Carrier 39E/ER User Manual download pdf

HEATING & COOLING

39E/ER

Fan Motors and Drives

Application Data

Fan Motors and Drives for Central Station Air-Handling Units

60 Hertz

INTRODUCTION

The same careful attention given to the selection of the

fan should be afforded to the selection of the fan motor

and drive. It is the purpose of this publication to define

the major factors involved in the selection procedures for

these most important components

Factory Installed or Field Supplied? — This

decision is a very basic and important one. Basic, in that it

needs to be made early, in the ordering phase of the job.

Important, in that the results of the motor and drive

selection directly affect the satisfactory performance and

economical operation of the equipment selected.

Limitations — Every fan has limitations relating to

maximum speed and shaft horsepower. Refer to Table 1

for maximum fan horsepower and fan speed limits on

standard 39E/ER air handlers.

Fixed or Variable? — Fixed drives are recommended

for all applications. However, variable pitch drives are

often specified because they permit fan speed (thus, sys

tem air volume) to be easily field adjusted. Unfortunately,

this advantage is usually offset by balancing problems

inherent in their design that cause vibration and prema

ture belt wear, especially in the higher horsepower drives.

For this reason, variable pilch drives with motors larger

than 25 hp are not recommended and are not available

from the factbrv.

NOTE: In the event that such a field-supplied drive

proves unsatisfactory, contact the drive supplier for any

additional technical assistance required

Service Factor — Almost all drives are subject to

occasional overload, consequently it is good engineering

practice to have ample capacity designed into the drive to

take care of these overloads. Although higher service

factors will extend the belt life, they will also increase the

drive loss, resulting in reduced energy efficiency. A

reasonable service factor for fans is considered to be

1.2 to 1.5.

Drive Loss — Proper allowance should be made so the

motor selected does not run overloaded. The major

factors in drive efficiency are the load on the belt and the

bending radius of the belt around the pulley. Belt tension,

operating temperature and drive alignment also con

tribute to drive losses. Considering these factors, the

drive loss is generally between 2 to 6% of the maximum

fan brake horsepower. Using a 3% selection allowance is

reasonable.

Motor Speed — Generally, 1800-rpm motors are used

on 39E Series air handlers, All factory-supplied standard

drives are designed for 1800 rpm, except for some smaller

airfoil units that require 3600-rpm motors due to space

limitations. Larger motors in certain size units may

require an optional (L5) cabinet extension.

Table 2 gives a complete summary of standard motor

sizes, limitations, and speeds. Tables 3 dnd 4 give a com

plete summary of space and sheave limitations of all fan

unit sizes with all NEMA standard motors.

Open Drip Proof (ODP) or Totally Enclosed

Fan-Cooled (TEFC) Motors(Fig. 1) — ODP motors

are recommended. Compared to TEFC motors, ODP

motors are less expensive, have a higher service factor

and are normally more readily available from vendor

stock.

The 39E/ ER motors are mounted in the unit airstream

and operate with cool air passing over the motor. This

provides additional cooling to windings and motor bear

ings and increases the life of the motor, thereby reducing

the need for a TEFC motor.

The ODP motors have ventilation openings that allow

air over and around the motor windings to keep the

temperature as low as possible.

The TEFC motors utilize an internal fan to cool the

motor windings. They do not have any openings for venti

lation air.

Totally enclosed air over (TEAO) motors rely on

strictly unit airflow to cool the motor windings. They do

not have an internal fan or openings for ventilation air.

Voltage — The nominal power system voltage will

normally be more than the motor nameplate voltage.

NEMA standards are as follows:

Nominal Power System

Voltage

208

240

480

600

Motor Nameplate

Voltage

200

230

460

575

Field-Installed Inverters — High-efficiency motors

are recommended whenever an inverter is field installed

to control fan speed. High-efficiency motors can handle

the extra heat generated much better than standard

motors. The projected life of the motor when controlled

by an inverter will be improved if a high-efficiency motor

is used.

Manufacturer reserves the right to discontinue, or change at any time, specifications or designs without notice and without incurring obligations.

Book 13 PC201 Catalog No 513-907 PrintedinUSA Form 39E-15XA Pg 1 4-89 Replaces: 39E-12XA

Tab 1b

1 2 ... 15

Summary of Contents

Page 1 - Application Data

HEATING & COOLING39E/ERFan Motors and DrivesApplication DataFan Motors and Drives for Central Station Air-Handling Units60 HertzINTRODUCTIONThe sa

Page 2 - FACTORY-SUPPLIED DTilVES

AIRFOIL WHEELTable 5 — Allowable Centerline Distance (in.) (cont)AIRFOIL WHEEL — MODUDRIVE UNITSNOTE: Allow for belt installation, initial tensioning

Page 3

APPLICATION CONSIDERATIONSTable 6 — Motor Mounting DesignationHeat Gain from Electrical Motors — Some misconceptions exist regarding the h

Page 4

Table 8 — Typical Performance High Efficiency1800 Rpm Motors at 460 VoltsTable 10 — Typical Performance ODP, 2-Speed MotorsHP FRAMEODPTEFCFullLoadAmps

Page 5

Table 11 — Typical Performance — TEFC,2-Speed MotorsTable 12 — Typical Motor WeightsRATEDHPFRAME1/.25143T1.8/.751.121.5/.37145T1.95/.851’/2.192/.5145T

Page 6

Multi-SpG6d Motors of high efficiency can provide an even greater savings in operating costs in certain applications. Typical of these would be

Page 7

Manufacturer reserves the right to discontinue, or change at any time, specifications or designs without notice and without incurring obligations.Book

Page 8 - VA 10 38% VA 10

FACTORY-SUPPLIED DTilVESFactory-Supplied Standard Drives are available for the motors shown in Table 2, in the rpm range defined by the minimum-ma

Page 9 - FORWARD-CURVED WHEEL

FACTORY-SUPPLIED DRIVE SELECTION PROCEDURE1. Obtain your fan speed and brake horsepower requirements from the fan data in Catalog 39E-10P or from the

Page 10 - AIRFOIL WHEEL

Table 2 — Motor Hp Limitations and Fan Speed Ranges for Factory Supplied Standard Drives39E/ERSIZESEELEGENDMOTORHPFRAMESIZEVARIABLEFIXEDFCAF FCAFMin M

Page 11

Table 2 — Motor Hp Limitations and Fan Speed Ranges for Factory Supplied Standard Drives (cent)39E/ERSIZESEE MOTOR LEGENDFRAMEHPSIZEVARIABLEFIXEDFCAFF

Page 12 - I'h

Table 3 — Maximum Physical Motor Frame Size andMaximum Allowable Sheave Width (in.) — Forward-Curved FanMOTOR FRAMEUNITIGV145T182T184T213T215T 254T256

Page 13 - 2-Speed Motors

Table 4 — Maximum Physical Motor Frame Size andMaximum Allowable Sheave Width (in.) — Airfoil FansMOTOR FRAMEUNITIGV145T182T184T213T215T254T 256T284TS

Page 14

MAX ROOM FOR MOTOR a SHEAVE IN UNITMOTOROPENDRIP PROOFTOTALLY ENCLOSED, FAN COOLEDFrameShaftDiameter (in.)CmaxNW RCmaxNWR145T %12”/,62'74 3’72 13

Page 15

FORWARD-CURVED WHEELTable 5 — Allowable Centerline Distance (in.)UNIT SIZE 08 111317 19232936394857FAN SHAFT DIAMETER (in.)T /i6 T /,6IV ,6IV ,5 I V,6

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