Hitachi hitachi low current trip function for pumping applications

L300P/SJ300 Low Current Trip Function for Pumping Applications

Sometimes it is desirable to have the inverter trip when running at constant speed and the motor current falls below a certain threshold level. In the case of a pump, this would be indicative of absence of fluid in the pump, and hence no load on the motor. This functionality could also be useful in other applications where it is important to know that there is no load on the motor.

L300P Setup

The inverter incorporates an intelligent output function called Overload Advance Notice [OL]. This is ordinarily used to detect motor current higher than a user selectable threshold set with parameter C041. This signal can be configured to be active during acceleration, deceleration, and constant speed, by setting parameter C040 set to 00. This means that whether the current is above or below threshold is monitored whenever the inverter is in RUN mode. The [OL] function is configured to one of the outputs by setting either C21 or C22 to a value of “03”.

There is another intelligent output function called Frequency Arrival – Type 1 [FA1]. This function turns on when the drive arrives at the set speed, and is off otherwise. This is configured to one of the outputs by setting either C021 or C022 to a value of “01”.

Further, there is an intelligent input function called External Trip [EXT]. This will take a signal from outside the inverter and when turned on, will trip the inverter, displaying the unique error code of E12.

We can utilize these three functions together to create an undercurrent trip at constant speed function. In this example, we will assume an L300P inverter. In our example, we will use input 5 for the External Trip [EXT] signal, output relay 11 for [FA1], and output relay 12 for [OL]. We will invert the logic of [OL] by setting C032 to “01”. This gives us [OL]. The Table 1 below shows the necessary parameter settings. The Wiring diagram on Page 5 shows the required signal connections. The Timing Chart on Page 3 shows the relationship of the input and output signals. A logical “AND” between [FA1] and [OL] is achieved by connecting the contacts in series.

Table 1

Parameter	C005	C015	C021	C022	C031	C032	C040	C041

								Desired
Value	12	00	01	03	00	01	00	Low Current
Value	12	00	01	03	00	01	00	Threshold
								Threshold
								Level (A)*

*Parameter C041 is programmed in Amperes, and can be set from 0.1 to 2.0 times rated current for each inverter model.

Hitachi America, Ltd.

Page 2

hitachi low current trip function for pumping applications specifications

Hitachi, a global leader in technology and innovation, has developed a highly efficient low current trip function specifically designed for pumping applications. This feature is pivotal for ensuring the reliability and longevity of pumping systems. In various industries, including water management, oil, and gas, maintaining optimal operational efficiency is crucial. The low current trip function plays a vital role in achieving this by preventing equipment damage due to electrical faults or overload conditions.

One of the main features of Hitachi's low current trip function is its ability to detect abnormal current levels in real-time. This allows for immediate action to be taken, ensuring that the pump equipment remains protected from potential damage. By monitoring the current levels and automatically tripping the circuit when thresholds are exceeded, the system helps to prevent overheating and premature wear of components. This proactive approach not only minimizes downtime but also reduces the overall maintenance costs associated with pump operations.

Technologically, Hitachi integrates advanced microprocessor-based control systems within their pumping solutions, enabling enhanced monitoring and feedback loops. These systems provide detailed insights into operational performance, allowing operators to make data-driven decisions. The low current trip function is part of a broader suite of protective features designed to enhance the operational efficiency and safety of pumping applications.

Additionally, the low current trip function is characterized by its adaptability to various pumping environments. It can be customized according to specific application requirements, ensuring optimal performance across different settings. This flexibility is essential for industries that may experience fluctuating operational conditions, requiring an adaptive response to changing demands.

Safety is another critical aspect of Hitachi’s low current trip function. By implementing stringent protective measures, operators can rest assured that their pumping systems are safeguarded against electrical anomalies. This focus on safety helps to foster a reliable operational environment, reducing the risk of catastrophic failures that could disrupt services.

In conclusion, Hitachi's low current trip function is a vital component in the performance and reliability of pumping applications. With its ability to monitor current levels, advanced microprocessor integration, adaptability, and emphasis on safety, it stands out as a significant technological advancement in the industry. As industries continue to evolve, such innovative features will be essential in sustaining productivity and reducing operational risks.

L300P Setup

Level (A)*

hitachi low current trip function for pumping applications specifications