7-6
Cooling
fan
Select Menu #5 "Maintenance Information" and check the cumulative run time of the cooling fan. The
inverter accumulates hours for which the cooling fan has run. The display is in units of 1000 hours.
The cumulative time should be used just a guide since the actual service life will be significantly
affected by the temperature and operation environment.
(2) Early warning of lifetime alarm
For the components listed in Table 7.3, you can get an early warning of lifetime alarm at the transistor
output terminal [Y1] and the relay contact terminals [30A/B/C] as soon as any of the conditions listed
under the "Judgment level" column has been exceeded. When the replacement data of any parts
exceeds the judgment level, this signal comes ON.
Table 7.3 Criteria for Issuing a Lifetime Alarm
Parts to be replaced
Judgment level
DC link bus capacitor
85% or lower of the initial capacitance at shipment
Electrolytic capacitors on the
printed circuit boards
87000 hours or longer as cumulative run time
(Estimated service life at the inverter’s ambient temperature of
40
°
C under 80% of full load when running 12 hours/day)
Cooling fan
87000 hours or longer as cumulative run time
(Estimated service life at the inverter’s ambient temperature of
40
°
C under 80% of full load when running 12 hours/day)
7.4
4B
Measurement of Electrical Amounts in Main Circuit
Because the voltage and current of the power supply (input, primary circuit) of the main circuit of the
inverter and those of the motor (output, secondary circuit) contain harmonic components, the
readings may vary with the type of the meter. Use meters indicated in Table 7.4 when measuring with
meters for commercial frequencies.
The power factor cannot be measured by a commercially available power-factor meter that
measures the phase difference between the voltage and current. To obtain the power factor,
measure the power, voltage and current on each of the input and output sides and use the following
formula.
Three-phase input
Single-phase input
%
100
×
(A)
t
(V)×Curren
×Voltage
3
(W)
power
Electric
=
factor
Power
%
100
×
(A)
Current
×
(V)
Voltage
(W)
power
Electric
=
factor
Power