Carrier 39E/ER - Manual (Page 8)

MAX ROOM FOR
MOTOR a SHEAVE
IN UNIT
MOTOR
OPEN
DRIP PROOF
TOTALLY
ENCLOSED,
FAN COOLED
Frame
Shaft
Diameter (in.) C max
NW R C max
NW R
145T % 12”/, 6 2'74 3’72 13'72 2'/4 3'72
182T 14'/8 2% 4'72 15"/,6 2% 4'72
184T 14'/8 2% 4'72 16”/, 6 2% 4’7a
213T 15% 3% 5'74 18=/,6 3=/a 5'74
215T 17% 3% 5% 19”/,6 3% 5'74
254T
20y,6 4 6'74 23'7a 4 6'74
256T 22V,6 4 6'74 24% 4 6'74
284T 23V,6 4=7e 7 26=/e 4=/6 7
286T 24’V,6 4=7a 7 27”/6 4=78 7
324T 26 5'74 8 28% 5'74 8
326T 2 V k 5'74 8 30'/4 5’74 8
364T 28=78 5% 9 32'/2 5% 9
365T 29”/,6 5% 9 34'7 b 5% 9
404T 32=78 V h 10 37'/4 7 'A 10
405T 34'78 V A 10 38% V A 10
Fig. 1 — Physical Data, Motor and Drive Dimensions
ADVANTAGES OF INTERNALLY-MOUNTED,
FACTORY-INSTALLED MOTORS
Motor is Protected from Shipping and Storage
Damage — Unlike the externally-mounted factory-
installed motor, the internally-mounted motor and drive
are protected against damage and vandalism during ship­
ping and jobsite storage. At start-up time, the unit
requires only final drive tightening to be ready for
operation.
Largest Possible Motor May Be Factory In­
stalled
— Externally-mounted motors can cause stress
on the top of the fan section when cantilevered from the
unit side casing panels thus limiting motor size. The
internally-mounted motor is always mounted on a base
located in the bottom of the fan section. This base is
designed to support the weight of the largest (heaviest)
motor that is compatible with a particular size unit.
Provides Longer Motor Life — Externally-
mounted motors are often subjected to less than ideal
ambient conditions that may contain dust or other air­
borne particles. Because internally-mounted motor is in
airstream, the standard practice of using filters in the
airstream (often higher efficiency filters) insures that
clean filtered air passes over motor.
Increased Motor Service Factor — The service
factor is the amount of continuous overload the motor
can withstand without damaging the motor or decreas­
ing design life. The lower the operating temperature of
the motor, the longer the life of the motor.
The standard 1.15 service factor applied to integral
frame open drip proof (ODP) motors and the 1.0 service
factor applied to totally enclosed, fan-cooled (TEFC)
motors are based on operation in an ambient temperature
of 104F (40C).
The motor mounted in the airstream operates at a
lower temperature than if mounted externally due to the
cool, fast moving air passing over the motor As a result,
motor life is extended. In cases where there is warm circu­
lating air, the motor still runs at a lower temperature
than if externally mounted due to the improved heat
dissipating effect of the air passing over the motor.
Factory-supplied and installed motors have Class B
insulation as standard for use in applications where
motor is subjected to maximum ambient temperature of
104 F (40 C). When the motor will be subjected to higher
temperatures, either from ambient temperature or high
temperature heating applications, a special order motor
with Class F insulation should be used