Fire pumps are usually started in the following ways:
First, the fire pump control cabinet in the water pump room starts the pump directly.
second, the multi-line module of the fire alarm host is started, and there is a multi-line control panel on the panel of the alarm host with the corresponding start and stop buttons, which is the first case you mentioned.
thirdly, the pump can be started and stopped depending on the change of pipe network pressure, including electric contact pressure gauges and pressure switches. This is the third situation you mentioned.
fourth, in the second case where you have the biggest doubt, the remote pump start button of the fire control center starts the pump. The usual practice is to set up a small remote pump start control box in the fire control center, which is 22V, and each pump corresponds to a button instead of a cabinet corresponding to a button. The function is equivalent to the fire hydrant button. This startup method is required by the fire acceptance code, and of course it can pass the fire acceptance.