APPENDIX 5B. T5 MAGNETIC MINIATURE BIPIN BASELINE BALLASTS 

TABLE OF CONTENTS
 

5B.1 INTRODUCTION .........................................................................................................5B-1
 

5B.2 METHODOLOGY AND RESULTS ............................................................................5B-1
 

LIST OF TABLES 

Table 5B.2.1 Common Electronic 2-lamp 4-foot MiniBP T5 SO and HO Ballasts..................5B-1 

Table 5B.2.2 Commercially Available Magnetic and Electronic Ballasts ................................5B-2 

Table 5B.2.3 Model Magnetic and Electronic 2-lamp 4-foot MiniBP T5 SO and HO 

Ballasts .........................................................................................................5B-3
 

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APPENDIX 5B. T5 MAGNETIC MINIATURE BIPIN BASELINE BALLASTS 

5B.1 INTRODUCTION 

Most T5 ballasts are efficient electronic ballasts. During manufacturer interviews, 

several manufacturers expressed concern that less-efficacious T5 ballasts may enter the U.S. 

market if no standard is put into place. One manufacturer in particular stated that a magnetic T5 

ballast might enter the market in the future if T5 ballasts were not covered by standards. Because 

DOE believes that consumers will purchase magnetic 4-foot T5 ballasts without a T5 standard if 

such ballasts are brought to market, DOE developed models of 4-foot T5 standard output (SO) 

and high output (HO) magnetic ballasts as baselines for the SO and HO T5 product classes, 

respectively. This appendix details the development of those models. In particular, DOE 

developed models of a 2-lamp magnetic ballast that operates F28T5 lamps and 2-lamp magnetic 

ballast that operates F54T5HO lamps. 

5B.2 METHODOLOGY AND RESULTS 

To determine the BEF of a magnetic T5 ballast, DOE analyzed the percentage difference 

in BEF for normal ballast factor systems with a similar input power to the T5 system under 

investigation. DOE tested a range of 2-lamp F28T5 and F54T5HO ballasts from multiple ballast 

manufacturers and found that the least efficient but most common ballast exhibited the 

characteristics shown in the table below. The vast majority of F28T5 and F54T5HO ballasts are 

programmed start (PS), electronic, have a high power factor (PF) (>0.98), low total harmonic 

distortion (THD) (<10%), and are universal voltage. Furthermore DOE tested the ballast at 277 

volts (V) as the majority of ballasts operate in commercial buildings at 277V. 

Table 5B.2.1 Common Electronic 2-lamp 4-foot MiniBP T5 SO and HO Ballasts 

For 

Operation 

of 

Starting Method, 

Input Voltage, 

Ballast Type, PF, 

THD 

Ballast 

Factor 

(BF) 

Input 

Power 

(W) 

Ballast 

Efficiency BEF 

2, F28T5 

PS, 277V, Electronic, 

Universal Voltage, 

0.99 PF, <10% THD 

1.02 64.9 87.1% 1.441 

2, F54T5HO 

PS, 277V, Electronic, 

Universal Voltage, 

>0.98 PF, <10% THD 

0.99 124.8 85.4% 0.791 

The input power of the 2-lamp F28T5 ballast is similar in range to the input power of the 

2-lamp F34T12 and F32T8 electronic ballasts (58W and 60W respectively). The input power of 

the 2-lamp F54T5HO is in similar range to the input power of the 2-lamp F96T12/ES electronic 

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ballast (110W).a Because magnetic ballasts are commercially available to operate these lamps, 

DOE was able to determine the percentage difference in input power between magnetic and 

electronic ballasts. Because magnetic ballasts do not exhibit the same BF as electronic ballasts, 

DOE adjusted the input power of the magnetic ballast so that DOE could compare the input 

power directly. The adjusted input power was calculated as follows: 

Electronic AdjustedInputPower = BF * InputPowerMagnetic Equation 5B.2.1 BFMagnetic

AdjustedInputPower = Input Power of Magnetic Ballast adjusted to account for difference in 

ballast factor (BF) 

BFElectronic =BF of electronic ballast 

BFMagnetic =BF of magnetic ballast 

InputPowerMagnetic = Input power of magnetic ballast 

Table 5B.2.2 Commercially Available Magnetic and Electronic Ballasts 

For Operation 

Of Ballast Type BF Input Power Adjusted 

Input Power 

2, F32T8 

Lamps Magnetic 0.95 76 70 

2, F32T8 

Lamps Electronic 0.88 58 58 

2, F34T12 

Lamps Magnetic 0.88 72 71 

2, F34T12 

Lamps Electronic 0.87 60 60 

2, F96T12/ES 

Lamps Magnetic 0.88 126 126 

2, F96T12/ES 

Lamps Electronic 0.88 110 110 

Using the adjusted input power, DOE calculated that the average increase in input power while 

maintaining BF. For the F32T8 and F34T12, the average increase in input power was 20%. For 

the F96T12/ES, the average increase in input power was 15%. DOE applied these percentages to 

the F28T5 and F54T5HO ballasts respectively to determine the input power of the ballast. DOE 

assumed this ballast would exhibit the same BF as its electronic counterpart. The results are 

displayed in the following table. 

a

 Although DOE tested electronic F96T12/ES and F32T8 electronic ballasts, DOE used catalog values because DOE 

chose not to test magnetic F96T12/ES and F32T8 magnetic ballasts. 

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Table 5B.2.3 Model Magnetic and Electronic 2-lamp 4-foot MiniBP T5 SO and HO Ballasts 

For Operation 

Of Ballast Type BF Input Power 

2, F28T5 Magnetic 1.02 77.8 

2, F54T5HO Magnetic 0.99 143.5 

DOE assumed that these magnetic ballasts would exhibit the similar characteristics as their 

electronic counterparts (e.g., these ballasts would be PS) because DOE believes that these 

ballasts would be used as replacements and therefore be in the same product class as their 

electronic counterparts. 

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