Kohler 24VDC, 6VSG, 36VDC, 48VDC Generator Set Operation, Theory of Operation, Prestart Checklist

Section 2 Generator Set Operation

2.1 Theory of Operation

The generator set utilizes a permanent-magnet alternator to produce 3-phase AC voltage. This voltage is rectified using a full-wave 3-phase rectifier (single block rectifier for 36V and 48V, three individual rectifier blocks for 24V) to produce low-ripple DC output. See Figure 2-1and Figure 2-2.

The VSC measures the average DC voltage on the output and lists this on the auto-scrolling display, in the Overview menu and in the Generator metering menu.

KPS_105

Figure 2-1Basic VSG Power Connections

KPS_106

Figure 2-2Output Waveform, with Rectified Signal

The voltage is regulated to maintain a constant output voltage, which is equal to the System Voltage setting. When the load on the 6VSG generator increases, the generator controller increases the engine speed. The 6VSG series is designed to produce rated voltage at 2300 rpm with no load and at 2900 rpm when supplying full load. The output current and power increase with the engine speed. The engine speed is

limited to a maximum of 2900 rpm. See Section 3.14.1 for more information.

2.2 Prestart Checklist

To ensure continued satisfactory operation, perform the following checks or inspections before or at each startup, as designated, and at the intervals specified in the service schedule. In addition, some checks require verification after the unit starts.

Air Cleaner. Check for a clean and installed air cleaner element to prevent unfiltered air from entering the engine.

Air Inlets. Check for clean and unobstructed air inlets.

Battery. Check for tight battery connections. Consult the battery manufacturer’s instructions regarding battery care and maintenance.

Enclosure. Check that all enclosure panels and internal baffling are in place.

TP-6843 1/13 Section 2 Generator Set Operation 17