Kohler 10EOR, Service

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TP-6073 4/06 42 Section 7 Generator Troubleshooting
7.5 PowerBoost
t
V Voltage
Regulators (15 and 20 kW
Models)
The generator set is equipped with a PowerBoost
t
V
voltage regulator. See Figure 7-6. The PowerBoost
t
V
voltage regulator monitors output voltage magnitude to
control the current to the generator exciter field. The
voltage regulator has an underfrequency unloading
feature that is referred to as volts-per-Hz (V/Hz). To
determine if the voltage regulator is functioning, reduce
the engine speed (Hz) and watch for a corresponding
drop in the AC voltage. The AC voltage should remain
constant until the engine speed drops below 57.5 Hz on
60 Hz models or 47.5 Hz on 50 Hz models.
When the frequency drops below either 57.5 or 47.5 Hz,
the AC voltage should decline. Perform the following
test to check the regulator output.
TP-593657
8
7
6
5
4
3
2
1
Input
Green
Output
Red
STAB
Sensing
Yellow
V/HZ VOLTS
1
2
3
4
5
6
1. LED1 (green input)
2. LED2 (red output)
3. Voltage potentiometer 4. LED3 (yellow sensing)
5. Volts/Hz potentiometer
6. Stability potentiometer
Figure 7-6 PowerBoost
t
V Voltage Regulator
7.5.1 PowerBoost
t
V Voltage
Regulator Test
Use the following components to test the voltage
regulator:
D
Step-up transformer, 1:2, 120 volts to 240 volts
(1.0-amp minimum)
D
Lamp, 250-volt, 100-watt
D
AC voltmeter (250-volt minimum)
D
Fuse,1-amp
D
Switch,1 single-pole single-throw (SPST) (1-amp
minimum)
D
Plug, 120-volt AC (200--240 volt AC plug optional)
D
Insulated copper wire, #14 AWG (minimum)
PowerBoost
t
V Voltage Regulator Test
Procedure:
1. Connect the components as shown in Figure 7-7.
If a 200--240 volt power source is available, the
step-up transformer is not required.
2. Turn the volts potentiometer fully counterclockwise.
3. Plug the power cord into the outlet.
4. Turn the power supply on. The AC voltmeter
should indicate a power supply voltage of
200--240 volts. The lamp should be off. If the lamp
is lit, replace the voltage regulator.
5. Slowly turn the volts adjustment potentiometer
clockwise. The lamp should light. Replace the
voltage regulator if the lamp does not light.
66
55
8
7
6
5
4
3
2
1
Input
Green
Output
Red
STAB
Sensing
Yellow
V/HZ VOLTS
1
2
3
4
5
6
7
8
9
10
11
12
13
14
7
8
11
13 TP-593655
1. LED1 (input)
2. PowerBoost
t
V voltage regulator
3. LED2 (output)
4. 250-volt, 100-watt lamp
5. AC voltmeter 250 volt (minimum)
6. 1:2 step-up transformer
7. Single-pole single-throw switch
8. 1-amp fuse
9. LED3 (sensing)
10. Volts potentiometer
11. Black wire
12. 100--120 VAC
13. White wire
14. 200--240 VAC (optional)
Figure 7-7 PowerBoost
t
V Voltage Regulator Test