The ERP Series DC Rapid Shutdown Switch Device RSD (PV firefighter safe switch) which can achieve module-level rapid shutdown. Which in turn will significantly improve thesafety of PV power generation systems. RSD uses PLC communication. The signalis transmitted by the inverter with built-in transmitter function through the DC bus.After The ERP RSD receives the signal, the switch turns on and the energy generated by the PV module will be delivered to the AC grid through the inverter: When an emergency situation occurs, the AC power can be turned off by switching off the AC breaker inthe cabinet, so that the inverter with built-in transmitter function stops sending signals,and the ERP RSD will shutdown the power output, then eliminate the high voltage on DC bus, it can improve the safety of the PV system.
The ERP Series DC Rapid Shutdown system is comprised of three key elements:
*PV array
*Rapid shutdown Device RSD
*Inverter with built-in transmitter function
The ERP DC Rapid Shutdown Switch Device is mounted on the aluminum frame of the PV module. The output connectorof each PV module is connected to the The ERP DC Rapid Shutdown Switch Device input connector (black cable), and theadjacent two Rapid Shutdown Switch Devices in each string are connected through the output connector(red cable). Finally, the entire string is connected to the inverter. Up to 10 strings of PV modules can be connected in parallel in the system. Each string of PV modules containsat least 6PC the ERP DC Rapid Shutdown Switch Device and no more than 30PCS the ERP DC Rapid Shutdown Switch Device.
Tum-on Mode of DC Rapid Shutdown Switch Device
When the AC breaker is closed, the inverter with built-in transmitter functionsends the signal keep alive through the DC bus. The ERP DC Rapid Shutdown Switch Device receives the signal andenters the turn-on mode. Then the MOSFET Q3 is turned off and the MOSFET Q2/Q20 is turned on. DC Rapid Shutdown Switch Device turns on and the energy generated by the PV module will be delivered to the AC grid through the inverter.
Initiating Rapid Shutdown
When the AC breaker is tured off, the inverter with built-in transmitter function stopssending the signal keep alive through the DC bus. JMS-F does not receive the signal andwaits for 10 seconds to enter the turn-off mode. Then the MOSFET Q3 is activated andthe MOSFET Q2/Q20 is deactivated, the output voltage of DC Rapid Shutdown Switch Device RSD is 1 Volt, and the PVsystem is in the no-load state.
Rapid shutdown steps
STEP1: Switch off the AC breaker on the AC side of the PV system.
STEP2: The inverter with built-in transmitter function stops sending signals, thus initiating rapid shutdown.
STEP3: Each DC Rapid Shutdown Switch Device RSD does not receive the signal then executing rapid shutdown, theoutput voltage of each DC Rapid Shutdown Switch Device RSD is 1 Volt.
STEP4: At the final stage the DC bus voltage of the PV system drops to below 30 Volts within 30 seconds.
Controlled Conductor
The ERP Series DC Rapid Shutdown Switch Device RSD can detect any rapid disconnection between each PV module incritical situations, thus eliminating the DC high voltage present in the PV system array,reduces the risk of electric shocks for rescue operation. The ERP Series DC Rapid Shutdown Switch Device RSD achieves shutdownwithin 10 seconds, the voltage is reduced to less than 80 Volts within the distance limitof 1 foot from the PV array, while the DC cable voltage from 1 foot outside the PV arrayto the inverter input drops below 30 Volts.
Installation Steps
The ERP Series DC Rapid Shutdown Switch Device RSD installation is straight forward. All the ERP Series DC Rapid Shutdown Switch Device RSD units comes equipped with a metal buckle that can be easily attached to the aluminum frame of the PV module. Simply insert the buckle of the RSD into the aluminum frame of the PV module and makesure that the installation is firm.
A.Install the ERP RSD onto the PV module
B.The connection between two adjacent the ERS RSD
C.Connecting the parallel the ERP RSD strings to the inverter.
System Installatlon Test
After completion of the RSD installation based on the specified instructions above, a system installation test must be performed.
Start by switching on the DC side switch, then continue with the AC side.Verify that each RSD in the system is on “power up” mode and the outputvoltage matches the voltage of the PV module.The next step is to switch off the AC side, and verify each RSD in the systemis on the “power off mode and output voltage is at 1 Volt.
Replace a RSD
Follow the procedure to replace a RSD:
in the order shown below.
(1) Disconnect the AC by switching off the AC side switch.
(2) Disconnect the DC by switching off the DC side switch of the inverter.
(3) Wait for at least 5 minutes after switching off the power and then disconnect the PV module with the RSD.
(4) Remove the RSD from the aluminum frame of the PV module.
(5) Install a replacement RSD to the aluminum frame of the PV module.
(6) Switch on the DC side switch and then switch on the AC side switch and recover thesystem.