Self-inspection methods provide a way to perform daily checks on fire pumps in fire water supply systems. During fire pump self-inspection, not only can rust and seizure of the fire pump be prevented, but alarms can also be triggered for motor overload, short circuit, overvoltage, phase loss, undervoltage, and overheating. Fire pump self-inspection is a technological advancement that improves system management. Both fire pump self-inspection methods demonstrate the maintenance role of self-inspection for fire pumps, but the low-speed self-inspection method only runs a primary stage of the fire pump startup and cannot fully reflect the actual operating conditions of the fire pump in the future. In addition, after the results of the fire pump self-inspection are fed back to the fire control center, further judgment is required by personnel. Therefore, the fire pump self-inspection method cannot completely replace manual maintenance and management of the fire pump.
Analysis of Self-Inspection Methods
The constant-speed self-inspection method simulates the actual operating conditions of fire water supply within a certain period. It checks the entire process of fire pump startup and normal operation. However, improvements are needed in pipeline design. Most importantly, it is necessary to prevent solenoid valve failures in the bypass pipeline; the valve must be opened during self-inspection and closed promptly after completion. The low-speed self-inspection method does not require modifications to the fire pump pipeline, but it only checks one stage of the fire pump's normal operating conditions. Fire pumps can be directly started or indirectly started; higher-power pumps require indirect starting. Indirect starting methods include Y/△ reduced-voltage starting, autotransformer reduced-voltage starting, and soft starter starting. In fire pump operation, soft starter starting is only an early stage of fire pump operation, followed by normal operation. The variable frequency method also fails to operate at the power frequency stage. However, the low-speed self-inspection method still plays a role in preventing fire pump rust. Relatively speaking, it has the characteristics of low-frequency drive, low-speed rotation, and low-power equipment operation.
Comparison of Self-Inspection Methods
In fire pump self-inspection methods, both constant-speed and low-speed self-inspection methods play a certain role in fire pump maintenance. From a maintenance management perspective, both can be used in fire water supply systems. Relatively speaking, the constant-speed self-inspection method can reflect the actual operating conditions of the fire pump. From the perspective of fire pump failure causes, failures caused by long-term disuse are mainly due to problems with the pump unit shaft engagement. Incomplete motor start-up conditions are less common, so overemphasizing the operation of the complete fire pump operating conditions is not very meaningful. The constant-speed self-inspection method is suitable for situations where the fire pump draws water from the fire water pool; the pipeline layout should be reasonably considered in the design. There are some problems during operation, which can quickly cause overpressure, making it unsuitable for engineering applications. However, constant-speed and low-speed self-inspection methods each have their own characteristics. Although the low-speed self-inspection method does not comprehensively detect the fire pump's operating conditions, it has no special requirements for the design of the fire pump pipeline and basically meets the technical requirements for fire pump self-inspection. It is more suitable for situations where the fire pump draws water directly from the municipal water network.