TERMINOLOGY
GUIDE
The following selection
guide is designed to help you determine the correct
motor for your application. It is written in
general terms and is intended only as an aid.
The customer is solely responsible for the motor
performance and suitability in applications for
their use.
No application fitness approval is implied as
that can only be determined by the customer.
If further assistance is required in selecting
the proper motor, please contact R/S Electric
Motors Service.
AGENCIES:
U.L. (Underwriters
Laboratory) and CSA (Canadian Standards
Association)
Where applicable, our motors including Inverter
Duty, have UL listing for explosion proof enclosures,
UL recognized construction for non-explosion
proof enclosures, and UL recognition as a motor/protector
combination. Our motors are also CSA certified
for both explosion proof and non-explosion
proof enclosures.
Motors come with either sleeve
bearings, ball bearings, or roller bearings.
Sleeve bearings are more economical and quieter
than ball. Ball bearings carry heavier loads
and can withstand more severe applications.
Roller bearings are used in large motors for
belted loads. Belting data must be provided
on all belted applications. Standard horizontal
motors can be mounted in a vertical shaft down
orientation (brakemotors exempt).
BLUE
MAX¨ AND BLACK MAX¨ INVERTER DUTY
RATED MOTOR
APPLICATION INFORMATION AND RESTRICTIONS:
General Information:
Variable torque ratings are suitable for operation
from 0 to base speed. Variable torque operation
beyond base speed must be reviewed by your
application specialist.
BLUE MAX¨ and BLACK MAX¨ constant torque
motors provide full rated torque within their
listed speed range, without exceeding their
Class F temperature rating on inverter power.
Ratings in this catalog are based on extensive
testing with IGBT inverters, set at a minimum
3 KHz carrier frequency, and are designed for
operation at 150% of rated torque for one minute,
up to the base speed of the motor (overload
capacity declines to 100% as the motor reaches
maximum speed). These motors accommodate
Constant Horsepower (CHP) operation to 1-1/2
to 2 times base speed, subject to the motor's
maximum safe mechanical speed limit.
It is the responsibility of the startup personnel
during commissioning of the VFD/motor combination
to properly tune the drive to the motor for
the specific application. The correct voltage
boost and volts/Hz settings are application
dependent and unique to each motor. Procedures
for these adjustments should be in your VFD
user manual. WARNING: Power factor correction
capacitors should NEVER be installed between
the drive and the motor.
MAXIMUM
SAFE MECHANICAL SPEEDS
|
Direct-Coupled |
Direct-Coupled |
Motor
Frame |
RPM
3600 |
RPM
1800,1200,900 |
56-184 |
7200 |
5400 |
213-256 |
5400 |
4200 |
284-286 |
5400 |
3600 |
324-326 |
4500 |
3600 |
364-365 |
4500 |
2700 |
404-449 |
3600 |
2700 |
Note: TEFC motors are limited
to 4000 rpm.
Operation above 60Hz will
increase motor noise, vibration, and reduce
bearing life. Do NOT exceed 100 degree C
bearing hub temperature.
For belted loads do not exceed
60Hz speed by more than 25%. NEMA TS shafts
are not suitable for belted loads.
GUIDELINES
FOR APPLICATION OF GENERAL PURPOSE THREE PHASE
MOTORS ON VARIABLE FREQUENCY DRIVES:
General purpose
three phase motors, operated on IGBT inverter
at 3KHz carrier frequency, are suitable for
operation on variable frequency drives per
the following table. (X = Suitable)
Enclosure |
Eff. |
Frame |
Variable
Torque |
2:1
Constant Torque |
10:1
Constant
Torque |
Maximum
Cable Length(ft) @3KHz Carrier Frequency
230
Volt |
Maximum
Cable Length(ft) @3KHz Carrier Frequency
460
Volt |
Maximum
Cable Length(ft) @3KHz Carrier Frequency
575
Volt |
Dripproof |
All |
56-326T |
X |
|
|
600 |
125 |
40 |
Dripproof |
All |
364T-500U |
X |
|
|
1000 |
225 |
60 |
TEFC |
Std |
56-326T |
X |
X |
|
600 |
125 |
40 |
TEFC |
Std |
364T-449T |
X |
X |
|
1000 |
225 |
60 |
TEFC |
Series
E |
143T-256T |
X |
X |
X |
600 |
125 |
40 |
TEFC |
Series
E |
284T-326T |
X |
X |
|
600 |
125 |
40 |
TEFC |
Series
E |
364T-445T |
X |
X |
|
1000 |
225 |
60 |
TEFC |
XRI |
143T-145T |
X |
X |
X |
600 |
125 |
40 |
TEFC |
XRI |
182T-256T |
X |
X |
X |
1000 |
225 |
60 |
TEFC |
XRI |
284T-449T* |
X |
X |
|
1000 |
225 |
60 |
*Except
400HP
NOTE: Higher carrier frequency limits allowable
cable length.
ELECTRICAL
TYPE/STARTING METHOD:
Motors are either capacitor
start, split phase, permanent split capacitor,
or three phase. Capacitor start motors have
high starting torque, high breakdown torque,
and relatively low starting current. Split
phase motors have medium starting torque and
medium starting current. Permanent split capacitor
motors have low starting torque and low starting
current. Three phase motors have high starting
torque, extra high breakdown torque, and typically
very low starting current.
Motors are available in dripproof,
totally enclosed, and explosion proof enclosures.
Dripproof motors have open enclosures and are
suitable for indoor use and in relatively clean
atmospheres. Dripproof motors have ventilating
openings constructed so that drops of liquid
or solid particles falling on the machine at
an angle of not greater than 15 degrees from
the vertical cannot enter the machine.
Totally enclosed motors
are suitable for use in humid environments
or dusty, contaminated atmospheres. Totally
enclosed non-ventilated motors are NOT cooled
by external means. Totally enclosed fan cooled
motors are cooled by external means that
are part of the motor but not in the internal
workings of the motor. Totally enclosed air
over motors are totally enclosed non-ventilated
motors that need to be sufficiently cooled
by external means, provided by the customer.
Explosion proof motors are
also totally enclosed fan cooled or non-ventilated,
but designed for applications in hazardous
atmospheres which contain explosive gases or
dusts. Here is a brief description of the hazardous
locations of both gaseous and dusty atmospheres
as classified by the National Fire Protection
Association's National Electrical Code and
printed from the handbook.
-
Class I, Group A - Atmospheres
containing acetylene.
-
Class I, Group B - Atmospheres
containing hydrogen, fuel, and combustible
process gases containing more than 30 percent
hydrogen by volume, or gases or vapors
of equivalent hazards such as butadiene,
ethylene oxide, propylene oxide, and acrolein.
-
Class I, Group C - Atmospheres
containing ethyl ether, ethylene, or gases
or vapors of equivalent hazard.
-
Class I, Group D - Atmospheres
such as acetone, ammonia, benzene, butane,
cyclopropane, ethanol, gasoline, hexane,
methane, natural gas, naphtha, propane,
or gases or vapors of equivalent hazard.
-
Class II, Group E - Atmospheres
containing combustible metal dusts including
aluminum, magnesium, and their commercial
alloys, or other combustible dusts whose
particle size, abrasiveness, and conductivity
present similar hazards in the use of electrical
equipment.
-
Class II, Group F - Atmospheres
containing carbonaceous dusts, including
carbon black, charcoal, coal, or coke dusts
that have more than 8 percent total entrapped
volatiles, or dusts that have been sensitized
by other materials so that they present
an explosion hazard.
-
Class II, Group G - Atmospheres
containing combustible dusts not included
in Group E or F, including flour, grain,
wood, plastic, and chemicals.
Consult the National Electrical
Code for more information on explosion proof
regulations.
Explosion proof motors
are UL listed in Class I, Division 1 Group
D and Class II, Division 1 Groups F and G
ratings; Class I, Division 1 Groups C and
D and Class II, Groups F and G (56/140) ratings;
or Class I, Division 1 Group D only.
FREQUENCY/HERTZ:
The number of complete alternations
per second of an alternating current. Expressed
in Hertz as 60 Hz, 50 Hz, or 60/50 Hz.
GENERAL
PURPOSE, DEFINITE PURPOSE, AND SPECIAL PURPOSE:
There are three groups of
motors as defined by NEMA. They are general
purpose, definite purpose, and special purpose.
General purpose motors can handle a wide variety
of applications. They have NEMA torque, NEMA
limited current, conservative temperatures,
and rugged construction. Special purpose motors
are more economical than general purpose. They
have moderately high torque and are designed
for specific loads. Definite purpose motors
are designed for a specific application. Often
they are restricted in use by their physical
and electrical characteristics. Good examples
would be oil burner motors, condenser fan motors,
and double shaft fan and blower motors.
HORSEPOWER:
Motors are available from
1/12 to 600 horsepower.
MOUNTING:
There are several mounting
configurations available: Rigid base or resilient
base for belted drive applications (the
resilient base also minimizes vibration and
noise), C-Face, D-flange, P-Base, thru-bolt,
resilient ring (only), and belly band
mount are for direct drive applications.
NEMA
DESIGN CODES - THREE PHASE
Design
Letter |
Starting
Torque |
Breakdown
Torque |
Starting
Current |
Slip
at
Rated
Load |
A |
Normal |
High |
High |
Low |
B |
Normal |
Medium |
Normal |
Low |
C |
High |
Normal |
Low |
Low |
D |
Very
High |
N/A |
Low |
High |
NEMA
SERVICE FACTOR RATINGS:
The table below lists the
NEMA service factors for single phase, dripproof
motors. Totally enclosed and explosion proof
motors have 1.0 service factors, except where
noted.
Single
Phase
NEMA SERVICE FACTOR @ RPM
LISTED
HP |
3600 |
1800 |
1200 |
900 |
1/12 |
1.4 |
1.4 |
1.4 |
1.4 |
1/8 |
1.4 |
1.4 |
1.4 |
1.4 |
1/6 |
1.35 |
1.35 |
1.35 |
1.35 |
1/4 |
1.35 |
1.35 |
1.35 |
1.35 |
1/3 |
1.35 |
1.35 |
1.35 |
1.35 |
1/2 |
1.25 |
1.25 |
1.25 |
1.15 |
3/4 |
1.25 |
1.25 |
1.15 |
1.15 |
1 |
1.25 |
1.15 |
1.15 |
1.15 |
1.5 & Up |
1.15 |
1.15 |
1.15 |
1.15 |
OVERLOAD
PROTECTION:
There are four choices in
protection: manual (inherent type),
automatic (inherent type), thermostats,
and none. A manual overload must be physically
reset to restart the motor. An automatic thermal
overload will stop the motor when it is overloaded
or overheated and restart it after the motor
has cooled down. None means the motor has no
protection. Thermostats are embedded in the
winding and connected to the motor starter
control circuit.
CAUTION
NOTE!
A MOTOR WITH AN AUTOMATIC RESET PROTECTOR
MUST NOT BE USED WHERE AUTOMATIC RESTARTING (AFTER
MOTOR COOL-DOWN) WOULD ENDANGER PERSONNEL
OR EQUIPMENT. SUCH APPLICATIONS SHOULD
USE A MANUAL RESET PROTECTOR. |
PHASE/POWER
SUPPLY:
Is the power supply three
phase or single phase? Most home and farm applications
require single phase motors, while most factories
and large commercial and industrial users require
three phase motors. Single phase motors can
be used on three phase systems. Three phase
motors, however, cannot be operated from single
phase systems. Motor damage may result.
ROTATION:
Most motors on this website
are reversible by electrical reconnection or
by physical orientation.
SERVICE
FACTORS:
Motors are available in either
NEMA or 1.0 service factors. A 1.0 service
factor motor will perform to its nameplate
rating. A NEMA service factor motor can exceed
its horsepower rating periodically. (See
table under NEMA Service Factor Ratings.)
SPEED/RPM:
3600, 1800, and 1200 are
the most common 60 Hz synchronous speeds with
the full load speed equivalents of 3450, 1725,
and 1150.
VOLTAGE:
Standard voltages are 115V,
115/230V, 230V, 230/460V, 460V, and 575V at
60 Hertz. Many of our ratings are 115/208-230V
or 208-230/460V at 60 Hertz. Dual voltage motors
are easily reconnected from information shown
on the nameplate of the motor. Motors rated
at 230 volts will operate on a 208 volt network
for most applications that have nominal starting
torque requirements. Starting torque and peak
running torque at 208 volts will be 20-25%
less than at the 230 volt level. If the starting
torque is more than nominal, the next higher
horsepower 230 volt motor should be used. Motors
nameplated 115/208-230 or 208-230/460 volts
will operate successfully at 208 volts. At
208 volts, the motors may not meet NEMA specifications.
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