RESIDENTIAL TRANSFORMER LOADING GUIDELINES
PEAK KW DEMAND REQUIREMENTS ON PEAK DAYS
Electric
Summer
Electric
Winter
Gas
Summer
Gas
Winter
DIVERSITY TABLE
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INITIAL AND MAXIMUM KVA LOADING
SINGLE PHASE RESIDENTIAL OVERHEAD AND PAD MOUNTED TRANSFORMERS
Transformer
Size
Summer
140%
Winter
160%
Transformer
Size
Summer
140%
Winter
160%
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Underground Residential Transformer Loading Guide
Homes Between 700 and 1,200 Square Feet
Number of
Electric
Number of Gas Customers
Customers
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
0
0
25
25
25
25
25
25
25
50
50
50
50
50
50
50
50
50
100
100
100
100
1
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25
25
25
25
25
50
50
50
50
50
50
50
50
100
100
100
100
100
100
2
25
25
25
25
50
50
50
50
50
50
50
50
100
100
100
100
100
100
100
3
25
25
25
50
50
50
50
50
50
50
50
100
100
100
100
100
100
100
4
25
50
50
50
50
50
50
50
50
100
100
100
100
100
100
100
100
5
50
50
50
50
50
50
50
100
100
100
100
100
100
100
100
100
6
50
50
50
50
50
100
100
100
100
100
100
100
100
100
100
7
50
50
50
100
100
100
100
100
100
100
100
100
100
100
8
50
50
100
100
100
100
100
100
100
100
100
100
100
9
100
100
100
100
100
100
100
100
100
100
100
100
10
100
100
100
100
100
100
100
100
100
100
100
11
100
100
100
100
100
100
100
100
100
100
12
100
100
100
100
100
100
100
100
100
13
100
100
100
100
100
100
100
100
14
100
100
100
100
100
100
100
15
100
100
100
100
100
167
16
100
100
100
167
167
17
167
167
167
167
18
167
167
167
19
167
167
20
167
Underground Residential Transformer Loading Guide
Homes Between 1,200 and 1,500 Square Feet
and Single Wide Mobile Homes
Number of
Electric
Number of Gas Customers
Customers
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
0
0
25
25
25
25
25
50
50
50
50
50
50
100
100
100
100
100
100
100
100
100
1
25
25
25
25
25
50
50
50
50
50
50
100
100
100
100
100
100
100
100
100
2
25
25
25
50
50
50
50
50
50
100
100
100
100
100
100
100
100
100
100
3
50
50
50
50
50
50
50
100
100
100
100
100
100
100
100
100
100
100
4
50
50
50
50
50
50
100
100
100
100
100
100
100
100
100
100
100
5
50
50
50
50
100
100
100
100
100
100
100
100
100
100
100
100
6
50
50
50
100
100
100
100
100
100
100
100
100
100
100
100
7
50
100
100
100
100
100
100
100
100
100
100
100
100
100
8
100
100
100
100
100
100
100
100
100
100
100
100
167
9
100
100
100
100
100
100
100
100
100
100
167
167
10
100
100
100
100
100
100
100
100
167
167
167
11
100
100
100
100
100
167
167
167
167
167
12
100
100
100
100
167
167
167
167
167
13
100
167
167
167
167
167
167
167
14
167
167
167
167
167
167
167
15
167
167
167
167
167
167
16
167
167
167
167
167
17
167
167
167
167
18
167
167
167
19
167
167
20
167
Underground Residential Transformer Loading Guide
Homes Between 1,500 and 1,800 Square Feet
Number of
Electric
Number of Gas Customers
Customers
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
0
0
25
25
25
25
25
50
50
50
50
50
100
100
100
100
100
100
100
100
100
100
1
25
25
25
25
50
50
50
50
50
100
100
100
100
100
100
100
100
100
100
100
2
25
25
50
50
50
50
50
50
100
100
100
100
100
100
100
100
100
100
100
3
50
50
50
50
50
50
50
100
100
100
100
100
100
100
100
100
100
100
4
50
50
50
50
50
100
100
100
100
100
100
100
100
100
100
100
100
5
50
50
50
100
100
100
100
100
100
100
100
100
100
100
100
167
6
50
50
100
100
100
100
100
100
100
100
100
100
100
167
167
7
100
100
100
100
100
100
100
100
100
100
100
100
167
167
8
100
100
100
100
100
100
100
100
167
167
167
167
167
9
100
100
100
100
100
100
100
167
167
167
167
167
10
100
100
100
100
167
167
167
167
167
167
167
11
100
100
100
167
167
167
167
167
167
167
12
167
167
167
167
167
167
167
167
167
13
167
167
167
167
167
167
167
167
14
167
167
167
167
167
167
167
15
167
167
167
167
167
167
16
167
167
167
167
167
17
167
167
167
167
18
167
167
167
19
167
167
20
167
Underground Residential Transformer Loading Guide
Homes Between 1,800 and 2,400 Square Feet
Number of
Electric
Number of Gas Customers
Customers
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
0
0
25
25
25
25
50
50
50
50
50
100
100
100
100
100
100
100
100
100
100
100
1
25
25
25
50
50
50
50
50
50
100
100
100
100
100
100
100
100
100
100
100
2
25
50
50
50
50
50
50
100
100
100
100
100
100
100
100
100
100
100
100
3
50
50
50
50
50
50
100
100
100
100
100
100
100
100
100
100
100
100
4
50
50
50
50
100
100
100
100
100
100
100
100
100
100
100
100
167
5
50
50
50
100
100
100
100
100
100
100
100
100
100
100
100
167
6
50
100
100
100
100
100
100
100
100
100
100
100
100
167
167
7
100
100
100
100
100
100
100
100
100
100
167
167
167
167
8
100
100
100
100
100
100
100
100
167
167
167
167
167
9
100
100
100
100
100
167
167
167
167
167
167
167
10
100
100
100
100
167
167
167
167
167
167
167
11
100
167
167
167
167
167
167
167
167
167
12
167
167
167
167
167
167
167
167
167
13
167
167
167
167
167
167
167
167
14
167
167
167
167
167
167
167
15
167
167
167
167
167
167
16
167
167
167
167
167
17
167
167
167
167
18
167
167
167
19
167
167
20
167
Underground Residential Transformer Loading Guide
Homes Between 2,400 and 3,000 Square Feet
Number of
Electric
Number of Gas Customers
Customers
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
0
0
25
25
25
25
50
50
50
50
100
100
100
100
100
100
100
100
100
100
167
167
1
25
25
25
50
50
50
50
100
100
100
100
100
100
100
100
100
100
100
167
167
2
25
50
50
50
50
50
100
100
100
100
100
100
100
100
100
167
167
167
167
3
50
50
50
50
100
100
100
100
100
100
100
100
100
100
167
167
167
167
4
50
50
50
100
100
100
100
100
100
100
100
100
167
167
167
167
167
5
100
100
100
100
100
100
100
100
100
100
100
167
167
167
167
167
6
100
100
100
100
100
100
100
100
167
167
167
167
167
167
167
7
100
100
100
100
100
100
167
167
167
167
167
167
167
167
8
100
100
100
167
167
167
167
167
167
167
167
167
167
9
167
167
167
167
167
167
167
167
167
167
167
167
10
167
167
167
167
167
167
167
167
167
167
167
11
167
167
167
167
167
167
167
167
167
167
12
167
167
167
167
167
167
167
167
167
13
167
167
167
167
167
167
14
167
167
Demand Factors
1. General The following definitions:
a. Demand The value of electrical power required for a particular load. Generally
stated as maximum demand required and is expressed in kW. The maximum
demand is usually the integrated maximum demand over a 15 or 30-minute
interval rather than the instantaneous or peak demand.
b. Demand Factor The ratio of the maximum demand on a system to the total
connected load of the system.
c. Diversity Factor The ratio of the maximum demand of the whole system to the
total of the individual maximum demands of the components of the system.
Diversity factor is always less than unity.
2. Published Demand Factors
Motors
(general purpose - machine tool ventilation, compressors, pumps,
rolling mills, etc.)
30%
Motors (semi-continuous operations - paper mills, refineries,
rubber mills)
60%
Motors (continuous operations - textile mills)
90%
Electric ovens, heaters, furnaces
80%
Induction furnaces
80%
Arc furnaces
100%
Arc welders
30%
Resistance welders
20%
3. Typical Demand Factors
a. Refrigeration and A/C
(1) Package (0-10 tons)
(2) Package (10 -25 tons)
(3) Package (25-50 tons)
(4) Package (50-100 tons)
(5) Package (100 and up)
(6) Centrifugal (200 tons & up)
(7) Centrifugal (all auxiliaries)
1.6 kW / ton
1.4 kW / ton
1.2 kW / ton
1.1 kW / ton
1.0 kW / ton
0.6 - 0.9 kW / ton (compressor only)
0.7 - 0.8 (connected kW)
b. Textile
(1) Cotton Mills
(2) Synthetics
(3) Knitting
0.6 (connected HP)
0.5 (connected HP)
0.5 (connected HP)
c. Furniture
d. Metalworking
(1) Heavy Manufacturing
(2) Light Manufacturing
0.4 - 0.45 (connected HP)
0.2 - 0.3 (connected HP)
e. Sawmills
0.3 - 0.4 (connected HP)
f. Arc Welders
0.2 - 0.3 (nameplate kVA or kW)
g. Spot Welders
0.1 - 0.15 (nameplate kVA or kW)
h. Lighting
1.0
I. Resistance Heat
(1) Environmental
(2) Process
j.
Asphalt Plant
0.45 (connected HP)
0.4 - 1.0
0.4 - 0.6
0.8
k. Rock Quarry
0.4 - 0.6
l.
1.0
Electric Melting
m. Air Compressor
0.3 - 0.8
Estimating Customer Demand Factors
Background
To begin this section, one should have a basic understanding of metering and know the
difference between kW and kWh. One should also be able to calculate the kW from HP,
Tons, BTUh, and Amps and Volts.
Demand Estimation
Demand is defined as the rate of energy consumption during a specific time period.
Many utilities use 60-minutes, 30-minutes, or 15-minutes. Some utilities may use a
rolling 5-minute interval. Why should we be concerned with this interval maximum rate?
This interval maximum determines the size of a utilities generation facilities, distribution
systems, and the transformer size at the customer’s location.
Let us think about our own personal residence for a moment. Let’s list the electrical
loads in our home.
Range
Electric Heater
Air Conditioner
Television
Refrigerator
Water Heater
Lights
Hair Dryer
Toaster
Dishwasher
Microwave
Washing Machine
Clothes Dryer
8,000 watts
8,000 watts
4,000 watts
700 watts
750 watts
4,500 watts
2,500 watts
1,500 watts
750 watts
2,000 watts
1,000 watts
250 watts
5,000 watts
Total Connected Load
38,950 watts
If all of these loads in our home stayed on all month, our personal electric bills would be
almost $2,000 per month. No one could afford to build electric generation facilities to
meet this type of demand. Obviously, all of these loads do not operate at the same
time, therefore, these loads have “diversity”. The heating and air conditioning in the
home do not operate simultaneously, the television is not always on, we do not wash
clothes twenty-four hours a day. These are the elements which go into making up load
diversity.
The maximum demand on your house will probably never exceed 12 kW. Therefore,
the diversity factor for your home would be 12 kW / 38.95 kW = 0.31 or 31% diversity.
Knowing how loads interact and being able to figure their contribution to the maximum
demand is essential for sizing contracts.
How does one develop a reasonable demand estimate of a customer? Do we let the
customer or the consulting engineer tell us (the utility) what his demand level is going to
be? Not usually. This is normally the worst method of deriving a maximum demand.
The typical consulting engineering is not concerned with how much the utility has to
spend to provide service, he is concerned with insuring the service is more than
adequate to serve a particular load.
However, the customer, the consulting engineer, or both are the best sources to get us
started. They can provide the best insight into the type of load, the size of the load, the
time and season in which the load operates. All of this information plus good common
sense will start one down the road to estimating the demand level. Now that we have
the benefit of the information the customer has provided us, let’s separate the load into
two basic groups. These are base loads and weather responsive loads. These two
groups are broad groups into which all loads can be divided. The base load group
covers all loads used without respect to weather conditions. Some load types in this
group are lighting, motors, food service, water heating, receptacle load, and business
machines. The second broad group is composed of whether responsive loads which
are heating and air conditioning. This group is of great concern to the utility since their
peak will usually occur on the hottest day or coldest day of the year and the utility must
have sufficient generation, distribution facilities, and transformers even for that short
period of time.
Base loads and whether responsive are two broad groups into which we must first
divide our loads. Once this is done, a closer look at each element within these groups
can be made.
Lighting (interior) is considered a base load and is essential in all types of business.
Lighting has a very high diversity factor, usually in the range of 85 to 90 percent. It will
seldom be 100 percent because someone will always be out of the office, burned out
lamps will not be replaced, or lamps in closets will not be on.
Lighting (exterior) is not usually considered in calculating maximum interval demand
levels. This is due to the fact that this light usually is on only at night when other
demands are low. The exception to every rule is a ballpark or tennis court which is
usually the only load or biggest load on the delivery.
Water Heating is considered a base load and has a wide of range of diversity. Water
heating load associated with restrooms in office buildings could reflect in the range of 0
to 5 percent. However, water heating associated with food service or laundries could
have a diversity of 10 to 40 percent. In some instances the diversity could be as high as
100 percent.
Food Service load is considered a base load and is one of the more difficult to predict in
its effect on demand. This type of load could range from a small kitchen unit in an office
building to a professional bake shop. To give one a range in which to begin for
commercial heavy used kitchens, the range of diversified load should fall between 25
and 40 percent.
Receptacles are considered base load and should be diversified from 0 to no more than
10 percent. This type load includes typewriters, computers, desk lamps, coffee pots,
calculators, radios, and other receptacle load.
Space Heating, whether provided by heat pumps, resistance, or radiant heat, are
considered weather responsive loads. These heaters are usually controlled by some
type of thermostat which controls how often and how long these units will run. In most
North Carolina service areas, the design temperature is between 10oF and 25oF, which
means if a unit is properly sized it will not run all of the time until the outside
temperature reaches 10oF to 25oF. However, heating units are usually oversized, and
people, lights, and other loads give off heat; therefore, the full capacity of installed units
is rarely on all the time. Space heating and interior lighting directly complement each
other. If the total heat loss of the structure is 8 watts per square foot and 10 watts of
heat per square foot has been installed, plus an additional 2½ watts per square foot of
interior lighting, and both heat and lights are on, it is obvious that the thermostats will be
satisfied on the heating system before the full 10 watts per square foot of heat is
reflected on the meter, unless a possible combination of cold start-up and severe
weather exists.
Air Conditioning is another weather responsive load. It is very important to keep
seasonal loads separate. Therefore, it will be necessary to calculate both summer
demand level and a winter demand level to determine which is greater. If air
conditioning is installed, it is usually designed to maintain 75oF to 78oF inside when the
temperature outside is 95oF. On most buildings, one will need to use 100 percent
diversity unless drastic over sizing is noted. Air conditioning and interior lighting directly
“buck” or “fight” each other. This is the opposite effect of combined heating and lighting.
Other Loads could be either weather responsive or base load depending upon the use
of the load. Examples of other loads that one will find in buildings are as follows:
Elevators
Service elevators are used to move people at peak periods.
Therefore, a diversity of 0 to 25 percent could be used. (Usually 0
percent in large buildings.)
Computers
Are these small computers that are or machines used by the entire
company 24 hours per day?
Motors
They can be used to move either air or products. They can be
used 24 hours per day or one hour a week.
These and other loads are all going to have to be identified by you and a judgement
made on their contribution to a peak demand. If assistance is required, one should
search out good advice from other sources.
This is merely the first step in demand estimation. Once a summer and winter peak has
been established, one should use every method available to assure the proper contract
demand. This means using other methods of demand estimation to check the
calculation.
One of these methods is a watts per square foot method. One simply takes the watts
per square foot historically used by the same type of structure and multiples the watts
per square foot times the square footage of the structure in question. The kW demand
one obtains with the watts per square foot method should closely correspond to the
diversification you perform. If this is not true, one should investigate the diversity factors
that were used.
A second method used to check the diversification of loads is the percent of connected
load method. With this method, one must first sum all of the loads for each season.
Then, take the percent of reflected load historically used by the same type of structure,
multiplied by the connected load. Here again, if the projected kW demand is not close
to the diversified method, one should investigate.
The last, and probably the best method of checking your projected demand is the
comparable building method. This is used when you know that the builder is using a
standard set of plans which are used with only minor modifications for all of their
company’s stores; much like Family Dollar Stores, Wal-Mart Stores, and others. With
this type of structure, one should find the billing history on a store similar to the one
being built and see what the demand levels have been running.
Future Load - The contract is normally set for the anticipated demand level to be
reached during the original term of the contract. Often, the customer will indicate that
growth is anticipated beyond this original term, and another decision has to be made;
whether to install a transformer ample for present day loads or suitable for future
conditions. Each delivery should be judged in its respect on its own set of conditions;
such as the customer’s financial position, historical development trends, state of the
economy, etc.
This should enable one to accurately project demand and speak to customers
intelligently on high bill complaints. However, remember the two biggest tools in
estimating demand levels are good information and good common sense.
Actual Watts per Square Foot Averages & % Connected Load Averages
Watts / Foot2
% Connected Load
Winter a
Summer
Winter
Summer b
Banks
9.2
6.3
41%
53%
Offices
7.7
6.4
32%
53%
Churches
9.7
6.2
43%
59%
Convenience Stores
13.0
12.7
45%
93%
Department Stores
6.9
5.6
46%
82%
Medical Clinics
11.3
8.6
44%
69%
Grocery Stores
10.1
10.4
45%
61%
Restaurants (Fast Food)
45.8
41.5
37%
39%
Restaurants (Family)
27.3
21.9
44%
52%
Variety Stores
10.2
7.1
51%
81%
Schools
10.2
5.6
43%
48%
Motels
7.6
4.6
34%
52%
a - Structures with electric space heating
b - Less connected heat kW
The number of samples used to obtain these figures is not large enough to be
considered absolute - use as general guidelines only.
Range of Watts per Square Foot Averages & % Connected Load Averages
Watts / Foot2
% Connected Load
Winter a
Summer
Winter
Summer b
Banks
7 - 11
4-8
35 - 45%
50 - 60%
Offices
6 - 10
5.5 - 7.5
25 - 40%
40 - 60%
Churches
8 - 11
4.5 - 7.5
40 - 50%
55 - 65%
Convenience Stores
11 - 15
10.5 - 14.5
40 - 50%
88 - 98%
Department Stores
6 - 7.5
4.5 - 6
35 - 55%
70 - 90%
Industrial (Process)
6 - 12
6 - 12
40 - 65%
40 - 65%
Medical Clinics
8 - 14
6.5 - 10.5
35 - 55%
60 - 80%
Grocery Stores
9 - 12
9 - 12
35 - 55%
50 - 70%
Restaurants (Fast Food)
30 - 60
30 - 60
35 - 50%
30 - 50%
Restaurants (Family)
17 - 37
16 - 30
35 - 55%
40 - 60%
Variety Stores
8 - 12.5
5.5 - 9
40 - 60%
75 - 95%
Schools
10 - 12
5-7
35 - 55%
40 - 60%
Motels
5 - 11
3.5 - 5.5
30 - 40%
50 - 70%
a - Structures with electric space heating
b - Less connected heat kW
The number of samples used to obtain these figures is not large enough to be
considered absolute - use as general guidelines only.
GUIDELINES FOR DETERMINING WHETHER A COMMERCIAL
CUSTOMER’S EXPECTED DEMAND WOULD BE GREATER OR LESS
THAN 15 KW
To help you determine whether a customer’s expected demand would be greater than
15 kW, first obtain from the customer the conditioned square footage of the location
involved. (Conditioned square footage is the area of the building that is either heated or
cooled.) Then multiply the watts per square foot (as listed below for different types of
businesses) by the conditioned square footage of the location to determine the
approximate load in watts. Divide by 1000 to convert this figure to kilowatts.
Remember that if the customer has electric heat, use the amount in the “Winter”
column. If the does not heat electrically, use the amount in the “Summer” column
(based on air conditioning load). If the customer does not have electric heat or air
conditioning, this chart is not applicable.
Watts / Foot2
Winter
Summer
Banks
9.2
6.3
Offices
7.7
6.4
Churches
9.7
6.2
Convenience Stores
13.0
12.7
Department Stores
6.9
5.6
Medical Clinics
11.3
8.6
Grocery Stores
10.1
10.4
Restaurants (Fast Food)
45.8
41.5
Restaurants (Family)
27.3
21.9
Variety Stores
10.2
7.1
Schools
10.2
5.6
Motels
7.6
4.6
Note: Most small auxiliary accounts such as workshops, well pumps, etc., would have a
kW demand of less than 15 kW.
The number of samples used to obtain the figures listed above is not large enough to be
considered absolute. It should be used as a general guideline only.
MOTOR DATA
HP
AVERAGE EFFICIENCY, %
KW
1/20
40
0.09
1/12
49
0.12
1/8
55
0.17
1/6
60
0.21
¼
65
0.29
1/3
66
0.37
½
65
0.57
3/4
72
0.78
1
79
0.94
1½
79
1.42
2
79
1.89
3
84
2.66
5
84
4.44
7½
85
6.58
10
87
8.57
15
87
12.86
20
87
17.15
25
87
21.44
30
89
25.15
40
89
33.53
50
89
41.91
60
90
49.73
75
91
61.48
100
91
81.98
125
91
102.47
150
91
122.97
200
91
163.96
INPUT POWER OF PACKAGE A/C AND REFRIGERATION UNITS
TONNAGE
TOTAL SYSTEM INPUT
INCLUDING AUXILIARIES
PACKAGE UNITS 0 - 10 TONS
1.6 KW / TON
PACKAGE UNITS 11 - 25 TONS
1.4 KW / TON
PACKAGE UNITS 26 - 50 TONS
1.2 KW / TON
PACKAGE UNITS 51 - 100 TONS
1.1 KW / TON
PACKAGE UNITS 101 TONS & UP
1.0 KW / TON
CENTRIFUGAL
1.0 KW / TON
Multiply the number of tons times the number of kW per ton.
For Example:
1.
2.
3.
2 tons:
11 tons:
27 tons:
2 tons x 1.6 kW / ton = 3.2 kW
11 tons x 1.4 kW / ton = 15.4 kW
27 tons x 1.2 kW / ton = 32.4 kW
BTU’S PER HOUR AND TONS CONVERSION
BTU’S PER HOUR
TONS
12,000
1
18,000
1½
24,000
2
30,000
2½
36,000
3
42,000
3½
48,000
4
54,000
4½
60,000
5
AVERAGE RANGE OF DIVERSITY FACTORS FOR SERVICE LOCATIONS
Lighting (exterior)
0%
Lighting (interior)
85% - 90%
Base Load
0% - 10%
Water Heating:
Domestic
Sanitary
0% - 10%
10% - 40%
Food Service:
Small Facility
Regular Restaurant
Fast Food
0% - 10%
25% - 40%
50% - 60%
Heating
8 watts / square foot minus lighting load or 100%
Cooling
Motors:
Process
100%
Commercial
Industrial
25% - 30%
10% - 65%
30% - 65%
LUMENS PER WATT FOR HID SOURCES WITH AND WITHOUT BALLAST LOSSES AND AT 70% OF LIFE
A
B
C
D
E
F
G
H
With Ballast
Losses
Total
Lamp Type
Lamp
Wattage
Initial
Lumens
LDD @ 70%
of Life
Lumens @
70% of Life
Wattage
with Ballast
LPW
Initial
LPW @ 70%
of Life
Life
(Hours)
1
Mercury DX
100
4,200
0.63
2,646
127
42.0
20.8
24,000 +
2
Mercury DX
175
8,600
0.78
6,708
205
49.1
32.7
24,000 +
3
Mercury DX
250
12,100
0.74
8,954
290
41.7
30.9
24,000 +
4
Mercury DX
400
22,500
0.71
15,975
450
50.0
35.5
24,000 +
5
Mercury DX
1000
63,000
0.52
32,760
1070
58.0
30.6
24,000 +
6
Metal Halide
175
14,000
0.72
10,080
210
66.7
48.0
7,500
7
Metal Halide
250
20,500
0.71
14,555
300
68.3
48.5
10,000
8
Metal Halide
400
34,000
0.70
23,800
455
74.7
52.3
20,000A
9
Metal Halide (Super)
400
40,000
0.70
28,000
455
87.9
61.5
15,000
10
Metal Halide
1000
110,000
0.73
80,300
1075
102.3
74.7
12,000
11
Metal Halide (Super)
1000
125,000
0.73
91,250
1075
116.3
84.9
12,000
12
High Pressure Sodium
70
5,800
0.83
4,814
88
65.9
54.7
24,000 +
13
High Pressure Sodium
100
9,500
0.83
7,885
130
73.1
60.7
24,000 +
14
High Pressure Sodium
150
16,000
0.83
13,280
188
85.1
70.6
24,000 +
15
High Pressure Sodium
250
27,500
0.83
22,825
300
91.7
76.1
24,000 +
16
High Pressure Sodium
400
50,000
0.83
41,500
465
107.5
89.3
24,000 +
17
High Pressure Sodium
1000
140,000
0.77
107,800
1100
127.3
98.0
24,000 +
A - 20,000 hours if operated  15% of vertical, otherwise 15,000 hours
COMPARISON OF PERFORMANCE FOR INCANDESCENT VS. LOW WATTAGE FLUORESCENT AND HID SOURCES
A
B
C
D
E
F
G
H
With Ballast
Losses
Total
Lamp
Wattage
Initial
Lumens
LDD @ 70%
of Life
Lumens @
70% of Life
Wattage
with Ballast
LPW
Initial
LPW @ 70%
of Life
Life
(Hours)
22
870
0.70
609
22
39.6
27.7
16,000
44
1,750
0.70
1,225
44
39.8
27.8
7,500
161
850
0.70
595
16
53
37.2
7,500
441
1,750
0.70
1,225
44
39.8
27.8
7,500
Twin Tube Fluorescent
7
400
0.68
272
12*
33.3
22.6
10,000
(PL Lamps)
9
600
0.70
420
12
50.0
35.0
10,000
13
900
0.70
630
17
52.9
37.1
10,000
35
2,250
0.83
1,868
45
50.0
41.5
24,000 +
50
4,000
0.83
3,320
63
63.5
52.7
24,000 +
70
5,800
0.83
4,814
87
66.7
55.3
24,000 +
60
870
0.86
748
60
14.5
12.5
1,000
A-19 ES
67
1,130
0.86
972
67
16.9
14.5
750
A-19
75
1,190
0.86
1,023
75
15.9
13.6
750
A-19
100
1,750
0.86
1,505
100
17.5
15.0
750
A-21
150
2,850
0.86
2,451
150
19.0
16.3
750
A-23
200
4,010
0.86
3,449
200
20.1
17.2
750
Lamp Type
Circlite
HPS (Clear)
Incandescent2
A-19
3
1 - 2-Way Lamp (16-44W)
2 - Incandescent Lamps are Inside Frosted
3 - Energy Saving Incandescent
* - With Multi-tap ballast
Note: Circlite, Twin Tube Fluorescent, and HPS lamps are usually lower power factor (30-60%). This should be considered in equipment sizing.