Emergency Generator Commissioning, How to commission a generator
Generator commissioning speaks to what is generator commissioning at the time of installation.
After installation, generator commissioning is required which provides instruction to the owner as to ongoing operation and maintenance procedures which will ensure reliability of the generator system.
The system consists of electrical, mechanical, controls, annunciation and alarm, fuel piping, structural and architectural considerations.
The most common causes of generator failure, is the fuel-supply system because of clogged fuel filters, poor quality diesel fuel or fuel pump failure.
Batteries have to be functioning properly to instantly start the generator.
If jacket water heaters are installed they must be functional to ensure that the generator will start especially in cold temperature areas.
An area of importance is the communication between the automatic transfer switch (ATS) and the generator. The ATS should communicate with the building automation system and motor controllers to ensure large motors and elevators operate and start within their prescribed sequences.
Critical systems that are required to transition loads within 10 seconds, per the National Electrical Codes, require more coordination of the systems and final field commissioning. To ensure that the system generator starts, and that ATS transition within the 10 second, combustion air must be a minimum of 21ºC (70ºF), the jacket water heater must maintain a minimum of 32ºC (90ºF) water temperature and the batteries have to be fully charged.
Generator Commissioning
During commissioning, it is important to verify that all designed sequences are actually occurring in the field start-up.
Annunciators and Alarms
During startup and commissioning the function of annunciators and alarms must be verified. There must be a specific protocol to follow in case of an alarm and the maintenance staff should be thoroughly familiar with the protocol.
These annunciations and alarms include but are not limited to overspeed, overcrank, low fuel, charger malfunction, not-in-auto, high coolant temperature, low coolant temperature, low oil pressure, week battery, load shed and underfrequency.
In addition, if remote fuel fill is required, overfill prevention controls and alarms are essential. Typically these systems provide for continuous level indication and audio and visual alarms at 90% of full fill and system shut off at 95% of full fill (actual percentage settings can be field configured).
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