Why an External Maintenance By-Pass Will Save You Money This Year
This is a smart Ups System Buying Practice. When a UPS System is designed and/or budgeted, many consider the External Maintenance By-Pass as an optional “luxury” accessory that is really not necessary, when in fact, it is the opposite. The initial cost of the Maintenance By-Pass, when purchased and installed at the time of the installation, is very affordable and can save a company anywhere from thousands to millions of dollars. After all, in the overall Critical Power support process, one must consider the fact that UPS Systems require routine maintenance and repairs. They are like any other equipment that can and do fail, especially over time or when extraordinary disturbances occur that can damage the equipment from external forces. Thus the oversight in the design process of not installing an External Maintenance By-Pass scheme can result in a client needing to de-energize the entire UPS System in order for technicians to safely carry out a specific repair. Less than ideal.
But what is the External Maintenance By-Pass? Quite simply, it consists of a separate electrical panel away from the UPS itself. The External Maintenance By-Pass panel will consist of a UPS Output Isolation CB, a Maintenance By-Pass CBM and a UPS Input/By-Pass CB. By being external, the critical load can be transferred from the UPS System to the UPS Internal By-Pass, the External Maintenance By-Pass CB is then closed in parallel with the Internal UPS By-Pass CB (make before break) and then the UPS Output Isolation CB is opened, placing all critical loads onto the External Maintenance By-Pass CB, fully isolating all loads from the UPS System, externally and away from the System. The final step is to open the UPS Input/By-Pass CB, effectively isolating the UPS System from all lethal voltages. This allows the user the ability to affect any/all repairs to their UPS System, including removal & replacement, with no down time required.
When purchasing a UPS system, it is crucial to keep in mind the importance of having an external Maintenance By-Pass. Many systems are misrepresented to the purchaser as having a Maintenance By-Pass already installed inside the System. This gives the user the impression that system can be fully isolated from all lethal voltages for repairs and even replacement if necessary. This is only partially factual. What is not evident is that lethal voltages still exist in the UPS, on the Input side and the UPS System cannot be completely isolated from lethal voltage exposure to the technician. Also, it does not allow the user the capability to completely isolate the UPS System from all power, input and output and remove/replace if necessary, as the Cabinets/Cabling are connected and there is back feeding of lethal voltages to the line side of the UPS Static Switch, Input/Rectifier section. In this configuration, some UPS component failures cannot be repaired without shutting down the critical loads.
This year, when considering installing a new or replacement system, think about investing those few extra dollars to save you the problems outlined above and maintain your uninterruptible power supply. The External Maintenance By-Pass will keep you from spending dollars to pick up pennies.
Odyssey Power is here to answer all your questions.