Mitsubishi Electric FR-A720-0.4K Instruction Manual page 294

(6) Annual power saving amount, power cost (Pr. 899)
⋅ By setting the operation time rate [%] (ratio of time when the motor is actually driven by the inverter during a year)
in Pr. 899, the annual energy saving effect can be predicted.
⋅ When the operation pattern is predetermined to some degree, the estimated value of the annual power saving
amount can be found by measurement of the power saving amount during a given measurement period.
⋅ Refer to the following and set the operation time rate.
1) Predict the average time [h/day] of operation in a day.
2) Find the annual operation days [days/year]. (Monthly average operation days × 12 months)
3) Calculate the annual operation time [h/year] from 1) and 2).
Annual operation time (h/year) = Average time (h/day)
4) Calculate the operation time rate and set it to Pr. 899.
Operation time rate (%) =
REMARKS
⋅ Operation time rate setting example: When operation is performed for about 21 hours per day and the monthly average
operation days are 16 days
Annual operation time = 21 (h/day) × 16 (days/month) × 12 months = 4032 (h/year)
Operation time rate (%) =
Set 46.03% to Pr. 899.
⋅ Calculate the annual power saving amount from Pr. 899 Operation time rate (estimated value) and power saving
average value monitor
Annual power saving amount (kWh/year) =
⋅ The annual power saving amount charge can be monitored by setting the power charge per hour in Pr. 896 Power
unit cost.
Calculate the annual power saving amount charge in the following method.
Annual power saving amount charge = Annual power saving amount (kWh/year) ×
REMARKS
In the regeneration mode, make calculation on the assumption that "power saving = power during commercial power supply
operation (input power = 0)".
♦ Parameters referred to ♦
Pr. 3 Base frequency Refer to page 159
Pr. 52 DU/PU main display data selection
Pr. 54 FM terminal function selection
Pr. 158 AM terminal function selection
Annual operation time (h/year)
24 (h/day) × 365 (days/year)
4032 (h/year)
× 100(%) = 46.03%
24 (h/day) × 365 (days/year)
Refer to page 253
Refer to page 253
Refer to page 253
Energy saving operation and energy saving monitor
× Operation days (days/year)
× 100(%)
Power saving average value
(kW) during totalization
when Pr. 898 = 10 or 9999
Pr. 899
× 24h × 365 days ×
100
Pr. 896
4
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