Effect of High and Low Temperatures on UPS systems for Intersection Traffic Signals

Chitturi, Madhav V.; Benekohal, Rahim F.

Permalink

https://hdl.handle.net/2142/46017 Copy

Description

Title

Effect of High and Low Temperatures on UPS systems for Intersection Traffic Signals

Author(s)

• Chitturi, Madhav V.
• Benekohal, Rahim F.

Issue Date

2005-09

Keyword(s)

Uninterruptible Power Supply for Intersections, UPS, Intersection Traffic Signals, LED Signal Modules, Battery Back up System for Traffic Lights, BBS.

Abstract

Temperature significantly affects the performance of UPS systems. Four different UPS systems were evaluated at sub-zero temperatures and hot temperatures from -25 °C to +72 °C (-13 °F to +162 °F). At high temperatures, tests were performed to ascertain the run times under normal signal operation, whether the UPS shutsdown the charging and that there is no gassing of the batteries. At sub-zero temperatures tests were performed to find the run times under normal, flashing and a combination of normal and flashing modes of operation. All the UPS systems showed longer run times as the temperature increased and drastically shorter run times as the temperature decreased. For normal operation at +72 °C condition, the percentage change in run time relative to room temperature ranged from +6% to +26%. Relative to room temperature the percentage change in run time at -25 °C condition ranged from -32% to -80% for normal operation. At the coldest temperature, the increase in duration of flashing compared to duration of normal operation ranged from 89% to 158% and the increase in combination of normal and flashing duration compared to normal operation duration ranged from 35% to 81%. It is recommended to switch to flashing or a combination of normal and flashing mode of operation in cold temperatures to increase the run time. It was also found that a UPS with a greater battery capacity may not yield greater run times under all temperature conditions.

Series/Report Name or Number

FHWA-IL/UI-TOL-17

ISSN

0917-9191

Type of Resource

text

Language

en

Permalink

http://hdl.handle.net/2142/46017

Sponsor(s)/Grant Number(s)

The Illinois Department of Transportation

Copyright and License Information

No restrictions. This document is available to the public through the National Technical Information Service, Springfield, Virginia 22161

Owning Collections