Mitsubishi Electric 800 Series Instruction Manual page 297

 Annual power saving amount and power cost savings (Pr.899)
• When the operation time rate [%] (ratio of time in year that the inverter actually drives the motor) is set in Pr.899, the annual
energy saving effect can be estimated.
• When the operation pattern is determined to a certain extent, the estimated value of the annual power saving amount can
be calculated by measuring the power saving in a certain measurement period.
• Refer to the following to set the operation time rate.
1.
Estimate the average time of operation per day [h/day].
2.
Calculate the number of operation days per year [days/year]. (Average number of operation days per month  12
months)
3.
Calculate the annual operation time [h/year] from step 1 and step 2.
Annual operation time (h/year) = average time (h/day) × number of operation days (days/year)
4.
Calculate the operation time rate and set it in Pr.899.
NOTE
• Setting example for operation time rate: When operation is performed about 21h per day for an average 16 operation days
per month, Annual operation time = 21 (h/day)  16 (days/month)  12 months = 4032 (h/year)
Set 46.03% in Pr.899.
• Calculate the annual power saving amount from Pr.899 Operation time rate (estimated value) and the average power
saving monitor.
Annual power saving amount (kWh/year) =
• When the power cost per hour is set in Pr.896 Power unit cost, the annual power cost savings can be monitored.
NOTE
• During regenerative driving, make calculation on the assumption that "power saving = power during commercial power
supply operation (input power = 0)".
Parameters referred to
Pr.3 Base frequency
Pr.52 Operation panel main monitor selection
Pr.158 AM terminal function selection
Pr.54 CA terminal function selection
296
5. PARAMETERS
5.8 (M) Monitor display and monitor output signal
Annual operation time (h/year)
Operation time rate (%) =
24 (h/day) × 365 (days/year)
Operation time rate (%) =
24 (h/day) × 365 (days/year)
Annual power cost saving = annual power saving amount (kWh/year) × Pr.896
page 539
page 284
page 284
× 100(%)
4032 (h/year)
× 100(%) ＝ 46.03%
With Pr.898 = 10 or 9999, average power
saving (kW) during cumulative period
page 274
Pr.899
× 24h × 365 days ×
100