1. Introduction
This manual describes the assembly, installation, operation, and troubleshooting of the PowMr POW-LVM4K-24V Hybrid Solar Inverter. Please read this manual carefully before installation and operation for future reference.
The PowMr POW-LVM4K-24V is a multi-function inverter/charger, combining the functions of an inverter, MPPT solar charger, and battery charger to provide uninterruptible power support. It features a comprehensive large LCD display and user-configurable touch button operation for settings such as battery charging current, AC/solar charger priority, and acceptable input voltage.
Key Features:
- Off-grid solar inverter with pure sine wave output.
- Adjustable AC voltage (110VAC/120VAC) in Battery Mode.
- Utility power, battery, and PV power complement each other.
- Unique glass top cover design with 6.25-inch LCD display and touchable buttons.
- Built-in 140A MPPT solar charger (Max PV 5600W).
- High PV input range from 55V to 350Vdc.
- Smart battery charger design for optimized battery performance.
- Configurable AC/Battery input priority via LCD setting.
- Auto restart while PV is recovering.
- Over-load, over temperature, and output short circuit protection.
- Cold restart function.
- Built-in lithium battery automatic activation.
- Communication with RS232/RS485.
- Optional WiFi monitoring function.
- Optional anti-dust kit for harsh environments.
- Restore default settings with one click.
Figure 1: PowMr POW-LVM4K-24V Hybrid Solar Inverter with key specifications.
2. Safety Instructions
WARNING: This chapter contains important safety and operating instructions. Read and keep this manual for future reference.
- Before using the unit, read all instructions and cautionary markings on the unit, the batteries, and all appropriate sections of this manual.
- CAUTION – To reduce the risk of injury, charge only deep-cycle lead-acid type rechargeable batteries. Other types of batteries may burst, causing personal injury and damage.
- Do not disassemble the unit. Take it to a qualified service center when service or repair is required. Incorrect re-assembly may result in a risk of electric shock or fire.
- To reduce the risk of electric shock, disconnect all wirings before attempting any maintenance or cleaning. Turning off the unit will not reduce this risk.
- CAUTION – Only qualified personnel can install this device with a battery.
- NEVER charge a frozen battery.
- For optimum operation, select appropriate cable sizes as per required specifications.
- Be very cautious when working with metal tools on or around batteries. A potential risk exists to drop a tool to spark or short circuit batteries or other electrical parts, which could cause an explosion.
- Strictly follow the installation procedure when disconnecting AC or DC terminals. Refer to the INSTALLATION section for details.
- GROUNDING INSTRUCTIONS – This inverter/charger should be connected to a permanent grounded wiring system. Comply with local requirements and regulations.
- NEVER cause AC output and DC input short circuits. Do NOT connect to the mains when DC input short circuits.
- Warning!! Only qualified service persons are able to service this device. If errors still persist after following the troubleshooting table, send this inverter/charger back to a local dealer or service center for maintenance.
3. Product Overview
The inverter features an intuitive front panel with an LCD display, status indicators, and touch buttons for easy operation and monitoring.
Figure 2: Front and side view of the inverter with labeled components.
- LCD display
- Status indicator
- Charging indicator
- Fault indicator
- Function touch buttons (ESC, UP, DOWN, ENTER)
- Power on/off switch
- AC input
- AC output
- PV input
- Battery input
- RS485/RS232 communication port
4. Installation (Setup)
4.1 Unpacking and Inspection
Before installation, inspect the unit. Ensure that nothing inside the package is damaged. The package should contain the inverter unit and this user manual.4.2 Preparation
Before connecting any wirings, remove the bottom cover by unscrewing the two screws.4.3 Mounting the Unit
Consider the following points for selecting the installation location:
- Do not mount the inverter on flammable construction materials.
- Mount on a solid surface.
- Install the inverter at eye level for easy LCD display readability.
- The ambient temperature should be between 0°C and 55°C for optimal operation.
- Adhere to vertical installation position.
- Ensure sufficient heat dissipation and space for wiring by keeping other objects and surfaces at least 20cm from the sides and 50cm from the top/bottom.
WARNING: Suitable for mounting on concrete or other non-combustible surfaces only.
Figure 3: Recommended mounting clearances for the inverter.
4.4 Battery Connection
CAUTION: For safety and compliance, install a separate DC over-current protector or disconnect device between the battery and inverter. It is crucial to use appropriate cable and terminal sizes.
WARNING: All wiring must be performed by qualified personnel.
Recommended battery cable and terminal size:
| Model | Typical Amperage | Battery Capacity | Wire Size | Cable mm² | Torque Value |
|---|---|---|---|---|---|
| 3.0KW 24V | 110A | 100AH/200AH | 1*4AWG | 22 | 2~3 Nm |
| 4.0KW 24V | 150A | 200AH | 1*2AWG | 35 | 2~3 Nm |
Steps for Battery Connection:
- Assemble battery ring terminals based on recommended cable and terminal sizes.
- Connect all battery packs as required.
- Insert the ring terminal of the battery cable flatly into the inverter's battery connector. Tighten bolts with a torque of 2-3 Nm. Ensure correct polarity (+ to + and - to -) at both the battery and inverter/charger.
WARNING: Shock Hazard. Installation must be performed with care due to high battery voltage in series.
CAUTION: Do not place anything between the flat part of the inverter terminal and the ring terminal. Otherwise, overheating may occur.
CAUTION: Do not apply anti-oxidant substance on the terminals before they are connected tightly.
CAUTION: Before making the final DC connection or closing the DC breaker/disconnector, ensure positive (+) is connected to positive (+) and negative (-) to negative (-).
Figure 4: Proper battery terminal connection to the inverter.
4.5 AC Input/Output Connection
CAUTION: Before connecting to the AC input power source, install a separate AC breaker between the inverter and the AC input source. This ensures secure disconnection and over-current protection. Recommended AC breaker specs: 32A for 3.0KW, 40A for 4.0KW.
CAUTION: There are two terminal blocks labeled “INPUT” and “OUTPUT”. Do NOT mis-connect input and output connectors.
WARNING: All wiring must be performed by qualified personnel. Use appropriate cable sizes for AC input connection.
Suggested cable requirement for AC wires:
| Model | Gauge | Torque Value |
|---|---|---|
| 3.0KW | 10 AWG | 1.2~1.6 Nm |
| 4.0KW | 8 AWG | 1.4~1.6 Nm |
Steps for AC Input/Output Connection:
- Before making AC input/output connections, ensure the DC protector or disconnector is open.
- Remove 10mm of insulation from the six conductors. Shorten phase L and neutral conductor N by 3mm.
- Insert AC input wires according to the polarities indicated on the terminal block and tighten the terminal screws.
- Insert AC output wires according to the polarities indicated on the terminal block and tighten the terminal screws. Be sure to connect the PE protective conductor (ground) first.
- Ensure all wires are securely connected.
WARNING: Be sure that the AC power source is disconnected before attempting to hardwire it to the unit.
Figure 5: AC input and output terminal connections.
4.6 PV Connection
CAUTION: Before connecting to PV modules, install a separate DC circuit breaker between the inverter and PV modules.
WARNING: All wiring must be performed by qualified personnel. Use appropriate cable sizes for PV module connection.
Suggested cable requirement for PV wires:
| Model | Wire Size | Cable (mm²) | Torque Value (max) |
|---|---|---|---|
| 3.0KW/4.0KW | 1 x 12AWG | 4 | 1.2 Nm |
PV Module Selection:
- Open circuit Voltage (Voc) of PV modules must not exceed the max. PV array open circuit voltage of the inverter.
- Open circuit Voltage (Voc) of PV modules should be higher than the min. PV Array MPPT Voltage range.
| INVERTER MODEL | 3.0KW | 4.0KW |
|---|---|---|
| Max. PV Array Open Circuit Voltage | 350Vdc | |
| PV Array MPPT Voltage Range | 55Vdc~350Vdc | |
Steps for PV Module Connection:
- Remove 10mm of insulation from positive and negative conductors.
- Check correct polarity of connection cable from PV modules and PV input connectors. Connect positive (+) to positive (+) and negative (-) to negative (-).
- Ensure the wires are securely connected.
Figure 6: PV input terminal connections.
4.7 Final Assembly
After connecting all wirings, replace the bottom cover by screwing the two screws back in place.
5. Operation
5.1 Power ON/OFF
Once the unit is properly installed and batteries are connected, simply press the On/Off switch (located on the bottom of the case) to turn on the unit.5.2 Operation and Display Panel
The front panel includes three indicators, four function keys, and an LCD display to show operating status and input/output power information.
Figure 7: LCD display and function buttons.
LED Indicator:
| LED Indicator | Color | Messages |
|---|---|---|
| AC INV | Green | Solid On: Output is powered by utility in Line mode. Flashing: Output is powered by battery or PV in battery mode. |
| CHG | Green | Solid On: Battery is fully charged. Flashing: Battery is charging. |
| FAULT | Red | Solid On: Fault occurs in the inverter. Flashing: Warning condition occurs in the inverter. |
Function Keys:
| Function Key | Description |
|---|---|
| ESC | To exit setting mode |
| UP | To go to previous selection |
| DOWN | To go to next selection |
| ENTER | To confirm the selection in setting mode or enter setting mode |
LCD Display Icons:
The LCD displays various information including input source, configuration programs, fault information, output information, and battery information. Refer to the manual for a detailed breakdown of each icon and its meaning.5.3 LCD Setting
After pressing and holding the ENTER button for 3 seconds, the unit will enter setting mode. Use the “UP” or “DOWN” buttons to select setting programs, then press “ENTER” to confirm or “ESC” to exit. Detailed settings for output source priority, maximum charging current, battery type, auto restart functions, output voltage, output frequency, and battery equalization are available.
5.4 Operating Mode Description
The inverter supports various operating modes, including Line Mode, Battery Mode, and Standby/Power Saving Mode, each with specific behaviors for power supply and charging. The LCD display will indicate the current operating mode.
Figure 8: Multiple charging and output modes supported by the inverter.
Figure 9: Inverter compatibility with various battery types.
6. Maintenance
6.1 Battery Equalization
The equalization function helps reverse the buildup of negative chemical effects like stratification and removes sulfate crystals from battery plates, extending battery life. This function can be enabled via LCD setting program 33, by setting an equalization interval in program 37, or by activating it immediately in program 39.
6.2 Smart Design and Protection
The inverter features a smart design for excellent heat dissipation and dust prevention. It includes three cooling fans to increase effectiveness and dissipate heat, ensuring safer and more efficient operation. A dust-proof cover prevents dust from entering the inverter, extending its service life in harsh environments.
The system provides comprehensive protection against over temperature, over voltage, PV over voltage, short circuit, discharge, and over charge, ensuring the safety and stability of the entire system.
Figure 10: Smart design for heat dissipation and dust prevention, alongside full protection features.
7. Troubleshooting
This section provides guidance on common issues and their solutions. If errors persist after following these steps, please contact customer support.
7.1 Fault Reference Code
The LCD display will show specific fault codes to indicate issues. Refer to the table below for explanations and recommended actions.
| Fault Code | Fault Event |
|---|---|
| 01 | Fan is locked when inverter is off. |
| 02 | Over temperature |
| 03 | Battery voltage is too high |
| 04 | Battery voltage is too low |
| 05 | Output short circuited or over temperature is detected by internal converter components. |
| 06 | Output voltage is too high. |
| 07 | Overload time out |
| 08 | Bus voltage is too high |
| 09 | Bus soft start failed |
| 11 | Main relay failed |
| 51 | Over current or surge |
| 52 | Bus voltage is too low |
| 53 | Inverter soft start failed |
| 55 | Over DC voltage in AC output |
| 56 | Battery connection is open |
| 57 | Current sensor failed |
| 58 | Output voltage is too low |
7.2 Warning Indicator
The inverter provides warning codes for various conditions. Refer to the table below for details.
| Warning Code | Warning Event | Audible Alarm |
|---|---|---|
| 01 | Fan is locked when inverter is on. | Beep twice every second |
| 03 | Battery is over-charged | Beep twice every second |
| 04 | Low battery | Beep twice every second |
| 07 | Overload | Beep twice every second |
| 10 | Output power derating | Beep twice every second |
| 12 | Solar charger stops due to low battery. | |
| 13 | Solar charger stops due to high PV voltage. | |
| 14 | Solar charger stops due to overload. | |
| 15 | PV is weak | |
| 61 | When the battery communication is abnormal, stop charging and discharging. |
7.3 Troubleshooting Table
For detailed troubleshooting steps for various problems like unit shutdown, no response, or unit working in battery mode when mains exist, please refer to the comprehensive troubleshooting table in the full PDF manual.
8. Specifications
Below are detailed specifications for the PowMr POW-LVM4K-24V Hybrid Solar Inverter.
8.1 General Specifications
| Attribute | Value |
|---|---|
| Model Number | POW-LVM4K-24V |
| Rated Output Power | 4KVA/4KW |
| Battery Voltage | 24VDC |
| Battery Type | Lead-acid battery and lithium battery |
| Nominal Input Voltage | 120VAC |
| Nominal Input Frequency | 50Hz / 60Hz (Auto detection) |
| Efficiency | >95% (Rated R load, battery full charged) |
| Output Voltage Waveform | Pure Sine Wave |
| Floating Charging Voltage | 27VDC |
| Charging Algorithm | 3-Step |
| Max. PV Array Power | 5600W |
| Max. PV Current | 13A |
| Nominal PV Voltage | 350VDC |
| Start-up Voltage | 55VDC ± 10VDC |
| PV Array MPPT Voltage Range | 55VDC~350VDC |
| Max. PV Array Open Circuit Voltage | 350VDC |
| Max Charging Current | 140Amp |
| Safety Certification | CE |
| Operating Temperature Range | 0℃ to 55℃ |
| Storage temperature | -15℃~ 60℃ |
| Humidity | 5% to 95% Relative Humidity (Non-condensing) |
| Dimension (D*W*H) | 400x250x89 mm |
| Net Weight | 7.85KG |
8.2 Line Mode Specifications
| Parameter | 3.0KW/24V | 4.0KW/24V |
|---|---|---|
| Input Voltage Waveform | Sinusoidal (utility or generator) | |
| Nominal Input Voltage | 120Vac | |
| Low Loss Voltage | 95Vac±5V(UPS); 65Vac±7V(Appliances) | |
| Low Loss Return Voltage | 100Vac±5V(UPS); 70Vac±5V(Appliances) | |
| High Loss Voltage | 140Vac±5V | |
| High Loss Return Voltage | 135Vac±5V | |
| Max AC Input Voltage | 150Vac | |
| Nominal Input Frequency | 50Hz / 60Hz (It can be set in program 09) | |
| Low Loss Frequency | 45±1Hz/55±1Hz | |
| Low Loss Return Frequency | 47±1Hz/57±1Hz | |
| High Loss Frequency | 55±1Hz/65±1Hz | |
| High Loss Return Frequency | 53±1Hz/63±1Hz | |
| Output Short Circuit Protection | Line mode: Circuit Breaker; Battery mode: Electronic Circuits | |
| Efficiency (Line Mode) | >95% (Rated R load, battery full charged) | |
| Transfer Time | 10ms typical (UPS); 20ms typical (Appliances) | |
8.3 Inverter Mode Specifications
| Parameter | 3.0KW/24V | 4.0KW/24V |
|---|---|---|
| Rated Output Power | 3.0KW | 4.0KW |
| Output Voltage Waveform | Pure Sine Wave | |
| Output Voltage Regulation | 120Vac±5% | |
| Output Frequency | 60Hz or 50Hz | |
| Peak Efficiency | 94% | |
| Overload Protection | 5s@≥150% load; 10s@110%~150% load | |
| Surge Capacity | 2* rated power for 5 seconds | |
| Nominal DC Input Voltage | 24Vdc | |
| Cold Start Voltage | 23.0Vdc | |
| Low DC Warning Voltage | 22.0Vdc | |
| Low DC Warning Return Voltage | 23.0Vdc | |
| Low DC Cut-off Voltage | 21.0Vdc | |
| High DC Recovery Voltage | 29Vdc | |
| High DC Cut-off Voltage | 31Vdc | |
| No Load Power Consumption | <35W | |
8.4 Charge Mode Specifications
| Parameter | 3.0KW/24V | 4.0KW/24V |
|---|---|---|
| Utility Charging Mode | ||
| Charging Current (UPS) @ Nominal Input Voltage | 80A | 110A |
| Bulk Charging Voltage (Flooded Battery) | 29.2Vdc | |
| Bulk Charging Voltage (AGM / Gel Battery) | 28.2Vdc | |
| Floating Charging Voltage | 27Vdc | |
| Charging Algorithm | 3-Step | |
| Solar Charging Mode | ||
| Rated Power | 5600W | |
| PV Charge Current | 100A | 140A |
| Efficiency | 98.0% max. | |
| Max. PV Array Open Circuit Voltage | 350Vdc | |
| PV Array MPPT Voltage Range | 55-350Vdc | |
| Standby Power Consumption | 2W | |
| Battery Voltage Accuracy | +/-0.3% | |
| PV Voltage Accuracy | +/-2V | |
| Charging Algorithm | 3-Step | |
9. User Tips
No specific user tips are available from the provided reviews or Q&A content.
10. Warranty and Support
The PowMr POW-LVM4K-24V Hybrid Solar Inverter comes with a 1-year warranty.
For technical support or service, please contact:
- Company: SHENZHEN HEHEJIN INDUSTRIAL CO.,LTD
- Tel/Fax: +86755-28219903
- Email: Support@powmr.com
- Web: www.powmr.com
- Address: Henggang Street, Longgang District, Shenzhen, Guangdong, China
For the complete user manual and detailed diagrams, please refer to the official PDF document: PowMr Solar Inverter Charger User Manual (PDF).
