5. motor slection guide.ppt

7/28/2019 5. Motor Slection Guide.ppt

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Applied Electricity EE 2850


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Factors to Consider inSelecting Electric Motors


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DC motors

3 - phase Induction Motors

Universal motors

Stepper motors

1 phase induction motors

Brushless DC motors

..

..

Depending on the application, different combinations ofparameters should be considered.


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Factors to be considered Power source

AC (120 V, 220 V, )

DC (batteries, etc) Single-phase or three-phase

Torque requirement (or power)

hp rating

Constant torque / Variable torque

Starting torque


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RPM requirements

A gear reduction is incorporated after the motor output

or Motor need to supply a certain RPM

Gear reduction:provides speed and torque conversions from arotating power source to another device using gearratios


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Positioning during rotation Precision stopping

Breaking

Reversing (AC motors are easily reversed)

Note: For precision stopping control-Stepper Motors-Servo Motors

Servo motors:sense position of the motor and control accordingly

Stepper motors:move to specified angles (no way to sense)


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Speed control requirementsNote:

If speed control is needed DC are much easier

(AC motors require frequency control instead of voltagecontrol)

Mounting position

What mounting options are there?

Continuous / intermittent operation Will the motor operates for long periods of time?


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Operating environment What atmosphere will the motor be operating in? Will there be sensitive materials nearby?

Physical size Length Diameter

Insulation type

Cooling method

Cost


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Nameplate information


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THERMALLY PROTECTED:

Equipped with devices designed to disconnect thecurrent flow if insulating materials become too hot

SER 12P 14666J: Manufacturers serial number

MOD HE3E207N: Manufacturers model number

STK NO.619: Manufacturers stock number

VOLTS 208-230: Motor can operate on either 208V or 230V

HZ 60: Frequency which the motor is designed tooperate


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AMPS 1.2: Motor draws 1.2A when operating at full

load

RPM 1075: Motor turns 1075 revolutions per minutewhen pulling its rated load

PH1: Motor runs on single phase power

CAPS 5MFD 370VAC: Equipped with a run capacitor, rated at 5

micro farads and 370V AC

INS CL B: Has Class B insulation, providing protectionup to 1300 C


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AMB 600 C: Rated to work at an ambient temperature of 600 C

HP 1.5: Designed to pull a 1/5 hp load when operated atrated voltage

CONT: Continuous duty

(Motor will pull rated load under rated conditionscontinuously and not over heat. Motor may haveintermittent duty)

AO: Air-over ventilation is used for cooling

ROT REV: Direction of rotation

BRG SLV: Motor has sleeve bearings


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Motor Protection andMaintenance


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Visually inspect for anything harmful

Listen for strange noises, humming or tapping

Smell to check for burning

Feel motor housing to be sure it has not overheated

Visually check to make sure motor is not vibratingexcessively

Check the condition of bearings, belts, pulleys,..


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Protect from excessive oiling

Excessive oil causes accumulation of extra dust ordeterioration of insulation

Protect from dust

Cause excessive heating Wipe motor off at regular intervals

See that oil filter caps are closed

See that dust seals are in good condition

Protect from moisture Moisture is a conductor of electricity

A wet motor should be dried before used

5. motor slection guide.ppt

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