Connecting the DC input power cable

Precautions

• Before connecting the DC input power cable, ensure that the DC voltage is within the safe range (lower than 60 V DC), and that the DC SWITCH is set to the OFF position. Failure to do so could generate high voltage, which may cause electric shocks.
• When the SUN2000 is operating, it is not allowed to operate the DC input power cable, such as connecting or disconnecting a PV string or a PV module in a PV string. Failing to do so may cause electric shocks.
• If no PV string is connected to a DC input terminal of the SUN2000, do not remove the watertight cap from the terminal. Otherwise, the IP rating of the SUN2000 will be affected.

Ensure that the following conditions are met. Otherwise, the SUN2000 may be damaged, or even a fire could happen.

• PV modules connected in series in each PV string are of the same specifications.
• The open-circuit voltage of each PV string is always lower than or equal to 1080 V DC.
• The maximum short-circuit current of each PV string must be lower than or equal to 15 A.
• The DC input power cable is correctly connected. The positive and negative terminals of a PV module are connected to corresponding positive and negative DC input terminals of the SUN2000.
• If the DC input power cable is reversely connected, do not operate the DC switch and positive and negative connectors. Wait until the solar irradiance declines at night and the PV string current reduces to below 0.5 A, and then turn off the DC switch. Remove the positive and negative connectors to correct the polarity.

• Because the output of the PV string connected to the SUN2000 cannot be grounded, ensure that the PV module output is insulated to ground.
• The PV strings connecting to the same MPPT circuit should contain PV modules of the same model and quantity.
• During the installation of PV strings and the SUN2000, the positive or negative terminals of PV strings may be short-circuited to ground if power cables are not properly installed or routed. An AC or DC short circuit may occur and damage the device when the SUN2000 is operating. The caused device damage is not covered under any warranty.

Terminal Description

Figure 5-12 Terminals

It is recommended that the number of PV modules connected to PV1 and PV2 be the same, and that the number of PV modules connected to PV3 and PV4 be the same.

Procedure

1. Connect the DC input power cable.

   Before inserting the positive and negative connectors into the positive and negative DC input terminals of the SUN2000, check that the DC SWITCH is OFF.

   Use the Amphenol Helios H4 PV connectors supplied with the SUN2000. If the PV connectors are lost or damaged, purchase the connectors of the same model. The device damage caused by incompatible PV connectors is not covered under any warranty.

   • Cables with high rigidity, such as armored cables, are not recommended as DC input power cables, because poor contact may be caused by the bending of the cables.
   • Before assembling DC connectors, label the cable polarities correctly to ensure correct cable connections.
   • After crimping the positive and negative metal contacts, pull the DC input power cables back to ensure that they are connected securely.
   • Insert the crimped metal contacts of the positive and negative power cables into the appropriate positive and negative connectors. Then pull back the DC input power cables to ensure that they are connected securely.

   • Crimp the metal stamping forming contacts using crimping tool H4TC0003 (Amphenol, recommended), H4TC0002 (Amphenol), PV-CZM-22100 (Staubli), or PV-CZM-19100 (Staubli). When choosing PV-CZM-22100 or PV-CZM-19100, do not use the locator. Otherwise metal contacts would be damaged.
   Figure 5-13 Crimping tool (H4TC0003)
   

   (1) Locator

   • The DC voltage measurement range of the multimeter must be at least 1100 V.
   • If the voltage is a negative value, the DC input polarity is incorrect and needs correction.
   • If the voltage is greater than 1080 V, too many PV modules configured in the same string. Remove some PV modules.
   Figure 5-14 Connecting the DC input power cable
   

   If the DC input power cable is reversely connected and the DC SWITCH is set to the ON position, do not operate the DC SWITCH and positive and negative connectors. Otherwise, the device may be damaged. The caused device damage is not covered under any warranty. Wait until the solar irradiance declines and the PV string current drops to below 0.5 A. Then set the two DC SWITCH to the OFF position, remove the positive and negative connectors, and rectify the connection of the DC input power cable.

Removing a DC connector

Before removing the positive and negative connectors, ensure that the DC SWITCH is OFF.

To remove the positive and negative connectors from the SUN2000, insert an open-end wrench into the notch and press hard to remove the DC connector.

Figure 5-15 Removing a DC connector