Kohler 13ERG User Manual download pdf (Page 47)

TP-6335 9/04 Appendix A-1

Appendix A Generator Selection and Wattage Requirements

General Wattage Requirements

Consider the total wattage requirements (lights, motors,

appliances) when selecting a generator set, or when

sizing wattage usage in which available space and

construction limit the size of the generator set.

Motor Loads

When figuring generator set capacity requirements for

loads that include electric motors, consider the high

current demanded by the motors during startup. The

inrush or starting current is typically 2 to 3 times higher

than that required when the motor reaches normal

operating speed. Allow a reserve for inrush demands

plus other loads that could be on the line as the electric

motor starts. Use Figure 1 as a guide when selecting

generator set capacity requirements involving motor

loads.

Motor

Starting

(Inrush)

Watts

Running

Watts

1/4 750 330

1/3 1000 400

1/2 1500 600

3/4 2000 750

1 3300 1100

2 4000 2000

3 5000 3000

Figure 1 Motor Requirements

Appliance Loads

Generator sets often furnish AC for appliances such as

TVs, stereos, and electric water heaters. Except for the

resistance-type loads such as the water heater, the

requirements for appliances are usually low. Do not

overlook such loads when figuring the total

requirements. Allow a reserve capacity for anticipated

appliance loads to avoid overloading a generator set.

Lighting Load

To calculate the lighting load, add the wattage of each

generator set-operated lamp. Note that not all of the

lights or lamps are on the generator set AC

circuit—some are DC powered by a 12-volt battery.

Ensure that the calculated total wattage includes only

lights actually on the generator set AC circuit.

Air Conditioners

The starting characteristics of air conditioners vary

greatly—for example, one 12,000 Btu unit has lower

starting requirements than a 10,000 Btu unit of another

variety. When using only one unit, there is usually no

starting problem provided that the lighting and appliance

load is not too high when starting the generator set.

Simultaneous starting of two air conditioning units,

however, can present problems if the generator set

capacity is marginal. Because of the variation in starting

characteristics among air conditioners, this publication

makes no statements regarding multiple-motor starting

capabilities of the generator set covered. Consider

delayed starting or the use of easy-starting devices on

air conditioner units whenever simultaneously starting

more than one motor.

See Figure 2 for typical air conditioner requirements.

The requirements vary among different manufacturers.

Air Conditioner Size (Btu)

7,000 9,000 12,000 16,000 24,000

Voltage 115 230 115 230 115 230 115 230 230

Full load amps 9.3 4.8 9.9 5.0 11.8 6.3 16.3 8.0 11.6

Rated load amps 7.7 4.0 7.0 3.5 8.9 4.8 13.0 6.2 10.2

Locked rotor amps 34.0 20.0 40.0 20.0 50.0 31.0 75.0 36.0 56.0

Starting (inrush) watts 3910 4600 4600 4600 5750 7130 8630 8280 12,900

Running watts 886 920 805 805 1020 1100 1500 1430 2350

Figure 2 Typical Air Conditioner Requirements (60 Hz)

1 2 ... 42 43 44 45 46 47 48 49 50 51 52

Comments to this Manuals

No comments

Kohler 13ERG User Manual Page 47

Comments to this Manuals

Related products and manuals for Generators Kohler 13ERG