SECTION 16040 - ELECTRIC MOTORS
City of San Diego, CWP Guidelines
PART 1 -- GENERAL
1.1 WORK OF THIS SECTION
A. The WORK of this Section includes providing electric motors with accessories.
1.2 RELATED SECTIONS
A. The WORK of the following Section applies to the WORK of this Section. Other Sections
of the specifications, not referenced below, shall also apply to the extent required for proper
performance of this WORK.
1. Section 16050 Basic Electrical Materials and Methods
1.3 CODES
A. The WORK of this Section shall comply with the current editions, with revisions, of the
following codes and City of San Diego Supplements:
1. National Electrical Code
1.4 SPECIFICATIONS AND STANDARDS
A. Except as otherwise indicated, the current editions of the following apply to the WORK of
this Section:
1. AFBMA 9 Load Ratings and Fatigue Life for Ball Bearings.
2. AFBMA 11 Load Ratings and Fatigue Life for Roller Bearings.
3. ANSI/IEEE 112 Standard Test Procedure for Polyphase Induction Motors
and Generators.
4. IEEE 841 Standard for Petroleum and Chemical Industry—Totally
Enclosed Fan-Cooled (TEFC) Squirrel Cage Induction
Motors—Up to and Including 500 HP
5. NEMA ICS 2 Industrial Control Devices, Controllers and Assemblies.
6. NEMA ICS 6 Enclosures for Industrial Controls and Systems.
7. NEMA MG 1 Motors and Generators.
8. UL 674 Motors and Generators, Electric, for Use in Hazardous
Locations, Class I, Groups C and D, Class II, Groups E, F
and G.
9. UL 1004 Motors, Electric
SHOP DRAWINGS AND SAMPLES
[NOVEMBER 1999] ELECTRIC MOTORS
[CONTRACT NO.]-[CONTRACT NAME] 16040-1
B. The following shall be submitted in compliance with Section 01300:
1. Machine name and submitted data on driven machine.
2. Motor manufacturer.
3. Motor type, model and dimensioned drawing.
4. Nominal horsepower.
5. NEMA design.
6. Frame size.
7. Enclosure.
8. Winding insulation class and treatment.
9. Rated ambient temperature.
10. Service factor.
11. Voltage, phase, and frequency rating.
12. Full load current at rated horsepower and indicated voltage.
13. Starting code letter, or locked rotor kVA, and current.
14. Special winding configuration.
15. Rated full load speed.
16. Power Factor at full load.
17. Details of water cooling (if any) for thrust bearings.
18. Motor efficiencies.
PART 2 -- PRODUCTS
2.1 GENERAL REQUIREMENTS
A. Conformance: Electric motors driving identical machines shall be identical.
B. Rating: The nominal rated motor horsepower shall be adequate for the driven machine
without infringing upon the indicated motor service factor, unless more restrictive motor
requirements are specified for a specific equipment item.
C. Minimum Motor hp: The motor horsepower shall be not less than the minimum indicated
for each driven machine. If the minimum horsepower is not adequate, the motor with the
next larger horsepower, circuit breakers, magnetic starters, motor feeder conductors and
conduit shall be provided.
D. Exempt Motors: Except as otherwise indicated, motors intended for valve operators,
submersible pumps and hoists, motors which are an integral part of standard manufactured
equipment, i.e., non-NEMA mounting, common shaft with driven equipment, part of
commercial use or domestic equipment and torque-rated motors shall be motors
recommended by the manufacturer for use in the application indicated.
2.2 DESIGN REQUIREMENTS
A. General: Electric motors shall comply with ANSI/NEMA MG 1.
B. NEMA Design: Except as otherwise indicated, electric motors shall be NEMA Design B,
constant speed squirrel-cage induction motors designed for normal starting torque with low
starting current. In no case shall starting torque or breakdown torque be less than the
value indicated in ANSI/NEMA MG 1. Motors shall be suitable for part-winding, star delta
starting, or 2 speed winding, where indicated.
C. Motor Voltage Ratings: Motors shall be rated in accordance with the following:
[NOVEMBER 1999] ELECTRIC MOTORS
[CONTRACT NO.]-[CONTRACT NAME] 16040-2
1. Motors below 1/2-hp shall be rated 115 volts, single-phase, 60-Hz. Dual voltage
motors rated 115/230-volts, 115/208-volts, or 120-240 volts are acceptable.
2. Motors 1/2-hp and larger shall be rated 460 volts, or 4160 volts, 3-phase, 60-Hz. Dual
voltage motors rated 230/460 volts or 208/230/460 volts are acceptable.
D. Explosion-Proof Motors: Motors which will be installed in Class I or Class II areas
(exposed to flammable vapors, gases, or dust) shall be explosion-proof and shall bear
Underwriter's approval on name plate and serial number.
E. Insulation (Standard Duty Motors): Standard duty motors shall include Class F
insulation, rated to operate at an ambient temperature of 40 degrees C without exceeding
Class B temperature rise limits at the motor’s nominal rating.
F. Insulation (Heavy Duty Motors): Heavy duty motors shall include Class F insulation,
rated to operate at an ambient temperature of 50 degrees C without exceeding Class B
temperature rise limits at the motor’s nominal rating
G. Motors Installed Outdoors: Motors 50 Hp or smaller which will be installed outdoors shall
be totally enclosed, fan cooled (TEFC) with a Service Factor of 1.15.
H. Motors larger than 50 hp: Motors larger than 50 hp which will be installed outdoors shall
be Weather-Protected Type II. Motors larger than 50 hp shall have a minimum service
factor of 1.15 and 2 cycles of solid, baked epoxy vacuum impregnation and shall include
rodent screens.
I. Motors Installed Indoors: Except as otherwise indicated, all motors which will be installed
indoors shall be open drip-proof with a service factor of 1.15 minimum except that motors
larger than 50 hp, located in damp environment (pump and pipe galleries, tunnels, chemical
feed and sludge areas) shall have 2 cycles of solid baked epoxy vacuum impregnation.
J. High Efficiency Motors: Motors with a nameplate rating of 5 hp and above shall be "high
efficiency" units with efficiencies determined by the test set forth in ANSI/IEEE 112, Method
B with stray load loss adjustment as modified by NEMA MG 1-12.53(a) and (b).
K. Efficiency Index: Efficiency index, nominal efficiency, and minimum efficiency shall be
defined in accordance with ANSI/NEMA MG 1-12.53.b. Motor nameplate data shall include
the nominal efficiency value.
L. Minimum Motor Full Load Power Factor: [0.85] [0.92]
M. High efficiency Motors: High efficiency motors shall conform to the following minimum
efficiency requirements for full load values:
Guaranteed Minimum Efficiency
Motor Synchronous (percent)
hp Speed, rpm Open Enclosed
5 3600 86 86
1800 87 87
1200 88 88
7-1/2 3600 86 86
[NOVEMBER 2000] ELECTRIC MOTORS
[CONTRACT NO.]-[CONTRACT NAME] 16040-3
1800 89 89
1200 88 88
10 3600 89 89
1800 89 89
1200 89 89
15 3600 89 89
1800 90 90
1200 90 90
20 3600 90 90
1800 91 91
1200 90 90
25 3600 90 90
1800 92 92
1200 90 90
30 3600 91 91
1800 92 92
1200 90 90
40 3600 92 92
1800 92 92
1200 92 92
50 3600 91 91
1800 92 92
1200 92 92
75 3600 93 93
1800 94 94
1200 92 92
100 3600 93 93
1800 94 94
1200 93 93
125 3600 94 93
1800 94 94
1200 94 94
150 3600 93 93
1800 95 95
1200 94 94
200 3600 94 94
1800 95 95
1200 94 94
300 3600 95 95
1800 95 95
[FEBRUARY 1991] ELECTRIC MOTORS
[CONTRACT NO.]-[CONTRACT NAME] 16040-4
N. Motors for VFD Drives: Motors for variable frequency drives (VFD) shall be specifically
rated for inverter duty and shall be severe duty NEMA MG 1 design A or B, high efficiency,
totally enclosed fan cooled (TEFC) with NEMA MG 1 Class F insulation. Winding
temperature rise shall be limited to Class B rise when operating over the speed range
specified in VFD Section 11033 with the specified load speed/torque characteristic. Six
100-ohm platinum resistance temperature detectors (RTDs) shall be provided in the stator
windings for motors 100 Hp and larger. Motor insulation shall be designed to meet NEMA
MG 1, Part 31 (1600-volt peak at a minimum of 0.1 microsecond rise time). Motors shall
conform to IEEE 841. All internal surfaces shall be coated with epoxy paint.
Inverter duty motors shall be specifically certified by the motor manufacturer to be
compatible with the VFD to be used with the motor. Inverter duty motors shall be designed
to operate over the speed or frequency range specified. Inverter duty motors shall be
provided with Type 2 thermal protection as specified in NEMA MG 1-12.53.2.
Inverter duty motors shall be equipped with a shaft-grounding unit mounted on the fan
housing with stub shaft extended from the motor shaft. Grounding unit shall be equipped
with two brushes, totally enclosed and sealed against environmental contamination.
Where specified, or required by the specified application requirements, inverter duty motors
shall be totally enclosed, air-over blower-cooled (TEBC). Blowers shall be driven at
constant speed by 460-volt, 3-phase, 60 Hz motors. Blower motor shall be TEFC in
conformance with paragraph 16040-2.2 G. Blower and ducting shall be an integral part of
the main motor frame. Air intake filter shall be provided. Scroll case shall be cast
aluminum or iron, and fan wheel shall be Type 304 stainless steel.
O. Stator Windings and Resistance Temperature Detectors: Stator windings shall be
copper. Except as otherwise indicated, six 100-ohm platinum resistance temperature
detectors (RTDs) shall be provided in the stator windings for motors greater than 250 Hp;
and one PTC thermister shall be provided on the stator windings for motors from [50] [60]
to 250 Hp.
P. Space Heaters: 120 volt space heaters shall be provided on all [15] Hp and larger motors
[that may not operate continuously].
2.3 MOTOR BEARINGS
A. General: Bearings shall comply with Section 11000.
B. Standard Duty: Except as otherwise indicated, motors shall be standard duty and shall
include bearings with a minimum L-10 life of 50,000 hours.
C. Heavy Duty: Where equipment for heavy duty service is indicated, motors shall be heavy
duty and shall include bearings designed for a minimum rated L-10 life of 100,000 hours.
D. Fractional Horsepower: Fractional horsepower through 2 hp motors shall be furnished
with self lubricated ball bearings.
E. Horizontal Motors Over 2 hp: Motors larger than 2 hp shall include relubricatable ball
bearings except where vertical pump motors are indicated.
F. Vertical Motors Over 2 hp: Vertical motors larger than 2 hp shall be furnished with
relubricatable ball, spherical, roller, or plate type thrust bearings. Lubrication shall comply
with the manufacturer's recommendations.
[NOVEMBER 1999] ELECTRIC MOTORS
[CONTRACT NO.]-[CONTRACT NAME] 16040-5
G. Water-Cooled Motors: If water cooling is required for the thrust bearings, cooling water
lines shall be provided with shut-off valve, strainer, solenoid valve, flow indicator,
thermometer and throttling valve.
H. Temperature Detectors: Except as otherwise indicated, one RTD per sleeve bearing (or
vibration switch for ball bearings) shall be provided for motors greater than 250 Hp.
2.4 ACCESSORY REQUIREMENTS
A. General: Horizontal motors 3 hp and larger, and all vertical motors, shall have split-type
cast metal conduit boxes. Motors other than open drip-proof shall include gaskets.
B. Lifting Devices: All motors weighing [50] [265] lb or more shall include lifting devices
designed for installation and removal.
C. Terminal Boxes: Motors rated at 4160-volts shall have extra large terminal boxes to
accommodate stress cone terminations as recommended by cable manufacturers.
D. Space Heaters: Except as otherwise indicated, all motors 25 hp and larger shall be
furnished with space heaters. Space heater rating shall be 120 volts, single-phase, unless
otherwise indicated.
E. Nameplate: Motors shall include a permanent, non-corrosive nameplate indelibly stamped
or engraved with NEMA Standard motor data, including bearing description and lubrication
instructions, insulation class, ambient temperature, and power factor at full load.
2.5 MANUFACTURER
A. Motors shall be manufactured by the following (or equal). :
General Electric Company
Louis Allis (Division of Magnatek, Inc.)
U.S. Motors Corporation
Westinghouse Electric Corporation
B. Inverter duty motors shall be manufactured by the following (or equal):
Baldor, Inverter Motor
Reliance, RPM-XT
U.S. Motors, Inverter Grade
PART 3 -- EXECUTION
3.1 INSTALLATION
A. Motors shall be installed in accordance with the manufacturer's installation instructions and
written requirements of the manufacturer of the driven equipment.
** END OF SECTION **
[NOVEMBER 1999] ELECTRIC MOTORS
[CONTRACT NO.]-[CONTRACT NAME] 16040-6
