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Fault handling to clear the faults.

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Step 7

TC500K3US-O User Manual

In the case that the green light is on constantly, turn the key switch on the inverter panel from “OFF” to “ON”, the inverter will automatically enter the grid-connected working state. LED light immediately turns into the constantly on red light after grid connection is completed (when the red light is on constantly, it indicates that the grid-connected power generation of the inverter is successful). See the description of LED lights in Chapter 4 for details.

Once the inverter runs normally, no man-made interferences and controls are needed. It is necessary to open the inverter door only in case of maintenance and troubleshooting. Lock the inverter door with keys properly during normal operations. Keys shall be kept by a specially-assigned person, and the inverter door shall be opened by professional staff.

3.2 Startup in the Case of External Power Supply of Control

Power

The control power of TC500K3US-O PV grid-controlled inverter is divided into 2 operating conditions, internal power supply and external power supply:

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External power supply

TC500K3US-O User Manual

The AC voltage source (applicable to the range of 176V AC -220V AC) required by the inverter control system shall be provided from the external power supply of the inverter. See details for accessing control power for external power supply in the control power system in the installation manual of

TC500K3US-O PV grid-connected inverters. The energizing air-switch position of external control power is as shown in Figure 3-2.

Figure 3-2 Energizing air-switch of external power supply

(1) All connections are carried out in accordance with the installation manual and circuit diagrams.

(2) Ensure that the inverter has made protective grounding connections for the strong current at AC and DC sides and the system control power supply.

(3) The startup key is at the “OFF” position.

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(4) The emergency stop button is pressed.

TC500K3US-O User Manual

(5) The AC and DC circuit breakers are at the “OFF” position, and installed with protective covers.

(6) Check the lines, and make sure the connecting cables are correct.

(7) Measure with a multimeter and make sure that the grid voltage is normal.

(8) Check PV modules VIA insulation tests to ensure there is no ground fault.

If conditions permit, use oscilloscopes and other related equipments to check whether the grid voltage frequency and the phase sequence at the connecting side of the grid and the inverter are normal as far as possible

(the frequency is within the range of 59.8Hz-60.5Hz), otherwise, it will lead to failure of the inverter startup.

When the above meets the normal startup requirements, carry out the following operations:

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Step 1

Check whether the air-switch of external control power of DC side inverter door is closed, if not, please close the air-switch of control power. And use a multimeter to measure whether the input voltage of AC control power is

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TC500K3US-O User Manual normal (within the range of 176V-220V). If not, please adjust the output voltage of the external power supply voltage source to the normal range

(176V-220V). After the external control power is normal, enter Step 2.

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Step 2

After the energizing process of the external power supply of control power is completed, immediately check whether LCD display is started normally, if everything is normal, the control power is energized successfully, then enter into Step 3.

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Step 3

Close the inverter door at the inverter AC side, and turn the circuit breaker of the inverter at AC side from “OFF” to “ON”, the closing of AC side circuit breaker is completed. Observe whether the AC side voltage displayed on LCD display is normal, if not normal, please refer to Chapter 8 Grid overvoltage or under-voltage fault handling.

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Step 4

Close the combiner boxes of all lines in sequence, and check whether combiner boxes operate properly, if normal, then enter into Step 5.

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Step 5

Close the inverter door at the inverter DC side, and turn the circuit breaker of the inverter at DC side from “OFF” to “ON”, the closing of DC side circuit

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TC500K3US-O User Manual breaker is completed. Observe whether the DC side voltage on LCD display is normal. If not, please refer to Chapter 8 DC side overvoltage and under-voltage faults handling.

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Step 6

Observe whether the voltage at AC and DC sides on LCD display is normal again, if the voltage at both sides is within the normal startup voltage range, then screw on the emergency stop button. It can be observed that the panel LED lights change from the flashing yellow light to the constantly on green light immediately (the display status and logic of LED lights on the panel refer to the description contents of LED lights in Chapter 4). If the LED light on the panel is not the constantly on green light, it proves that the inverter has faults, please check the fault records on the LCD display or the fault records on the background monitoring interface immediately, and then refer to Chapter 8

Fault handling to clear the faults.



Step 7

In the case that the green light is on constantly, turn the key switch on the inverter panel from “OFF” to “ON”, the inverter will automatically enter the grid-connected working state. LED light immediately turns into the constantly on red light after grid connection is completed (when the red light is on constantly, it indicates that the grid-connected power generation of the inverter is successful). See the description of LED lights in Chapter 4 for details.

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