It is not uncommon for back-up generation to fail in the case of an emergency due to insufficient testing and maintenance. In some cases, nominal run tests can actually create problems within the gensets that can affect operation in a true emergency situation (like wet stacking, where unburned fuel or carbon builds up in the exhaust system when the generator run times are too short or the test is performed outside recommended operating parameters).
The challenge is that comprehensive manual tests are difficult to coordinate and it is equally hard to effectively measure results. There are major challenges for multiple stakeholders in the hospital, including medical personnel, facility personnel, and the hospital administration. In short, manual testing of EPS systems is costly and inefficient.
The testing of emergency power supply systems (EPSS) in hospitals, data centers, and other critical buildings plays an essential role to ensure backup power is available when needed. This testing is usually done weekly or monthly and depending on the jurisdiction, different regulatory bodies dictate the parameters of the test. Most commonly, diesel engines are used as prime movers for emergency power supply generators. While diesel engines are known for their reliability and fuel efficiency, it is critical that the testing is carried out within certain limits to make sure that the reliability is increased rather than decreased as a result of the testing.
Traditionally, EPSS testing has been carried out using stop watches and manual recording of test parameters. Manual test procedures are time-consuming and tie up a significant number of personnel. Ignoring actual generator operating temperatures can lead to a wet-stacking condition, in which the presence of unburned fuel or carbon in the exhaust system of a generator can result in black smoke being emitted while the engine is running. Wet-stacking can occur over a prolonged period by running the engine at low loads, allowing the engine to idle during a test, or installing an oversized engine. Eventually, irreversible engine damage can occur.
Improper or incomplete EPSS testing can lead to a significant loss of revenue for a hospital or critical building, or, at worst, to a loss of human life. What is needed is an automated EPSS system that avoids these and other problems.