COTEK SD Series Pure Sine Wave Inverter

Comprehensive Technical Analysis and Application Guide for SD Series Pure Sine Wave Inverter

Product Overview and Core Features

The SD series pure sine wave inverter is a new generation of power conversion equipment launched by COTEK Electronic IND. CO. It covers three power levels: SD1500, SD2500, and SD3500, supports 12V, 24V, and 48V DC inputs, and provides two AC output specifications: 100-120VAC and 200-240VAC. This series of inverters adopts advanced pure sine wave output technology to ensure stable and clean power supply for various sensitive electronic devices, especially suitable for scenarios such as RVs, ships, solar off grid systems, and industrial backup power sources.

The core design concept of the SD series is "flexibility and reliability". It has N+1 parallel redundancy function, and users can achieve power expansion or system redundancy by paralleling up to 5 devices, significantly improving the reliability and capacity of the power supply system. In addition, the inverter is equipped with an automatic transfer switch (ATS), which supports seamless switching between mains power and inverter output, and can be optionally equipped with a static transfer switch (STS) module to shorten the switching time to less than 4 milliseconds, meeting the extremely high requirements for power continuity in application environments.

In terms of protection mechanisms, the SD series provides comprehensive input and output protection functions, including reverse connection protection (implemented through fuses), undervoltage protection, overvoltage protection, short circuit protection, overload protection, over temperature protection, etc. These protective functions not only extend the lifespan of the equipment itself, but also greatly enhance the safety of the entire electrical system.

In depth analysis of electrical performance

The electrical performance of each model in the SD series has been carefully designed to adapt to different load requirements and environmental conditions. Taking the SD2500 model as an example, describe its key parameters in detail:

Output capability: The rated power is 2500VA, and the derating curve should be referred to when the ambient temperature is above 40 ° C. The device has short-term overload capability, with peak power (lasting for 3 seconds) reaching 3000-4000VA and surge power (lasting for 0.2 seconds) exceeding 4000VA, making it easy to start inductive loads such as motors.

Waveform quality: The output is a pure sine wave, with a total harmonic distortion (THD) of less than 3% under rated conditions, ensuring compatibility with precision electrical appliances such as laptops and medical equipment, and avoiding damage or interference.

Conversion efficiency: The maximum conversion efficiency can reach up to 90%, especially in energy-saving mode, with extremely low no-load power consumption (such as only 0.3A in 48V model energy-saving mode), effectively reducing energy waste and extending battery life.

Input/output range: Wide DC input voltage range (e.g. 20.0-32.0VDC for 24V models), suitable for battery voltage fluctuations. The communication input has a wide voltage adaptation range of ± 12.5% and supports 50/60Hz frequency selection and synchronization.

All models can operate in ambient temperatures ranging from -20 ° C to+60 ° C, with a wider storage temperature range of -40 ° C to+70 ° C, demonstrating strong environmental adaptability. The equipment has passed safety certifications such as UL 458 (hardware part) and EN 62368-1, as well as electromagnetic compatibility certifications such as FCC Class B and EN 55032, ensuring reliable quality.

Safety instructions and installation specifications

Safety is the primary prerequisite for the use of electrical equipment. The SD series manual emphasizes important safety information at the beginning.

1. General safety precautions:

Environmental requirements: The inverter must be installed in a dry, cool, well ventilated, and dust-free environment. The ambient temperature should be between -20 ° C and 50 ° C, and a gap of at least 30 centimeters should be maintained around to ensure smooth heat dissipation. It is strictly prohibited to install in places with combustible gases (such as engine compartments, fuel storage areas) or metal dust or sawdust flying.

Battery safety: Wear protective equipment when operating the battery to avoid metal objects short circuiting the battery terminals and generating arcs. The inverter should be installed close to the battery to reduce line loss, but it must not be placed in the same enclosed space as the battery to prevent corrosive gases generated by the battery from damaging the equipment.

Electrical safety: Before performing any wiring operation, it is necessary to confirm that the inverter has been disconnected from all power sources (batteries and AC power). It is strictly prohibited to connect the output terminal to an external AC power source.

2. Key points for DC wiring installation:

Cable selection: High quality copper cables must be used and the length should be minimized as much as possible (ideally less than 1.8 meters). The cable cross-section should be strictly selected according to the model and current. For example, the SD3500-112 model recommends using a 4/0 AWG (approximately 120mm ²) cable and is equipped with a 500A DC fuse. The fuse must be installed on the positive (+) cable.