Month: June 2025

Introduction

Inverters are vital components in industrial automation, enabling precise control over motor speed and torque across various sectors, including manufacturing and energy. The Shihlin SS2 series inverter, manufactured by Shihlin Electric, is widely recognized for its reliability and performance. However, like any complex equipment, it may encounter faults during operation. One such issue is the E0 fault, which can be perplexing for users due to its specific triggering conditions. This article provides a comprehensive analysis of the E0 fault in the Shihlin SS2 inverter, detailing its meaning, causes, solutions, and preventive measures to assist users in restoring normal operation efficiently.

1. Meaning of the E0 Fault

According to the Shihlin SS2 Series Inverter Manual (version V1.07), the E0 fault is triggered under specific conditions related to the inverter’s parameter settings and operation mode. Specifically, when parameter P.75 (stop function setting) is set to 1, and the inverter is operating in a mode other than PU (panel operation mode) or H2 (high-frequency mode), pressing the stop button (labeled as “(20) key” in the manual) for 1.0 second causes the inverter to stop. The display shows “E0,” and all functions are disabled or reset. This behavior acts as a protective mechanism to prevent unintended operation or potential damage under these conditions.

Interestingly, the manual also lists E0 in the fault code table under “00(H00)” as “no fault” (无异常), which may indicate a different context, such as a default or reset state in fault logging. This dual reference suggests that E0’s meaning depends on the operational context, but the primary focus here is its association with the stop function and parameter P.75.

2. Causes of the E0 Fault

To effectively resolve the E0 fault, understanding its causes is essential. Based on the manual and related information, the following are the primary reasons for the E0 fault:

• Parameter P.75 Configuration: Parameter P.75 governs the inverter’s stop behavior. When set to 1, it enables a deceleration stop function. In non-PU or non-H2 modes, pressing the stop button for 1 second triggers the E0 fault, as the inverter interprets this as an invalid operation under the current settings.
• Operation Mode Restrictions: The E0 fault is specific to non-PU and non-H2 modes. PU mode allows direct control via the inverter’s control panel, while H2 mode may relate to specific high-frequency applications. Operating in external control mode (e.g., via external signals) with P.75 set to 1 increases the likelihood of triggering E0.
• External STE/STR Command Interference: External start/stop commands (STE/STR) can conflict with the inverter’s settings. The manual notes that when E0 occurs, these external commands are canceled, suggesting that signal interference may contribute to the fault.
• Operator Error: Inadvertently pressing the stop button for more than 1 second in an incompatible mode can trigger the E0 fault. This is particularly common during initial setup, debugging, or when operators are unfamiliar with the inverter’s operation.

It’s worth noting that earlier versions of the Shihlin SS2 manual (e.g., V1.01) describe E0 as a communication error related to parity check issues. This discrepancy indicates that fault code definitions may have evolved across manual versions, with V1.07 providing the most relevant information for modern SS2 inverters.

3. Solutions for the E0 Fault

Resolving the E0 fault involves a systematic approach to eliminate its triggers and restore normal operation. The following steps, derived from the manual (version V1.07), are recommended:

1. Cancel External STE/STR Commands:
   • Inspect the inverter for any external start/stop (STE/STR) signals that may be interfering with its operation.
   • Cancel these inputs to ensure no external commands conflict with the inverter’s settings. In program operation mode, manual signals typically do not require clearing, but verifying the absence of interference is critical.
2. Reset the Inverter:
   • Locate the stop button (labeled “(20) key”) on the control panel.
   • Press and hold it for at least 1.0 second to clear the E0 fault and reset the inverter to an operational state. This is a direct method recommended in the manual.
3. Check and Adjust Parameter P.75:
   • Access the inverter’s parameter setting menu to review the value of P.75.
   • If P.75 is set to 1 and this is not suitable for your application, change it to 0 (the factory default) or another appropriate value. Refer to section 5.33 of the manual for detailed guidance on adjusting P.75.
4. Verify Operation Mode:
   • Ensure the inverter is operating in the correct mode (PU or H2, if required for your application).
   • Switch to the appropriate mode to prevent the fault from recurring.
5. Perform a Parameter Reset:
   • If the above steps do not resolve the issue, use parameters P.996 or P.997 to reset the inverter. These parameters can clear fault records or restore factory settings, as outlined in sections 5.78 and 5.80 of the manual.
6. Seek Professional Assistance:
   • Persistent faults may indicate hardware issues (e.g., faulty motherboard or wiring errors) or complex configuration problems.
   • Contact Shihlin Electric’s technical support team via their official website or arrange for the inverter to be inspected by the manufacturer.

The following table summarizes the causes and solutions for the E0 fault:

Possible Cause	Solution
P.75 set to 1, non-PU/H2 mode operation	Adjust P.75 to 0 or other values (manual section 5.33)
Stop button pressed for 1.0 second	Press stop button for 1.0 second to reset
External STE/STR command interference	Cancel external commands, check wiring
Hardware or configuration issues	Reset using P.996/P.997 or contact manufacturer

4. Preventive Measures for E0 Fault

To minimize the occurrence of E0 faults and ensure reliable inverter operation, consider the following preventive measures:

• Proper Parameter Configuration:
  • During installation and commissioning, thoroughly review the Shihlin SS2 Series Inverter Manual (version V1.07) to ensure parameters like P.75 are correctly set for your application.
  • Avoid modifying parameters without understanding their functions to prevent unintended faults.
• Regular Maintenance:
  • Conduct periodic inspections of the inverter’s wiring, cooling system, and control panel to check for loose connections, dust buildup, or overheating.
  • Regular maintenance reduces the risk of faults caused by environmental or mechanical issues.
• Operator Training:
  • Train all personnel operating the SS2 inverter on its proper use and fault-handling procedures.
  • Ensure the manual is readily available for quick reference during operation or troubleshooting.
• Power Supply Stability:
  • Use voltage stabilizers or surge protectors to protect the inverter from power fluctuations, which can contribute to faults.
  • A stable power supply is essential for long-term reliability.
• Fault Monitoring and Logging:
  • Maintain a record of all fault occurrences, including their conditions and resolutions.
  • Regularly monitor the inverter’s performance to identify and address potential issues early.

5. Conclusion

The E0 fault in the Shihlin SS2 inverter, while initially confusing, can be effectively managed by understanding its association with parameter P.75 and specific operation modes. By following the outlined steps—canceling external STE/STR commands, resetting the inverter, adjusting P.75, and verifying the operation mode—users can typically resolve the fault quickly. Additionally, adopting preventive measures such as proper parameter setup, regular maintenance, operator training, power protection, and fault monitoring can significantly reduce the likelihood of E0 faults. For persistent issues, contacting Shihlin Electric’s technical support or arranging professional inspection is advisable. By implementing these strategies, users can ensure the stable and efficient operation of their SS2 inverters, maximizing performance in industrial applications.

Key Citations

1. System Overview

Constant pressure water supply technology is widely used in modern industrial and civil water systems for efficient and energy-saving operation. This project uses the Milan M5000 inverter as the control core, combined with the YTZ-150 potentiometric remote pressure gauge, to construct a closed-loop constant pressure control system. It enables automatic adjustment of a single water pump to ensure the outlet pressure remains stable within the set range.

The system features low cost, easy maintenance, and fast response, making it suitable for small water supply systems, factory cooling water circulation, boiler water replenishment, and more.

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2. Main Hardware and Functional Modules

1. Inverter: Milan M5000 Series

• Built-in PID controller
• Supports multiple analog inputs (0-10V, 0-5V, 4-20mA)
• Provides +10V power output terminal for sensor power supply

2. Pressure Sensor: YTZ-150 Potentiometric Remote Pressure Gauge

• Resistive output with a range of approx. 3–400Ω
• Rated working voltage ≤6V, but 10VDC tested in practice with stable long-term operation
• Outputs a voltage signal (typically 0–5V) varying with pressure via a voltage divider principle

3. Control Objective

• Adjust pump speed using the inverter to maintain constant pipe pressure
• Increase frequency when pressure drops, and decrease when pressure exceeds the setpoint to save energy

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3. Wiring and Jumper Settings

1. 3-Wire Sensor Wiring (Tested with 10V)

Sensor Wire	Function	Inverter Terminal
Red	+10V supply	Connect to +10V
Green	Ground (GND)	Connect to GND
Yellow	Signal output	Connect to VC1 input

2. Analog Input Jumper JP8

• Default: 1–2 connected, indicating 0–10V input
• Keep the default setting in this project (no need to switch to 2–3)

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4. PID Parameter Settings (Based on Field Use)

Parameter	Description	Value	Note
P7.00	Enable closed-loop control	1	Enable PID control
P7.01	Setpoint source	0	Digital input from panel
P7.02	Feedback source	0	VC1 analog input (0–10V)
P7.05	Target pressure value (%)	30.0	Corresponds to 0.3MPa if P7.24=1.000
P7.07	Feedback gain	1.00	Linear scaling factor for feedback
P7.10	PID control structure	1	Proportional + integral control
P7.11	Proportional gain	0.50	Recommended initial value
P7.12	Integral time constant	10.0	In seconds
P7.24	Pressure sensor range (MPa)	1.000	1.000 MPa full-scale
P1.19	Maximum voltage input	5.00	Matched to 0–5V signal range

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5. Sleep Function Configuration

To enable energy saving when there is no pressure demand, the inverter can be configured to sleep:

Parameter	Description	Value	Note
P7.19	Wake-up threshold	0.001	Minimum pressure to resume operation (MPa)
P7.20	Sleep threshold	1.000	Enter sleep mode above this value (MPa)
P7.23	Constant pressure mode	1	One-pump control mode

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6. PID Tuning Guidelines

1. After starting the system, observe pressure fluctuations:
   • If large oscillations, reduce P7.11 (proportional gain)
   • If sluggish response, reduce P7.12 (integral time)
2. Aim to maintain output pressure within ±2% of the P7.05 set value
3. Ensure return pipes have damping to prevent sudden pressure spikes

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7. Key Considerations

1. Keep JP8 jumper at default 1–2 for 0–10V input
2. YTZ-150 sensor has been tested with 10V power supply and works stably
3. Ensure proper grounding (PE terminal) to avoid PID interference from common-mode noise
4. If feedback signal is noisy, add a filter capacitor (0.1–0.47μF) between VC1 and GND

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8. Conclusion

With this design, the Milan M5000 inverter combined with the YTZ-150 pressure sensor delivers a cost-effective and reliable constant pressure control solution for water systems. The inverter’s built-in PID control simplifies implementation compared to external PLCs and offers strong performance with minimal tuning. As long as power supply, signal matching, and grounding are properly managed, the system achieves excellent closed-loop control stability.