Fuji Electric FRENIC-MEGA, Инструкция по эксплуатации

Страница: 329 / 358

7-4
Ch
ap
. 7
MAINTENAN
C
E AND
INSPE
C
T
ION
„
Notes for the judgment on the service life of the DC link bus capacitor
The service life of the DC link bus capacitor can be judged by the "measurement of discharging time" or "ON-time counting."
Measurement of discharging time
- The discharging time of the DC link bus capacitor depends largely on the inverter's internal load conditions, e.g. options attached
or ON/OFF of digital I/O signals. If actual load conditions are so different from the ones at which the initial/reference capacitance
is measured that the measurement result falls out of the accuracy level required, then the inverter does not perform measuring.
- The capacitance measuring conditions at shipment are extremely restricted, e.g., all input terminals being OFF, in order to
stabilize the load and measure the capacitance accurately. Those conditions are, therefore, different from the actual operating
conditions in almost all cases. If the actual operating conditions are the same as those at shipment, shutting down the inverter
power automatically measures the discharging time; however, if they are different, no automatic measurement is performed. To
perform it, put those conditions back to the factory default ones and shut down the inverter. For the measuring procedure, see [ 1 ]
given below.
- To measure the capacitance of the DC link bus capacitor under ordinary operating conditions when the power is turned OFF, it is
necessary to set up the load conditions for ordinary operation and measure the reference capacitance (initial setting) when the
inverter is introduced. For the reference capacitance setup procedure, see [ 2 ] given on the next page. Performing the setup
procedure automatically detects and saves the measuring conditions of the DC link bus capacitor.
Setting bit 3 of H98 data to 0 restores the inverter to the measurement in comparison with the initial capacitance measured at
shipment.
When the inverter uses an auxiliary control power input, the load conditions widely differ so that the discharging time
cannot be accurately measured. To prevent unintended measuring, the discharging time measurement can be disabled with
the function code H98 (Bit 4 = 0).
ON-time counting
- In a machinery system where the inverter main power is rarely shut down, the inverter cannot measure the discharging time. For
such a case, ON-time counting is provided. The ON-time counting result can be represented as "elapsed hours" (Menu #5 "5.
MAINTENANC," Page 8, CAPEH) and "remaining hours" (Menu #5 "5. MAINTENANC," Page 8, CAPRH) as shown in Table
7.3, "On the LCD monitor."
[ 1 ] Measuring the capacitance of DC link bus capacitor in comparison with initial one at shipment
When bit 3 of H98 data is 0, the measuring procedure given below measures the capacitance of DC link bus capacitor in comparison
with initial one at shipment when the power is turned OFF. The measuring result can be displayed on the keypad as a ratio (%) to the
initial capacitance.
----------------------------------------------------- Capacitance measuring procedure ----------------------------------------------------------
1) To ensure validity in the comparative measurement, put the condition of the inverter back to the state at factory shipment.
•
If the original keypad has been replaced with an optional remote keypad (equipped with a USB port), replace the remote one
with the original one.
•
Remove the option card (if already in use) from the inverter.
•
In case another inverter is connected via the DC link bus to the P(+) and N(-) terminals of the main circuit, disconnect the wires.
(You do not need to disconnect a DC reactor (optional), if any.)
•
Disconnect power wires for the auxiliary input to the control circuit (R0, T0).
•
Mount the remote keypad on the inverter.
•
Turn OFF all the digital input signals fed to terminals [FWD], [REV], and [X1] through [X7] of the control circuit.
•
If an external frequency command potentiometer is connected to terminal [13], disconnect it.
•
If an external apparatus is attached to terminal [PLC], disconnect it.
•
Ensure that transistor output signals ([Y1] to [Y4]) and relay output signals ([Y5A] - [Y5C], and [30A/B/C]) will not be turned
ON.
•
Disable the RS-485 communications link.
It is recommended that terminal [EN] be short-circuited for the measurement of the capacitance.
If negative logic is specified for the transistor output and relay output signals, they are considered ON when the
inverter is not running. Specify positive logic for them.
•
Keep the surrounding temperature within 25
±
10
°
C (77
±
50
°
F).
2) Turn ON the main circuit power.
3) Confirm that the cooling fan is rotating and the inverter is in stopped state.
4) Turn OFF the main circuit power.