How Does the PV Array DC Isolator Switch Protect the Photovoltaic System?

PV array DC isolator switch, as the name suggests, is a switch that isolates DC. It is mostly used in photovoltaic power station systems, and is used between high-voltage DC photovoltaic arrays and grid-connected inverters to cut off arcs generated by DC power, avoid dangerous accidents, and ensure safe operation. They are located near the inverter and require a means of manually isolating the entire PV array during system installation or any subsequent maintenance.

What are the Protection Functions of the PV Array DC Isolator Switch?

(1) When installing a photovoltaic system, the installer usually turns off the DC switch first to isolate the input of the solar panel from the inverter. During this wiring and plugging of the DC terminals, the DC power is not connected to the DC side of the inverter to prevent personal electric shock and damage to the inverter and back-end equipment. Therefore, when installing the system, we need a PV array dc isolator to isolate the DC power between the inverter and the battery panel.

(2) In a photovoltaic power station, the inverter is the “core center”. In order to ensure sufficient power generation time, the inverter does not have a start-stop button. As long as there is light (even in rainy weather), the solar panels can generate electricity and the inverter can work automatically. However, this also brings up a problem. When replacing or repairing the inverter, even though the AC side has been disconnected by the installed AC circuit breaker, the DC side is always energized. In this case, if the inverter does not have a solar array dc isolator switch to isolate the DC power of the panels, it is easy to cause electric shock and equipment damage.

(3) At present, most of the inverters on the market are of TL series, that is, there is no electrical isolation inside, and there is a possibility of reverse flow from the AC side to the DC side. During maintenance, if the AC switch and DC switch are physically isolated, it can be more safely protected.

Different Installation Types

There are 5 installation types: Single-hole mounting type, Panel mounting type, Rail mounting type, Door lock mounting type, and External mounting type.

Features of Mingguan PV Array DC Isolators:

1. Especially designed for DC application, rated current range 16~630A, voltage range: ≤1500V, suitable for various applications;

2. Different installation methods and modular design give the product installation flexibility;

3. Electric shock self-cleaning design, reduces resistance and energy consumption, and prolongs service life;

4. Number of poles: 2~10 levels optional;

5. Maximum on-off time: less than 5ms

6. Imported UL94V-0 flame retardant materials are used, which can be used in harsh application environments;

7. Comply with various standards (such as IEC, UL, TUV, CE, CB, SAA, CCC, etc.)

Mingguan can produce PV array isolators suitable for a full range of string inverters from 1KW to 320KW. It is a supplier of DC isolator switches in compliance with IEC60947-3(ed.3.2):2015 and has obtained UL certification.

These products complying with the latest photovoltaic standards can meet the broad needs of the global photovoltaic market and can solve customers’ worries about system safety and protection. Slocable will continue to conduct in-depth research to provide the market with more diversified and better choices.