 27 9 277 212

269 194 254

207 28 4 261

256

199

246

206

2000 0

24 6 24 8 289

25 5 273

27 0 284 27 2 290 196

28.1 283

28 8 270 220 29 5 252 29 9 268 219 30 4 256 236 31 2

SHC

280 213

201 25 3 277 221 25 7 271

209 26 2 271

287

201 26 5 271 210

291 196 267 229

275 217

204 27 7 264 190 28 3

268 225

203 233

24 8

277

271

26 7

264

26 6

264

27 1

264

28 0

264 258

28 0 28 6 258

29.0

258 252 202

28 9

245 199

30 8

239

TOTAL UNIT CFM

9,000

Outdoor A ir Cfm

1000 2000

SHC Kw

213 24 6 213 24 6

210 210 25 6

210 ToT 26 5

208 26 5 208 208 26 5 208

205 27 4 205 205

202

197

TC SHC K w

287 226 25 2 291 220

25 6 280 229 26 1 284 244

284 25 6 287 219 26 5 25 6

289

273

277 225 27 3 284 26 5

282

285

26.5 287 212 27.8

270 228 27 4

275 221 28 5 284 235 29 1

27.4

277 217 28.6 28 3 263 230 29 0

28 3 267 29 1

263 29 9

253

25 4

223

26 3 291

216 26 6

27 0 277

231 219 27 5

214

27 7 297 219 28 4

28 2

224 29 3 276 222

30 4 - -

229 31 0 262

— — —

SHC

291 236 298 224 25 8 285 234

296 225 27 0 278 232 26 0 299 219 27 2 278 232

292 227 28 1

276

- - -

269 255 29 5

25 4

26 3 278 232 26 0

232 26 7 278

252 27 2 240 27 7

248

28 6

243 30 0 258 223

258 31 7

—

Kw TC

SHC

285 234

232

272 229 26 9 272 229 26 9 272 229 26 9 272 229 26 9 272

229 26.9 292

265 226 27 8 276 265 226

226

265 258 223 28.7 269

221 29 6

251

245 218 30 3

25 1 294 25 1

26 0 291

26.0 295

27 8 27 8

28 7 273

48MA/50ME028

11,000

Outdoor Air Cfm

1000

298 242 25 8 287

293 241 26 9

280 284 288 291

280 243 283 239

268 243 258 250 31 4

SHC

25 6

248

"26 5

"250"

244 26 7

27 0

238

27 4

252

27 7

247

27 9

240 236 28 1 233 28 2

249 28 6

28 8 29 0

"29 5

252

29 7

245

30 8

2000

SHC Kw

"298 "258 25 s'

305 246 26 1

"266 26 '7 297 254 302 304 241

"283

290

282 "269

274 274

27 1

246

27 3 27 5

273 27 6 262 28 0

28 9

29 8

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