CPWR-AN26, Rev A, 08-2018
Copyright © 2018 Cree, Inc. All rights reserved.
The information in this document is subject to change without notice.
Cree and Zero Recovery are registered trademarks, and the Cree logo and C3M are trademarks, of Cree, Inc
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Switch OFF the +15V and +24V power supplies first
.
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Switch OFF +7V power supply. The +7V must be turned OFF last since it serves as the
DSP supply voltage. Failure to turn OFF the +7V last may cause damage to the circuit.
Please take the following steps in order when starting the unit in DC/AC grid connected mode:
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If the board is being tested for the first time, follow the procedures described at the
beginning of Section 7.
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The board should be connected as shown in Figure 7.
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Keep MCB1 (DC supply) in open position
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Keep output isolated from grid AC Voltage by keeping MCB2 in open position.
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Put ON/OFF switch (sw2) in OFF position
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Put mode switch (sw1) in DC/AC position.
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C7V supply to J7 (positive (+) to pin 1 and negative (-) to pin 2). Confirm that
the current drawn from the 7V supply is similar to the value specified in Table 5.
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Switch ON +15V, +15V_1 and the power supplies and confirm that the current drawn is
same mentioned as in table 5.
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Set the required peak grid current as per Table 7.
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Check the grid voltage, which should be between 105 VAC - 230 VAC.
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Close MCB2, tying the output of the converter to the grid. Relay connect sound should
be audible after few seconds.
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Check for the DC link voltage with the help of a multimeter. It should be similar to the
peak of the input AC voltage. Confirm that the output voltage frequency is 50Hz or 60Hz
as per Table 4.
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LED (D10) indication (as shown in Table 4) must match the grid frequency. If it does not
match then switch OFF the grid voltage and then switch it ON again.
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Turn ON the 24V supply and a cooling fan that should be attached to the supply.
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Close MCB1 and slowly increase the DC supply voltage to the required value (320 VDC
to 450 VDC). DC supply voltage should be increased gradually because there is no inrush
current limiter at this end.
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Put sw2 in ON position and check the input and output voltages
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Check for the overall efficiency of the DC/AC stage and the THD.
Please take the following steps in order when stopping the unit in DC/AC grid connected mode:
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Decrease the output load in steps no greater than 1 kW (MAXIMUM) until no load.
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Put switch sw2 into the OFF position.
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Open MCB2 disconnecting the output from the grid.
