Kohler 4EFOZ/5EOZ, 8.5EFOZ Appendix C Generator Set Output Ratings Procedure, Generator Output

Appendix C Generator Set Output Ratings Procedure

Kohler Co. develops the kilowatt output rating of a Kohlerr marine generator set based upon the calculations specified in ISO 3046 and ISO 8528-1. The calculations correct for environmental variables encountered in a

generator set installation. Figure 1 outlines the calculations. Figure 2 contains examples of how heat variables affect generator set ratings.

Generator Output corrected = Generator Output observed x Correction Factor

Output power is expected to be within ±5% of the specified rating when corrected to reference conditions. Correction factors are determined using the following formulas:

1.For naturally aspirated compression-ignition engines (power limited by excess air): C.F. = [1.175 (29.2 / Dry Barometer in. Hg)1 (Temperature _F + 460/537).75 -- .175]

xAlternator Efficiency Reference / Alternator Efficiency Observed

2.For turbocharged compression ignition engines:

C.F. = [1.175 (29.2 / Barometer Observed in. Hg).7 (Temperature _F + 460/537)2 -- .175]

xAlternator Efficiency Reference / Alternator Efficiency Observed

3.For turbocharged and intercooled compression ignition engines:

C.F. = [1.175 (29.2 / Barometer Observed in. Hg).7 (Temperature _F + 460/537)1.2 -- .175]

xAlternator Efficiency Reference / Alternator Efficiency Observed

Reference conditions:

Temperature: 77_F; Pressure: 29.2 in. Hg dry barometer.

Kohler sound shield increases ambient intake air approx. 12_F

Approximate derates:

Temperature: approximately 1% per 10_F (turbocharged engines have a greater derate);

Pressure (altitude): approximately 4% per 1000 ft. (1 in. Hg)

Figure 1 Generator Output

KEY
60 Hz	8.0
50 Hz	7.9
	7.8
	7.7
	7.6
	7.5
	7.4
	7.3
	7.2
	7.1
	7.0
	6.9
	6.8
	6.7
	6.6
	6.5
	6.4
	6.3
	6.2
	6.1
	6.0
	5.9
	5.8
	5.7
	5.6
	5.5
	77	80	85	90	95	100	105	110	115	120
					Temperature (_F)
Figure 2 Example: 6.5EFOZ/8EOZ kW Derates (ISO 3046/ISO 8258-1)

A-4 Appendix TP-6069 6/03