1. Introduction
1.1 Purpose and Scope
This manual describes the assembly, installation, operation, and troubleshooting of the PowMr 4KW Hybrid Solar Inverter. Please read this manual carefully before installation and operation. Keep this manual for future reference. This document provides safety and installation guidelines, as well as information on tools and wiring.
1.2 Key Features
- Off-grid solar inverter functionality.
- Adjustable AC voltage (100VAC, 110VAC, 120VAC) in Battery Mode.
- Utility power, battery, and PV power complement each other.
- Pure sine wave output.
- 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: 55-350Vdc.
- Smart battery charger design for optimized battery performance.
- Configurable AC/Battery input priority via LCD setting.
- Auto-restart function when PV is recovering.
- Overload, over-temperature, and output short-circuit protection.
- Cold restart function.
- Built-in lithium battery automatic activation.
- Communication via RS232/RS485.
- Optional WiFi monitoring function.
- Optional anti-dust kit for harsh environments.
- One-click restore to default settings.
1.3 Basic System Architecture
The inverter/charger can be integrated into a system including a generator or utility power source and optional PV modules. It is suitable for powering various appliances in home or office environments, such as lamps, fans, refrigerators, and air conditioners.
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 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 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 battery.
- NEVER charge a frozen battery.
- For optimum operation of this inverter/charger, please follow required specifications to select appropriate cable size. It's very important to correctly operate this inverter/charger.
- 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 and could cause an explosion.
- Please strictly follow installation procedure when you want to disconnect AC or DC terminals. Please refer to the INSTALLATION section of this manual for details.
- GROUNDING INSTRUCTIONS: This inverter/charger should be connected to a permanent grounded wiring system. Be sure to comply with local requirements and regulations to install this inverter.
- NEVER cause AC output and DC input short-circuited. 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 troubleshooting table, please send this inverter/charger back to local dealer or service center for maintenance.
3. Setup (Installation)
3.1 Unpacking and Inspection
Before installation, inspect the unit to ensure nothing inside the package is damaged. You should have received the unit and a user manual.
3.2 Preparation
Before connecting any wirings, remove the bottom cover by unscrewing two screws.
3.3 Mounting the Unit
Consider the following points when selecting a mounting 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 wall mounting.
- Ensure sufficient space (20cm on sides, 50cm top/bottom) for heat dissipation and wire removal.
CAUTION: Suitable for mounting on concrete or other non-combustible surfaces only.
3.4 Battery Connection
CAUTION: For safety and compliance, install a separate DC over-current protector or disconnect device between the battery and inverter. Refer to the table below for recommended fuse/breaker sizes.
WARNING: All wiring must be performed by qualified personnel. Use appropriate cable and terminal sizes for system safety and efficient operation.
| 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 units require.
- NOTE: Only use sealed lead-acid (GEL/AGM) or lithium batteries.
- Insert the ring terminal of the battery cable flatly into the inverter's battery connector. Ensure bolts are tightened to 2-3 Nm. Verify correct polarity (+ to + and - to -) at both the battery and inverter.
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 to prevent overheating. Do not apply anti-oxidant substance on terminals before connecting. Before final DC connection, ensure correct polarity.
3.5 AC Input/Output Connection
CAUTION: Before connecting to AC input power, install a separate AC breaker between the inverter and the AC input source. Recommended breaker specs: 32A for 3.0KW, 40A for 4.0KW. Do NOT mis-connect input and output connectors.
WARNING: All wiring must be performed by qualified personnel. Use appropriate cable for AC input connection.
| 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 connections, ensure the DC protector or disconnector is open.
- Remove 10mm insulation from six conductors. Shorten phase L and neutral conductor N by 3mm.
- Insert AC input wires according to indicated polarities (L→LINE (brown or black), N→Neutral (blue or white)) on the terminal block and tighten screws.
- Insert AC output wires according to indicated polarities. Connect PE protective conductor (Ground (green)) first.
- Ensure all wires are securely connected.
CAUTION: Important! Connect AC wires with correct polarity. Incorrect connection can cause utility short-circuits in parallel operation. For appliances like air conditioners, ensure they have a time-delay function to prevent damage from short power outages.
3.6 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 for PV module connection.
| 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 (350Vdc).
- Open circuit Voltage (Voc) of PV modules should be higher than the min. PV Array MPPT Voltage range (55Vdc).
Steps for PV Module Connection:
- Remove 10mm insulation from positive and negative conductors.
- Check correct polarity of connection cable from PV modules and PV input connectors. Connect positive pole (+) to positive pole (+) and negative pole (-) to negative pole (-).
- Ensure all wires are securely connected.
3.7 Lithium Battery Connection (if applicable)
If the inverter is matched with lithium batteries, only those with compatible BMS communication protocols are allowed. You need to set the battery type to "Lib-485" in Program 5.
Steps for Lithium Battery Connection:
- Assemble battery ring terminals based on recommended cable and terminal specifications.
- Insert the ring terminal of the battery cable flatly into the inverter's battery connector. Ensure bolts are tightened to 2-3 Nm. Verify correct polarity.
- Connect the RJ45 connector to the COMM port on the inverter.
- Connect the other end of the RJ45 plug to the battery communication port (RS485). Ensure RS485-A connects to RS485-A and RS485-B connects to RS485-B.
The inverter BMS interface pin definition is as follows:
| Pin Number | Definition |
|---|---|
| 1 | RX |
| 2 | TX |
| 3 | VCC |
| 4 | VCC |
| 5 | RS485-A |
| 6 | RS485-B |
| 7 | GND |
| 8 | GND |
3.8 Final Assembly
After connecting all wirings, replace the bottom cover by screwing the two screws back in place.
4. Operating Instructions
4.1 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.
4.2 Operation and Display Panel
The operation and display panel is on the front of the inverter, featuring three indicators, four function keys, and an LCD display for operating status and input/output power information.
LED Indicators:
| LED Indicator | Color | State | Message |
|---|---|---|---|
| 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 |
4.3 LCD Display Icons and Information
The LCD displays various information including input source, configuration, fault details, output information, and battery status. Icons represent AC input, PV input, input voltage/frequency, PV voltage, battery voltage, charger current, output voltage/frequency, load percentage, and battery level.
The display also shows warning and fault codes, with specific icons for each. For example, a flashing error code indicates a warning, while a solid error code indicates a fault.
4.4 LCD Setting
To enter setting mode, press and hold the ENTER button for 3 seconds. Use UP/DOWN to select programs and ENTER to confirm, or ESC to exit. Key settings include:
- Program 00: Exit setting mode.
- Program 01: Output source priority (Solar first, SBU priority, SUB priority).
- Program 02: Maximum charging current (utility + solar).
- Program 03: AC input voltage range (Appliances, UPS).
- Program 04: Power saving mode enable/disable.
- Program 05: Battery type (AGM, Flooded, Lithium, User-Defined, Lithium with communication).
- Program 06: Auto restart when overload occurs.
- Program 07: Auto restart when over temperature occurs.
- Program 08: Output voltage (100V, 110V, 120V).
- Program 09: Output frequency (50Hz, 60Hz).
- Program 11: Maximum utility charging current.
- Programs 12, 13: Setting voltage points for utility/battery source return (SBU priority).
- Programs 26, 27: Bulk and Floating charging voltage.
- Program 29: Low DC cut-off voltage.
- Program 30: Restore default settings.
- Programs 33-39: Battery equalization settings (enable/disable, voltage, time, interval).
4.5 Operating Mode Description
The inverter operates in various modes:
- Standby/Power Saving Mode: No output, but can charge batteries. In power saving mode, output is off if connected load is very low.
- Line Mode: Unit provides output power from mains and charges battery. If SBU priority is selected, solar and utility power can provide loads and charge battery.
- Battery Mode: Unit provides output power from battery and PV power. PV energy can also supply loads and charge battery simultaneously.
- Fault Mode: Inverter disconnects all inputs and outputs due to internal circuit errors or external reasons (e.g., over temperature, output short circuit). Red fault indicator is steady on, and buzzer alarms.
5. Maintenance
Regular maintenance ensures the longevity and optimal performance of your PowMr Hybrid Solar Inverter. While specific detailed maintenance schedules are provided in the full user manual (PDF), general practices include:
- Keeping the unit free from dust and debris, especially around cooling fans and vents. The optional anti-dust kit can help in harsh environments.
- Periodically checking all wiring connections for tightness and signs of wear or corrosion.
- Monitoring the LCD display for any warning or fault indicators and addressing them promptly.
- Ensuring proper ambient temperature to prevent overheating.
For detailed maintenance procedures, including battery equalization schedules and component checks, please refer to the comprehensive user manual PDF available at: PowMr Hybrid Solar Inverter User Manual (PDF).
6. Troubleshooting
This section provides a guide to common problems, their possible causes, and corrective actions.
6.1 Warning Indicators
The inverter displays warning codes for various conditions:
| 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. |
6.2 Fault Reference Codes
The inverter displays fault codes for critical issues:
| 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 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. |
6.3 General Troubleshooting Table
| Problem | LCD/LED/Buzzer | Explanation / Possible Cause | What to do |
|---|---|---|---|
| Unit shuts down automatically during startup process. | LCD/LEDs and buzzer active for 3 seconds, then off. | Battery voltage too low (<1.91V/Cell). | 1. Re-charge battery. 2. Replace battery. |
| No response after power on. | No indication. | 1. Battery voltage too low (<1.4V/Cell). 2. Battery polarity reversed. | 1. Check battery connections. 2. Re-charge battery. 3. Replace battery. |
| Input voltage displayed as 0 on LCD, green LED flashing. | Input protector tripped. | Check if AC breaker is tripped and AC wiring is connected. | |
| Mains exist but unit works in battery mode. | Green LED flashing. | Insufficient quality of AC power (shore or generator). | 1. Check if AC wires are too thin/long. 2. Check generator/input voltage range setting. |
| Green LED flashing. | Set "Solar First" as output source priority. | Change output source priority to Utility first. | |
| When unit is turned on, internal relay switches on/off repeatedly. | LCD display and LEDs flashing. | Battery is disconnected. | Check if battery wires are connected. |
| Buzzer beeps continuously and red LED is on. | Fault code 07 | Overload error. Inverter overloaded 110% and time is up. | Reduce connected load. |
| Fault code 05 | Output short-circuited. | Check wiring, remove abnormal load. | |
| Fault code 02 | Internal temperature of inverter component over 100°C. | Check air flow, ambient temperature. | |
| Fault code 03 | Battery is over-charged. | Return to repair center. | |
| Fault code 01 | Fan fault. | Replace the fan. | |
| Fault code 06/58 | Output abnormal (Inverter voltage below 190Vac or higher than 260Vac). | 1. Reduce connected load. 2. Return to repair center. | |
| Fault code 08/09/53/57 | Internal components failed. | Return to repair center. | |
| Fault code 51 | Over current or surge. | Restart unit, if error persists, return to repair center. | |
| Fault code 56 | Battery is not connected well or fuse is burnt. | If battery is connected, return to repair center. |
7. Specifications
7.1 Line Mode Specifications
| Parameter | 3.0KW/24V | 4.0KW/24V |
|---|---|---|
| Input Voltage Waveform | Sinusoidal (utility or generator) | |
| Nominal Input Voltage | 120Vac | |
| Max AC Input Voltage | 150Vac | |
| Nominal Input Frequency | 50Hz / 60Hz (set in program 09) | |
| 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) | |
7.2 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% | |
| Surge Capacity | 2* rated power for 5 seconds | |
| Nominal DC Input Voltage | 24Vdc | |
| Cold Start Voltage | 23.0Vdc | |
| Low DC Cut-off Voltage | 21.0Vdc | |
| High DC Cut-off Voltage | 31Vdc | |
| No Load Power Consumption | <35W | |
7.3 Charge Mode Specifications
| Parameter | 3.0KW/24V | 4.0KW/24V |
|---|---|---|
| Utility Charging Mode | ||
| Charging Current (UPS) @ Nominal Input Voltage | 80A | 110A |
| 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 | |
| Charging Algorithm | 3-Step | |
7.4 General Specifications
| Parameter | 3.0KW/24V | 4.0KW/24V |
|---|---|---|
| Safety Certification | CE | |
| Operating Temperature Range | 0°C to 55°C | |
| Storage temperature | -15°C~60°C | |
| Dimension (D*W*H), mm | 400*250*89mm | |
| Net Weight, kg | 7.5kg | 8.5kg |
7.5 Approximate Back-up Time Table (4.0KW Model)
| Load (W) | Backup Time @ 24Vdc 100Ah (min) | Backup Time @ 24Vdc 200Ah (min) |
|---|---|---|
| 300 | 449 | 1100 |
| 600 | 222 | 525 |
| 900 | 124 | 303 |
| 1200 | 95 | 227 |
| 1500 | 68 | 164 |
| 1800 | 56 | 126 |
| 2100 | 48 | 108 |
| 2400 | 35 | 94 |
| 2700 | 31 | 74 |
| 3200 | 28 | 67 |
Note: Backup time depends on the quality, age, and type of battery. Specifications of batteries may vary depending on different manufacturers.
* Product technical specifications are subject to change without notice.
8. Warranty & Support
The PowMr Hybrid Solar Inverter comes with a 1-year warranty. For technical support, service, or maintenance, please contact PowMr Official Store directly. If errors persist after following the troubleshooting guide, return the inverter/charger to your local dealer or service center.
Contact Information:
SHENZHEN HEHEJIN INDUSTRIAL CO.,LTDTel/Fax: +86755-28219903
Email: Support@powmr.com
Web: www.powmr.com
Address: Henggang Street, Longgang District, Shenzhen, Guangdong, China
For the most comprehensive information, including detailed wiring diagrams and advanced settings, please refer to the official user manual PDF: PowMr Hybrid Solar Inverter User Manual (PDF).
9. User Tips
- WiFi Monitoring: If your inverter includes the optional WiFi monitoring function, ensure you download the official PowMr app and follow the in-app instructions for setup. This allows for remote monitoring of your system's performance.
- Battery Compatibility: When connecting lithium batteries, always ensure they are compatible with the inverter's BMS communication protocol. If communication fails, the inverter may cut off output. If the communication protocol does not match, you can select "LIB" mode in the settings.
- Cable Sizing: Always use the recommended cable sizes for battery, AC input/output, and PV connections to ensure safety and optimal performance. Undersized cables can lead to efficiency losses and safety hazards.
- Environmental Protection: Consider using the optional anti-dust kit if installing the inverter in a harsh or dusty environment to extend its service life.
