UL - Underwriters' Laboratories This private organization was originally founded as a result of the need for insurance companies to help consumers choose safe electrical and safety equipment. UL evaluates equipment submitted to them by the equipment manufacturer using standards, which UL has written for the equipment category. Equipment, which is evaluated and found to meet the safety requirements, is either UL Listed or UL recognized. Many insurance companies and local electrical codes in the US require that installed electrical equipment be UL Listed. http://www.ul.com
UL Approved This is a widely used term that is technically not correct. The correct terms are UL LISTED or UL RECOGNIZED.
UL Listed UL grants this form of approval to equipment that will be user installed or operated and that is found to meet the safety requirements of the applicable UL standards. If a product is UL Listed, then it must be marked with the UL symbol.
UL Recognized This is a form of formal approval granted by UL to devices that are not used as free standing equipment on their own, but are to be installed into some other system by a manufacturer, electrician, or possibly by an end-user.
UL2601-1 The safety requirements specified by Underwriters Laboratories Inc. that cover electrical medical and dental equipment that is intended for professional use by personnel in hospitals, nursing homes, medical care centers, medical and dental offices and similar health care facilities. These requirements cover portable equipment rated at 300 V or less and permanently connected equipment rated at 600 V or less.
UPS - Uninterruptible Power Source A power supply which continues to supply power during a loss of input power. Two types are the stand-alone UPS, which is located external to the equipment being powered, and the battery back-up power supply, which is embedded in the equipment being powered, such as a POWER-ONE SAM series high power product with a G5 battery back-up module.