Mitsubishi Electric FR-A700 Technical Manual page 329

(5) Power estimated value of commercial
power supply operation [Pr. 892, Pr. 893,
Pr. 894]
Select the commercial power supply operation
pattern from among the four patterns of discharge
damper control (fan), inlet damper control (fan), valve
control (pump) and commercial power supply drive,
and set it to [Pr. 894 Control selection during commercial
power-supply operation] .
Set motor capacity (pump capacity) in [Pr. 893 Energy
saving monitor reference (motor capacity)].
The power consumption rate (%) during commercial
power supply operation is estimated from the
operation pattern and the ratio of speed to rating
(current output frequency/[Pr. 3 Base frequency]) in the
following chart.
Commercial power-supply drive
110
100
Discharge side
90
damper control
(fan)
80
70
60
50
Inlet damper control
40
(fan)
30
20
10
0
0 10 20 30 40 50 60 70 80 90100110
Ratio of speed to rating [%]
From the motor capacity set in [Pr. 893] and [Pr. 892
Load factor] , the power estimated value (kW) during
commercial power supply operation is found by the
following formula.
Power estimated value (kW) during commercial power
supply operation
Power consumption (%)
= [Pr. 893]
kW
Since the speed does not increase above the power
supply frequency in commercial power supply
operation, it becomes constant when the output
frequency rises to or above [Pr. 3 Base frequency].
Valve control
(pump)
(kW)
[Pr. 892] (%)
100 100
(6) Annual power saving amount, power
charge [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 estimated.
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) Estimate the average time [h/day] of operation in a day.
2) Find the annual operation days [days/year]. (Monthly
average operation days
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
Annual operation time (h/year)
=
rate (%)
[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
= 21 (h/day)
time
= 4032(h/year)
Operation time rate =
Set [Pr. 899 = 46.03%] .
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)
Power savings average value
= during accumulation with
[Pr. 898 = 10 or 9999] (kW)
The annual power saving charge can be monitored by setting
the power charge per hour in [Pr. 896 Power unit cost].
Calculate the annual power saving charge in the following
method.
Annual power saving amount charge
= annual power saving amount (kWh/year) [Pr. 896]
In the regeneration mode, make calculation on the
assumption that power saving = power during commercial
power supply operation (input power = 0).
363
PARAMETER
12 months)
operation days (days/year)
24 (h/day) 365 (days/year)
16 (day/month) 12 months
4032 (h/year)
24 (h/day) 365 (days/year)
= 46.03
24h 365days
100
2
100(%)
[Pr.899]
100