Evaluation of UPS for intersection traffic signals with LED: findings for TechPower M 1000 UPS

Madhav V. Chitturi, R. F. Benekohal

Research output: Book/Report/Conference proceedingTechnical report


Uninterruptible Power Supply (UPS) systems are used to power the intersection traffic signals that have Light Emitting Diode (LED) signal modules, in case of a power failure. The objective of this study was to test the M 1000 UPS manufactured by TechPower Developments Inc. and verify if it meets the Illinois DOT’s specification for UPS. Multiple tests with full load (approximately 700 W) and partial loads (flashing reds with about 350W) were conducted at room temperature to determine charge and discharge times. The time to fully charge the batteries was consistently greater than 24 hrs. The UPS powered a full load for 2hrs 37mins. When powering a full load, the UPS took 1hr 35min to reach 40% battery level. After reaching the 40% level, the UPS powered the flashing reds for 2hr 10min. TechPower M 1000 UPS has some major and some minor shortcomings that can be corrected to satisfy all IDOT Specification requirements. this model does not have a NO and NC contact closure for indicating that the batteries reached 40% level. The manufacturer gives a 5 hr burn-in period to each unit. The supplied unit was taking approximately 31 hours to fully charge the batteries. The supplied batteries are 55 Amp-hr while the specification requires them to be at least 65 Amp-hr.
Original languageEnglish (US)
Place of PublicationUrbana, Ill
PublisherUniversity of Illinois Urbana-Champaign
StatePublished - 2003

Publication series

NameTraffic Operations Lab Series

Cite this