Generac 004373-3, 004626-2 Main Circuit Breaker, Engine Protective Devices, Specifications

Section 1 — General Information

Guardian Liquid-cooled 40 kW Generator

1.6MAIN CIRCUIT BREAKER

The generator’s main circuit breaker is included with the unit as shipped from the factory. The breaker for each unit is described as follows:

Model Number	Circuit Breaker Rating
004373-3	200-amp breaker
004626-2	200-amp breaker

‹1.7.3 LOW COOLANT LEVEL SWITCH

Should the engine coolant level drop below the level of the high coolant temperature switch, it is possible for the engine to overheat without automatic shut down. To pre- vent such overheating without automatic shut down, the engine has a low coolant level sensor. If the engine coolant drops too low, the engine automatically shuts down (Figure 1.2).

1.7ENGINE PROTECTIVE DEVICES

The engine has several safety switches that cause it to automatically shut down under the following condi- tions: low oil pressure, high coolant temperature, low coolant level, engine overspeed and overcrank.

‹1.7.4 OVERSPEED SHUTDOWN

The control module assembly (CMA) circuit board on liquid-cooled units receives AC frequency (rpm) signals directly from the stator AC power windings. Should AC frequency exceed approximately 72 Hertz, circuit board action will automatically shut down the engine.

‹1.7.1 LOW OIL PRESSURE SWITCH

This switch is normally closed (N.C.) but is held open by engine oil pressure during engine running. Should oper- ating oil pressure drop below approximately 10 psi (68 kPa), the switch contacts close, and the engine shuts down automatically (Figure 1.2).

Figure 1.2 – Engine Protective Devices

‹1.7.2 HIGH COOLANT TEMPERATURE SWITCH

This normally open (N.O.) thermostatic switch has a sensing tip that is immersed in captive coolant. Should the coolant temperature exceed approximately 121° C (250° F), the switch contacts close, which causes the engine to shut down automatically (Figure 1.2).

‹1.7.5 OVERCRANK SHUTDOWN

After 90 seconds of crank-rest cycles (about seven sec- onds cranking/seven seconds at rest), this function ends cranking if the engine fails to start in that 90-second span.

‹1.7.6 DC FUSE

This fuse is located on the front panel of the control sys- tem. It protects the panel wiring and components from damaging overload. Always remove this fuse before commencing work on the generator. The unit will not start or crank if the fuse is blown. Replace the fuse with one of the same size, type, and rating. Generac uses an AGC fuse rated at 15 amps.

1.8SPECIFICATIONS

◆ 1.8.1 GENERATOR
Models	004373-3 & 004626-2
Rated Maximum Continuous
AC Power Output (kW)*		40
Rated Voltage (volts)		120/240
Rated Maximum Continuous
Current at 240 Volts, Single-phase (amps)		167
Number of Rotor Poles		4
Driven Speed of Rotor (rpm)		1,800
Type of Stator		Four-wire
Rotor Excitation System		Direct Excited
		Brush-type System
Stator Insulation		Class “H”
Rotor Insulation		Class “F”

*Rated power of generator is subject to and limited by such factors as ambient tempera- ture, altitude, engine condition and other factors. Engine power will decrease about 3.5 percent for each 1,000 feet above sea level; and also will decrease an additional 1 percent for each 6° C (10° F) above 15.5° C (60° F) ambient. Maximum output power of the gener- ator is limited by maximum engine power.

Generac® Power Systems, Inc. 5