Preparing the unit, Starting electric motors, Unpacking – Winco EC22000/A User Manual

Page 5

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STARTING ELECTRIC MOTORS

Electric motors require much more current (amps) to

start them than to run them. Some motors, par-

ticularly low cost split-phase motors, are very hard

to start and require 5 to 7 times as much current

to start them as to run them. Capacitor motors are

easier to start and usually require 2 to 4 times as

much current to start them as to run them. Repul-

sion Induction motors are the easiest to start and

require  /2 to 2 /2 times as much to start them as

to run them.

Most fractional horsepower motors take about the

same amount of current to run them whether they

are Repulsion Induction (RI), Capacitor (Cap), or

Split-Phase (SP) type. The chart below shows the

approximate current required to start and run various

types and sizes of 20 volt 60 cycle electric motors

under average load conditions.

HP

AMPS

RUNNING

STARTING AMPS

SP

CAP

RI

1/6

3.2

16 to 22

6 to 13

5 to 8

1/4

4.5

22 to 32

9 to 18

7 to 12

1/3

5.2

26 to 35

10 to 21

8 to 17

1/2

7.2

not made 14 to 29 11 to 18

1

13.0

not made 26 to 52 20 to 33

The figures given above are an average load such

as a blower or fan. If the electric motor is connected

to a hard starting load such as an air compressor, it

will require more starting current. If it is connected

to a light load, or no load such as a power saw, it will

require less starting current. The exact requirement

will also vary with the brand or design of the motor.

Self-exciting generators respond to severe overload-

ing differently than utility power. When overloaded,

the engine is not able to supply enough power to

bring the electric motor up to operating speed. The

generator responds with high initial starting current,

but the engine speed drops sharply. The overload

may stall the engine. If allowed to operate at very

low speeds, the electric motor starting winding will

burn out in a short time. The generator winding

might also be damaged.

CAUTION: EQUIPMENT DAMAGE

RUNNING THE GENERATOR SET UNDER THESE

CONDITIONS MAY RESULT IN DAMAGING THE

GENERATOR STATOR AS WELL AS THE MOTOR

WINDING.

The heavy surge of current required for starting

motors is required for only an instant. The genera-

tor will not be damaged if it can bring the motor up

to speed in a few seconds of time. If difficulty is

experienced in starting motors, turn all other electri-

cal loads off and if possible reduce the load on the

electric motor.

PREPARING THE UNIT

UNPACKING

CAUTION: EQUIPMENT DAMAGE

THIS UNIT HAS BEEN SHIPPED

WITHOUT OIL.

Failure to maintain the engine oil at the proper level

will result in serious engine damage.

When you unpack your new engine-generator set be

sure to remove all the information sheets and manu-

als from the carton.

. This generator-set was in good order when

shipped. Inspect the generator-set promptly after

receiving it. If any damage is noted, notify the trans-

portation company immediately; request proper pro-

cedures for filing a “concealed damage” claim. Title

to the equipment and responsibility for filing a claim

rests with you when a generator-set is sent F.O.B.

shipping point. Only you can legally file a claim.

2. Before proceeding with the preparations of your

new generator-set for operation, take a couple of

minutes to ensure the unit you have received is the

correct model and review the specification pages in

this manual to ensure that this unit meets your job

requirements.

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