PowMr POW-LVM3.5K-48V Solar Inverter Charger User Manual

Important Safety Information

Please retain this manual for future reference!

Before installation, please read all instructions and warnings in this manual carefully!

• Installation and wiring must comply with local and national electrical codes (NEC) and be performed by a certified technician.
• Do not disassemble or attempt to repair the inverter; there are no user-serviceable parts.
• Do not parallel this unit with other AC input power sources to avoid damage.
• Do not touch the unit while it is operating, as it will be very hot. Do not remove the terminal cover while the unit is operating.
• Ensure all connections to the inverter are secure. Sparks may occur during wiring, so ensure no flammable materials or gases are present in the installation area.
• It is recommended to install a circuit breaker or fuse externally.
• After installation, check all wiring connections to ensure they are secure and safe.
• Do not allow the positive (+) and negative (-) terminals of the battery to touch. Sealed lead-acid, flooded lead-acid, gel-sealed lead-acid, or maintenance-free sealed lead-acid batteries can be used.
• Explosive battery gas may be produced during charging. Ensure adequate ventilation to dissipate hazardous gases.
• Exercise caution when operating with large lead-acid battery banks. Wear safety goggles and have clean water ready to prevent contact with battery acid.
• Overcharging and excessive gas precipitation can damage battery plates, leading to shedding. Overcharging voltage or duration can cause damage. Refer to the specific requirements of the battery used in your system.

1. General Information

The POW series is a new hybrid solar inverter charger that integrates solar energy storage, battery storage, and AC sine wave output. With DSP control and advanced control algorithms, it offers high response speed, high reliability, and high industrial standards. It supports four charging modes: solar only, AC priority, solar priority, and hybrid AC/solar charging. It also offers two output modes: bypass and inverter output, ensuring uninterrupted power supply. The solar charger module utilizes the latest MPPT technology to rapidly track the maximum power point of the PV array under any condition, maximizing energy harvest from solar panels. The AC-DC charger module employs advanced control algorithms for full digital dual closed-loop control of voltage and current, resulting in a compact size and high control accuracy. With a wide AC voltage input range and comprehensive input/output protection, it provides stable and reliable battery charging and protection. The DC-AC inverter module is based on a fully digital intelligent design, utilizing advanced SPWM technology to output a pure sine wave, converting DC to AC for use with household appliances, power tools, industrial equipment, and electronic audio-visual equipment. The unit features a segmented LCD display to show system operating data and status. Comprehensive electronic protection ensures overall system safety and stability.

1.1. Key Features

• Full digital voltage and current dual closed-loop control with advanced sine pulse width modulation technology for pure sine wave output.
• Two output modes: AC bypass and inverter output for uninterrupted power supply.
• Four available charging modes: Solar only, AC priority, Solar priority, and Hybrid AC/Solar charging.
• Advanced Maximum Power Point Tracking (MPPT) technology with up to 99.9% efficiency.
• LCD display with 3 indicator lights to dynamically show system data and operating status.
• Manual ON/OFF switch for AC output control.
• ECO mode available to reduce energy loss.
• Smart variable speed fan for efficient heat dissipation, extending system life.
• Battery activation by PV solar or AC power; compatible with lead-acid and lithium batteries.
• Comprehensive protection functions including short circuit, over/under voltage, overload, and reverse polarity protection.

1.2. Battery Charging Modes

The solar inverter offers four operating modes that dictate how the battery bank is charged. These modes are Solar Priority, AC Priority, Hybrid Charging, and Solar Only Charging.

Solar Priority

In Solar Priority mode, daytime solar energy is fully utilized to charge the battery. This allows for off-grid operation during peak AC periods, reducing AC charging costs. The system will automatically switch to AC power as a backup only if solar charging fails or is interrupted.

AC Priority

In AC Priority mode, the detected AC input is prioritized for battery charging. If the AC power becomes unstable or unavailable, the unit will switch to solar charging.

Hybrid Charging

In Hybrid Charging mode, both solar and AC power charge the battery bank simultaneously, with solar power having priority. It utilizes MPPT for charging. If solar charging is insufficient, AC power supplements to supply the load. This mode offers the fastest charging and is suitable for areas with unstable grids, providing backup power support.

Solar Only Charging

Solar Only Charging is the most energy-efficient charging method for the battery and does not require AC input. In this mode, the battery is not charged even if AC power is available.

1.3. Load Output Operation Modes

The solar inverter has three operating modes that determine how the output power is supplied to the load. Users can configure the output power priority through these settings.

Solar Priority

In this mode, only solar and battery power are used to supply the load, maximizing the use of green energy and achieving overall energy saving and emission reduction. When solar energy is insufficient or the battery voltage drops to a low level, the unit will switch to AC power to continue supplying the load. This mode is recommended for areas with relatively stable grids.

AC Priority

This mode acts as a backup uninterrupted power supply for areas with unstable grids. AC power is prioritized for the load, and solar and battery power are only used when AC power is unavailable.

Inverter Mode

Battery power is used to supply the load. AC power will supply the load only when the battery voltage drops to the under-voltage level, maximizing the use of DC power.

2. Product Appearance

The PowMr POW-LVM3.5K-48V features a clear front panel with a display and controls, and various ports on the back for connections.

Key Components:

• 1. LCD Keypad
• 2. Mounting Holes
• 3. LCD Display
• 4. Indicator Lights
• 5. AC Input Circuit Breaker
• 6. Dry Contact Port
• 7. RS485 Communication Port
• 8. USB Debug Port (Internal Use)
• 9. AC Input Terminal
• 10. AC Output Terminal
• 11. Cooling Fan
• 12. PV Input Terminal
• 13. ON/OFF Rocker Switch
• 14. Battery Input Terminal
• 15. Grounding Lug

3. Dimensions

The unit has specific dimensions for installation:

• Length: 12.7 inches (322mm)
• Width: 4.88 inches (124mm)
• Height: 16.8 inches (426mm)

4. Installation

Please read this manual carefully and familiarize yourself with the installation process before proceeding.

4.1. Installation Safety

• The unit should be installed in a well-ventilated, cool, and dry environment. Ensure the unit's fans and ventilation openings are not obstructed.
• Do not expose the unit to rain, moisture, snow, or any other liquids.
• Do not install the unit in the same sealed enclosure as flooded-type batteries, as accumulated explosive gases pose an explosion risk.
• Do not install the inverter and battery bank in the same enclosure, as this may create a fire hazard.

4.2. Recommended Location

Ensure the installation complies with the following guidelines:

1. Cool, dry, well-ventilated area: High temperatures are detrimental to electronic equipment. The inverter must be installed where the fan is unobstructed, away from direct sunlight, and free from moisture. Maintain at least 8 inches (200mm) of clearance around the unit for adequate ventilation.
2. Fire Prevention: Keep the unit away from flammable materials and liquids. The unit may generate sparks. If flammable materials are nearby, the consequences can be severe.
3. Proximity to Battery Bank: Maintain a suitable distance between the unit and the battery bank, and use appropriately sized wiring to connect them, to prevent excessive voltage drop.
4. Minimize Battery Interference (EMI): Ensure the inverter is properly grounded to the building structure or vehicle. Keep the inverter away from EMI receivers such as televisions, radios, and other audio-visual electronic equipment to prevent damage or interference.

Other Precautions:

• Exercise caution when installing batteries. When installing lead-acid batteries, wear safety goggles. If battery acid comes into contact with skin, wash immediately with clean water.
• Avoid placing metal objects around the battery to prevent short circuits.
• Acidic gases may be produced during battery charging. Ensure adequate ventilation in the surrounding environment.
• Incorrect or improper wiring connections and corroded terminals can cause overheating, melting of insulation, ignition of surrounding materials, and even fire. Ensure all connections are secure.
• If wiring is loose or terminals are detached, avoid moving the unit. Outdoor installations should avoid direct sunlight and rain/snow.
• Do not install the solar inverter in environments that are humid, oily, flammable, explosive, or have high dust accumulation.
• AC input and AC output voltages are high. Do not touch the wiring. Do not touch the unit while the fan is running.
• To prevent damage, do not use multiple (parallel) AC input power sources.

Installation Clearance:

Note: For optimal cooling when the solar inverter's fan is operating, this position provides the best installation location for natural convection, enhancing overall efficiency.

4.3. Wiring

The PowMr solar inverter is designed for 24V battery systems. Failure to meet the minimum DC voltage requirements may cause irreversible damage to the unit.

The solar inverter's AC input/output terminals, battery terminals, and solar terminals handle high current. Ensure all wiring is carefully checked.

• Connect components to the corresponding labeled ports, paying attention to polarity. Reverse polarity may damage the components or the inverter.
• The inverter's input terminals have large capacitors. Once the positive and negative wires are connected to the terminals, the circuit will be energized, instantly drawing a large current. This may cause sparks and potentially shut down the inverter. To prevent sparks, it is recommended to use appropriately sized wiring for the solar inverter and/or install an additional fuse on the wiring leading to the inverter.
• Even with the power switch turned off, there is still a high voltage inside the solar inverter. Do not open or touch the inverter unit. Wait for the capacitors to discharge after operation before proceeding.

1. Ensure the power switch is in the OFF position on the solar inverter.
2. Loosen the screws on the solar inverter's surface and remove the terminal protection cover.

4.4. Battery Wiring

Caution: Incorrect polarity may damage the components or the inverter.

The inverter's input terminals contain large capacitors. Connecting the positive and negative wires to the terminals will energize the circuit and instantly draw a large current, potentially causing sparks and shutting down the inverter. To prevent sparks, use appropriately sized wiring for the solar inverter and/or install an additional fuse on the wiring to the inverter.

Battery Wiring Details:

• Ensure correct polarity; reverse polarity can damage the inverter.
• The inverter's input terminals have large capacitors. Connecting the wires will energize the circuit and draw significant current, potentially causing sparks or inverter shutdown. Use appropriate wire gauge and consider installing an additional fuse.
• Ensure all circuit breakers are open and the unit is turned off.
• The solar inverter operates with a 24V battery system. For 12V or 6V batteries, series connection is required to meet the minimum DC voltage requirement. Use ring terminals for battery cables, ensuring a secure and safe connection to the battery terminals to prevent overheating or high resistance. Connect the positive and negative battery ring terminals to the corresponding positive and negative battery terminals on the solar inverter.

4.5. PV Wiring

Maximum Solar Charging Current: 50A

Recommended Wiring: 7AWG

Recommended Circuit Breaker: 2-pole, 63A

For efficient charging of the 48V battery bank, a minimum open-circuit voltage of 60Vdc from the PV array is required. The solar inverter can accept a maximum input voltage of 150Vdc and requires a 48V battery input. This necessitates series connection of solar panels to achieve the minimum DC voltage requirement. Various factors affect PV performance. When connecting in series, refer to the open-circuit voltage (Voc) and ensure it remains within 150Vdc. For parallel connections, refer to the short-circuit current (Isc) and ensure it stays below the 50A limit.

Ensure PV wiring terminals are secure and safe to prevent overheating or high resistance. Connect the PV positive and negative wires to the corresponding PV terminals on the solar inverter.

4.6. AC Output Wiring

• Connect the live and neutral wires to the output terminals. The ground wire connects to the screw terminal.
• Ensure all circuit breakers are open and the unit is turned off.
• Do not connect the AC output to public power/grid or engine power.
• Do not misconnect the input and output terminals labeled "IN" and "OUT".

Maximum Inverter Bypass Current: 40A

Recommended Wiring: 7AWG

Recommended Circuit Breaker: 2-pole, 40A

Carefully insert the correct AC wiring into the AC output terminals. The ground cable should be connected to the ground screw terminal on the output terminal block. It is recommended to ground the solar inverter as effectively as possible, keeping the ground wire as short as possible, as shown in the diagram.

4.7. AC Input Wiring

• Do not connect AC input to AC output, as this may cause irreversible overload or damage.
• The AC input terminals are connected to circuit breakers for enhanced protection. Do not modify or alter them, as this may cause irreversible damage to the solar inverter.
• Do not misconnect the input and output terminals labeled "IN" and "OUT".

Route the AC input line through the AC input cable entry slot. When operating with AC power, ensure you use appropriately sized cables. Carefully connect the correct AC wiring to the corresponding AC input terminals, following the order shown in the diagram.

5. Communication Ports

5.1. Dry Contact

For this function to work, the controller for automatic start must be installed on the engine. From left to right, there are three terminals: NO, N, NC.

• Do not store equipment with automatic start functions; engines emit harmful gases when running.
• Terminal auto-start engine and charge battery bank. Normally, the NC-N terminal is closed, and the NO-N terminal is open. When the battery voltage reaches the low voltage point, the relay coil is energized, and the NO-N terminal closes while the NC-N terminal opens.
• The NO-N terminal can drive a 125Vac/1A or 30Vdc/1A resistive load.
• When connecting to an engine, the unit operates in "Charging Mode," where the generator's AC power charges the battery and supplies power to AC loads.

5.2. RS485

5.3. USB

The USB port is for internal use only. Due to proprietary information, it is not supported for user access.

If you need to use both USB and RS485 simultaneously, you can only choose one; both cannot be used at the same time.

6. Operation

Assuming all connections are correct and secure, turn on the main power switch of the solar inverter to the "ON" position.

Basic operation instructions for the solar inverter:

6.1. LCD Display Operation

The solar inverter is equipped with 3 indicator lights and 4 control buttons.

LCD Display Icons and Indicators

The LCD display shows various statuses and information:

• 1. Function indicator: Arrows shown only during startup, not part of the solar inverter's function.
• 2. AC/Grid power supply to load: Indicates AC/Grid power is supplying the load.
• 3. AC/Grid power supply to battery charging circuit (AC-DC): Indicates AC/Grid power is charging the battery.
• 4. Solar (PV) power supply to battery charging circuit (DC-DC): Indicates Solar (PV) power is charging the battery.
• 5. Charging current to battery: Indicates charging current is flowing to the battery.
• 6. AC/Grid power supply to inverter function: Arrows shown only during startup, not part of the solar inverter's function.
• 7. Battery power supply to inverter circuit (DC-AC): Indicates battery power is supplying the inverter.
• 8. Inverter circuit power supply to load: Indicates the inverter is supplying power to the load.

Indicator Icons and Their Meanings:

6.2. LCD Menu Interface

On the LCD display's home screen, scroll through the solar inverter's real-time data by pressing the "UP" and "DOWN" buttons.

Display Content:

• Left Side of LCD: AC (AC Input), PV (PV Input), INV (Inverter Circuit), WP (No Icon Display)
• Input/Output/Battery Charging/Temperature/Software Version: Displays battery voltage, total battery charging current, charging power, AC input voltage, AC input frequency, PV input voltage, internal heatsink temperature, and software version.
• Right Side of LCD: OUTPUTBATTLOAD displays output voltage, output current, output power, output apparent power, battery discharge current, and software version. In this setting mode, it displays the setting content for the code of the current setting parameter.

7. LCD Programmable Features

Press the "SET" button to enter the parameter setting mode. After entering the menu, parameter code 00 will flash. Press "UP" or "DOWN" to select the desired parameter code. To enter the parameter program, press "ENT" to enter the parameter editing state, and the parameter value will flash. Use the "UP" and "DOWN" buttons to adjust the parameter value. Finally, press "ENT" to complete the parameter editing and return to the parameter selection state.

When modifying parameters in custom or lithium battery modes, follow these rules for successful parameter setting:

1. Over-voltage Disconnect > Over-voltage Disconnect Recovery ≥ Equalization Voltage ≥ Boost Charging Voltage ≥ Float Charging Voltage
2. Over-voltage Disconnect > Over-voltage Disconnect Recovery
3. Under-voltage Disconnect Recovery > Under-voltage Disconnect (at least 2V lower) < Discharge Limit Voltage
4. Under-voltage Recovery > Under-voltage Warning

! If setting under-voltage disconnect in custom mode, it must always be at least 2V lower than the "under-voltage disconnect recovery voltage".

8. Electronic Protection

9. Fault Codes

10. Maintenance

For optimal long-term performance, it is recommended to inspect the following items twice a year:

1. Ensure the airflow around the solar inverter is unobstructed and clean any dust or debris from the heatsink.
2. Check all terminals for corrosion, damaged insulation, signs of overheating, or discoloration. Tighten terminal screws.

! Electric Shock Hazard! Before performing any checks or maintenance, ensure all power to the solar inverter is disconnected and all capacitors have fully discharged.

11. Specifications

11.1. Non-Lithium Battery Parameters

Rules for Custom Mode Parameter Settings:

1. Over-voltage Disconnect > Over-voltage Disconnect Recovery ≥ Equalization Voltage ≥ Boost Charging Voltage ≥ Float Charging Voltage
2. Over-voltage Disconnect > Over-voltage Disconnect Recovery
3. Under-voltage Disconnect Recovery > Under-voltage Disconnect (at least 2V lower) < Discharge Limit Voltage
4. Under-voltage Recovery > Under-voltage Warning

! If setting under-voltage disconnect in custom mode, it must always be at least 2V lower than the "under-voltage disconnect recovery voltage".

11.2. Lithium Battery Parameters

Rules for Custom Mode or Lithium Battery Mode Parameter Settings:

1. Over-voltage Disconnect > Over-voltage Disconnect Recovery ≥ Equalization Voltage ≥ Boost Charging Voltage ≥ Float Charging Voltage
2. Over-voltage Disconnect > Over-voltage Disconnect Recovery
3. Under-voltage Disconnect Recovery > Under-voltage Disconnect (at least 2V lower) < Discharge Limit Voltage
4. Under-voltage Recovery > Under-voltage Warning

! If setting under-voltage disconnect in custom mode, it must always be at least 2V lower than the "under-voltage disconnect recovery voltage".

12. Charging Parameter Glossary

• Over-voltage Disconnect: If the voltage controlled by the charging controller exceeds the rated value, the circuit will be disconnected, and charging will stop.
• Over-voltage Recovery: If the charging controller exceeds the over-voltage condition set by the previous parameter, the reconnection parameter will take effect. The controller will reconnect when it is safe to do so. Typically, over-voltage reconnection occurs after the over-voltage time expires (e.g., after sunset) or when the over-voltage condition is rectified and the voltage drops to the user-defined charging voltage.
• Equalization Voltage: Equalization voltage is a method to correct battery overcharging. Users should consult their battery manufacturer for specific battery equalization capabilities. This parameter sets the equalization voltage at which the battery reaches equalization status.
• Boost Voltage: Users should consult their battery manufacturer for correct charging parameters. At this stage, the user-set boost voltage will reach a specific voltage level and remain there until the battery enters the absorption phase.
• Float Voltage: Once the charging controller recognizes the set float voltage, the voltage will begin to float. In this state, the battery should be fully charged and maintained at a stable level by reducing the charging current.
• Under-voltage Alarm: When the battery voltage drops to a critically low level, close to the under-voltage disconnect point, loads are disconnected, and the battery is allowed to recover for a period. This parameter sets the controller to disconnect loads until it reaches the under-voltage reconnection phase.
• Under-voltage Recovery: This parameter allows loads to reconnect to the system and resume operation (when not fully charged).
• Under-voltage Disconnect: By automatically disconnecting loads, this prevents battery over-discharge, extending battery life. This is a prerequisite for entering the under-voltage state, under-voltage recovery, and eventual reconnection.
• Discharge Limit Voltage: This parameter ensures the controller does not exceed the default or specified parameter value before needing to recharge. It optimizes and extends battery life by using a higher voltage. A lower discharge limit voltage has a more severe negative impact on battery efficiency.

This equipment has been tested and complies with the limits for Class B digital devices, pursuant to Part 15 of the FCC Rules. These limits are designed to provide reasonable protection against harmful interference in residential installations. This equipment generates, uses, and can radiate radio frequency energy. If not installed and used according to the instructions, it may cause harmful interference to radio communications. However, there is no guarantee that interference will not occur in a particular installation. If this equipment does cause harmful interference to radio or television reception, which can be determined by turning the equipment off and on, users are encouraged to try to correct the interference by one or more of the following measures:

• Reorient or relocate the receiving antenna.
• Increase the separation between the equipment and the receiver.
• Connect the equipment to an outlet on a circuit different from that to which the receiver is connected.
• Consult the dealer or an experienced radio/TV technician for help.

This device complies with Part 15 of the FCC Rules. Operation is subject to the following two conditions:

• (1) This device may not cause harmful interference.
• (2) This device must accept any interference received, including interference that may cause undesired operation.