Most emergency power system commissioning plans include a generator start-up process that somewhat mirrors NFPA 110, 7.13, and is centered on the generator(s) ability to produce power at varying levels within 10 seconds for a given period of time. Unfortunately that’s where most of the attention is focused with little attention to the subsystems that support and protect the generator(s).
As an example, all too often it is taken for granite that pre-alarms, alarms and shut-downs have been checked at the factory and programming verified for compliance with specifying engineers directions, and not just left in default modes.
Rarely is there a leak in the engine cooling system and therefore a decrease in the level of coolant in the radiator and/or engine block. Unfortunately, the rather stable level of coolant over a period of months or years results in a false sense of security and therefore a decision not to check the coolant level each week.
However, when a lo-coolant level exists it can put patients and staff at risk if the lo-coolant sensor signals for an engine shut down versus an audible alarm. Some engines have been shipped from the factory with a shutdown programmed as a default, and never noticed during commissioning and acceptance testing.
NFPA 110, Table 184.108.40.206 (h) allows two options for remote annunciation – engine shut down, or a remote alarm, for lo-coolant levels.
We suggest a verification of which option has been programmed into the controller or hard wired on older engines. While an engine shutdown option may be preferred when a generator is one of two or more paralleled sets it may not be the best answer in a “stand-alone” design.
A well thought out commissioning plan includes verifying all 12 (13 in some cases) remote alarms are in working order. There are 176 possible points of failure in every EPSS.
In some instances it can take years for a problem to show up and sever the emergency power lifeline. Unfortunately it usually happens when utility power has been unexpectedly lost for indefinite periods of time.