Guardian Technologies 004270-3 Additional Information, Overspeed Shutdown, Overvoltage Protection

Section 2 – Operation

QUIETPACT™ 75D Recreational Vehicle Generator

Figure 2.2 – Engine Protective Devices	The voltage regulator also incorporates a “voltage
	surge protection circuit.” This circuit prevents trou-
	blesome surges in the generator AC output voltage.
	Voltage surge is a common cause of damage to elec-
	tronic equipment.

◆2.7.3 OVERSPEED SHUTDOWN

A DC control circuit board senses engine speed from the frequency of the alternator AC output. Should the alternator output frequency exceed approximately 72 Hertz (4,320 alternator rpm), circuit board action initiates an automatic engine shutdown.

◆2.7.4 OVERVOLTAGE PROTECTION

A solid-state voltage regulator (Figure 2.3) controls the generator’s AC output voltage. This regulator sup- plies an excitation current to the rotor. By regulating the rotor’s excitation current, the strength of its mag- netic field is regulated and, in turn, the voltage deliv- ered to connected electrical loads is controlled. When the AC frequency is 60 Hertz, voltage is regulated at 120 volts (voltage-to-frequency ratio is 2-to-1).

Figure 2.3 – Solid-state Voltage Regulator

2.8ADDITIONAL INFORMATION

◆2.8.1 25-HOUR BREAK-IN PERIOD

The first 25 hours of operation is the break-in period for the generator. Properly breaking in the generator is essential to minimize oil consumption and maxi- mize engine performance. During this 25-hour break-in period, observe the following rules:

•Run the unit at varying electrical loads to help seat the engine piston rings properly.

•After operating the unit for 25 hours, complete the tasks recommended under Section 2.8.2.

•For the next 75 hours of operation, following the break-in period, avoid light electrical loads. Load the generator at 50 percent (or more) of its rated wattage capacity. Repeated light loads during these 75 hours can cause improper seating of engine pis- ton rings, resulting in blowby and high oil con- sumption.

•Check the engine oil level frequently. Add oil if needed. It is normal for the generator engine to consume more oil than normally, until the piston rings have properly seated.

◆2.8.2 25-HOUR CHECK-UP

After the 25-hour break-in period, contact a Generac Authorized Service Dealer for the following mainte- nance, for which the vehicle owner is responsible for all charges:

•Change the engine crankcase oil and oil filter.

•Check all fluid levels (engine coolant, fuel, battery electrolyte fluid).

•Visually inspect the unit for any leaks or loose hardware.

•Inspect the exhaust tailpipe for any leaks or damage.

◆2.8.3 ATTENTION REQUIRED

AFTER SUBMERSION

If the recreational vehicle generator has been sub- merged in water, it MUST NOT be started and oper- ated. Following any submersion in water, have a Generac Authorized Service Dealer thoroughly clean and dry the generator.

10 Generac® Power Systems, Inc.