TP-6069 6/03
A-1
Appendix
Appendix A Generator Selection and Wattage Requirements
Consider 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.
Motors
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--3 times higher
than that required when the motor reaches normal
operating speed. Allow reserve for inrush demands plus
other loads which 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
HP
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
Lighting
To calculate 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. Make sure the
calculated total wattage includes only lights actually on
the generator set AC circuit.
Air Conditioners
The starting characteristics of air conditioners vary
greatly; one 12,000 Btu unit has, for example, lower
starting requirements than a 10,000 Btu unit of another
variety. When using only one unit, there is usually no
starting problem, provided the lighting and appliance
load is not too high when starting the unit.
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 use of easy-starting devices on air
conditioner units whenever simultaneously starting
more than one motor.
See Figure 2 for typical air conditioner requirements.
Information will vary with manufacturer.
Appliances
Generator sets often furnish AC for appliances such as
TV, stereo, electric water heater, etc. With the exception
of the resistance-type loads such as the water heater,
requirements for appliances are usually low. Do not
overlook such loads when figuring total requirements.
Allow reserve capacity for anticipated appliance loads to
avoid overloading a generator set.
Air Conditioner Size (Btu/Hr.)
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 Marine Air Conditioner Requirements, 60 Hz
Summary of Contents for 100EFOZ
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Page 10: ...TP 6069 6 03 VI Safety Precautions and Instructions Notes ...
Page 12: ...TP 6069 6 03 2 Section 1 Introduction Notes ...
Page 14: ...TP 6069 6 03 4 Section 2 Location and Mounting Notes ...
Page 20: ...TP 6069 6 03 10 Section 3 Cooling System Notes ...
Page 26: ...TP 6069 6 03 16 Section 4 Exhaust System Notes ...
Page 38: ...TP 6069 6 03 28 Section 6 Electrical System Notes ...
Page 84: ...TP 6069 6 03 74 Section 8 Reconnection Adjustments Notes ...
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