Wiring and Installation Tips for Rapid Shutdown Devices

Now many people know that Rapid Shutdown Devices (RSDs) are crucial in the photovoltaic industry. But how to install an RSD? What should be noted during wiring? Don’t worry—we’ll explain it step by step. Read through this before installation to ensure twice the result with half the effort.

I. Prepare Tools First: These 5 Items—Fonrich’s Included Accessories Save a Lot of Trouble

Before installing the RSD, gather the necessary tools and accessories to avoid missing items midway:

• Screwdrivers: One Phillips and one flathead. Fonrich RSD’s terminal blocks are standard-sized, so regular screwdrivers can tighten them.
• Wire Stripper: Do not use scissors to strip wires (they easily damage the copper core). Choose a stripper with scale marks—perfect for 1.5-2.5mm² wires.
• Multimeter: Measure voltage during installation to ensure no reverse connection or short circuit.
• Insulating Tape: Wrap the wiring joints twice to prevent leakage (Fonrich RSD comes with insulated terminals, so tape is optional).

• Marker Pen: Label cables (e.g., "Module Positive," "Inverter Negative") for easy identification during later maintenance.

II. Must-Do Before Wiring: 3 Steps to Prevent Installation Errors and Rework

Don’t start wiring immediately! Complete these 3 steps first—they prevent 90% of rework:

1. Verify RSD Model Matches System VoltageMost residential PV systems are 600V DC. Choose the correct RSD model: For example, Fonrich RSD-F100 supports 120V-1500V (compatible with 600V and 1000V systems), but using an RSD only supporting 300V will burn the equipment.
2. Power Off! Power Off! Power Off!Cut off the main switch of the PV modules before installation. Use a multimeter to confirm the DC-side voltage is 0V before proceeding.
3. Clarify Cable Direction: Do Not Mix Up "Module Side" and "Inverter Side"RSD has two types of interfaces: Input (connects to modules) and Output (connects to inverter). Fonrich RSD is clearly marked with "IN" (for modules) and "OUT" (for inverter)—do not reverse them! Reverse connection will prevent the RSD from triggering shutdown and may burn internal components.

III. Wiring Practice: 4 Steps to Complete—Fonrich’s Error-Proof Design Is Super User-Friendly

Taking Fonrich RSD-F100 as an example, wiring only takes 4 steps—even beginners can finish in half an hour:

1. Strip Wires: Expose 1.5cm of Copper Core (Not Too Long or Too Short)Use the wire stripper to remove the cable insulation, exposing approximately 1.5cm of copper core. Too short causes poor contact; too long risks short-circuiting against the base. Fonrich RSD’s terminal blocks have a "positioning design"—the copper core fits perfectly when inserted all the way, no need for repeated length adjustments.
2. Positive/Negative Wiring: Fonrich’s Color Marking Is ClearModule and inverter cables are color-coded (usually red for positive, black for negative). Match them as follows:

• RSD "IN+" connects to Module Positive; RSD "IN-" connects to Module Negative.
• RSD "OUT+" connects to Inverter Positive; RSD "OUT-" connects to Inverter Negative.Fonrich RSD’s terminals also have an "anti-reverse lock"—beginners won’t make mistakes, much more reliable than other brands’ "non-error-proof designs."

3. Tighten Terminals: Apply Adequate Force to Avoid Loose ConnectionsUse a screwdriver to tighten the terminal screws—tight enough so the copper core doesn’t wobble. Too loose causes poor contact and overheating; too tight crushes the copper core.
4. Connect Communication Cable (Optional): Fonrich Supports APP Monitoring—Wiring Is Super SimpleIf you want to connect to a mobile app for monitoring, plug the RSD’s communication cable (usually two-core) into the inverter’s communication port. Fonrich RSD’s communication interface is universal—no soldering required, just plug and secure.

IV. Post-Installation Must-Do: 3 Tests to Ensure RSD Works Normally

Don’t put away tools after wiring! Conduct these 3 tests to confirm functionality before powering on:

1. Manual Test: Press the "TEST" button on the RSD to check if it cuts off voltage within 30 seconds (Fonrich RSD lights up red to indicate shutdown, green when normal).
2. Multimeter Test: After powering on, the output voltage of the RSD should match the module voltage. No voltage indicates a loose connection.
3. Simulated Fault Test: Use an insulated rod to gently touch the module cables (do not use hands!) to simulate a mild short circuit. Check if the RSD triggers an alarm—Fonrich RSD responds within 0.05 seconds, twice as fast as the standard.

V. Pitfall Warnings: Avoid These 3 Mistakes—Many People Have Fallen for Them

• Do not install the RSD in exposed or waterlogged areas: Choose a well-ventilated, shaded location (e.g., inside a distribution cabinet). Although Fonrich RSD withstands 60℃ high temperatures, long-term exposure shortens its service life.
• Do not skip terminal blocks: Some people save costs by twisting cables directly onto screws without terminals—this causes poor contact due to oxidation over time. Fonrich RSD comes with terminals, so don’t waste them.
• Do not forget to attach labels: Stick a "Rapid Shutdown Device" label near the RSD for easy identification during maintenance and for firefighters to quickly locate it during emergencies.

Final Summary: RSD Wiring and Installation Isn’t That Hard

The key is to "verify the model, operate with power off, and distinguish positive/negative." Beginners can choose error-proof brands like Fonrich for one-time correct installation. If you encounter problems during installation, don’t insist—contact the brand’s after-sales service. Fonrich has service stations nationwide, and technicians can provide remote guidance, which is better than struggling blindly. Remember: Safety first, compliance second. Install the RSD correctly, and your PV system can be used with peace of mind!