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Guardian Technologies 4270 User Manual

Page 52

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Section 7
DIAGNOSTIC TESTS

Figure 7-16. – Clamp-On Ammeter

TACHOMETER:
A tachometer is available from your Generac Power
Systems source of supply. Order as P/N 042223. The
tachometer measures from 800 to 50,000 RPM (see
Figure 7-17).

Figure 7-17. – Tachometer

Figure 7-18. – Test Bracket

TEST BRACKET:
A starter motor test bracket may be made as shown
in Figure 7-18.

REMOVE STARTER MOTOR:
It is recommended that the Starter Motor be removed
from the engine when testing Starter Motor perfor-
mance. Assemble starter to test bracket and clamp
test bracket in vise (Figure 7-19).

TESTING STARTER MOTOR:

1. A fully charged 12 VDC battery is required.

2. Connect jumper cables and clamp-on ammeter as shown in

Figure 7-19.

3. With the Starter Motor activated (jump the terminal on the

Starter Contactor to battery voltage), note the reading on the
clamp-on ammeter and on the tachometer (rpm).

N o t e : T a k e t h e r e a d i n g a f t e r t h e a m m e t e r
and tachometer are stabilized, approximately
2-4 seconds.

4. A starter motor in good condition will be within the following

specifications:

Minimum rpm

4500

Maximum Amps

50

Note: Nominal amp draw of starter in generator is
60 amps.

Figure 7-19. – Testing Starter Motor Performance

STARTER

CONTACTOR

STARTER

MOTOR

TACHOMETER

12 VOLT

BATTERY

CLAMP ON

AMP METER

VISE

15"

3.5"

3.5"

3"

1.5"

2"

4"

2"

1.75

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