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Generac Power Systems Recreational Vehicle Generator 5413 User Manual

Page 18

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Section 4
MEASURING ELECTRICITY

Correct engine and Rotor speed is maintained by a

stepper motor governor. For models rated 60 Hertz,

the governor is generally set to maintain a no-load fre-

quency of about 60 Hertz with a corresponding output

voltage of about 124 volts AC line-to-neutral.

MEASURINg CURRENT

To read the current flow, in AMPERES, a clamp-on

ammeter may be used. This type of meter indicates

current flow through a conductor by measuring the

strength of the magnetic field around that conductor.

The meter consists essentially of a current trans-

former with a split core and a rectifier type instrument

connected to the secondary. The primary of the cur-

rent transformer is the conductor through which the

current to be measured flows. The split core allows

the Instrument to be clamped around the conductor

without disconnecting it.
Current flowing through a conductor may be mea-

sured safely and easily. A line-splitter can be used

to measure current in a cord without separating the

conductors.

Figure 4-2. – Clamp-On Ammeter

Figure 4-3. – A Line-Splitter

NOTE: If the physical size of the conductor or

ammeter capacity does not permit all lines to be

measured simultaneously, measure current flow

in each individual line. Then, add the Individual

readings.

MEASURINg RESISTANCE

The volt-ohm-milliammeter may be used to measure

the resistance in a circuit. Resistance values can be

very valuable when testing coils or windings, such as

the Stator and Rotor windings.
When testing Stator windings, keep in mind that the

resistance of these windings is very low. Some meters

are not capable of reading such a low resistance and

will simply read “continuity”.
If proper procedures are used, the following condi-

tions can be detected using a VOM:

A “short-to-ground” condition in any Stator or Rotor

winding.

Shorting together of any two parallel Stator wind-

ings.

Shorting together of any two isolated Stator wind-

ings.

An open condition in any Stator or Rotor winding.

Component testing may require a specific resistance

value or a test for “infinity” or “continuity.” Infinity is an

OPEN condition between two electrical points, which

would read as no resistance on a VOM. Continuity is a

closed condition between two electrical points, which

would be indicated as very low resistance or “ZERO”

on a VOM.

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