Mitsubishi Electric FR-A700 Series, Technical Manual

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363
PARAMETER
2
P
ARAM
ETE
R
(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.
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.
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 ].
(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 12 months)
3) Calculate the annual operation time [h/year] from 1) and 2).
4) Calculate the operation time rate and set it to [ Pr. 899 ].
Calculate the annual power saving amount from [ Pr.
899 Operation time rate (estimated value) ] and power
saving average value monitor.
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.
In the regeneration mode, make calculation on the
assumption that power saving = power during commercial
power supply operation (input power = 0).
0
10
20
30
40
50
60
70
80
90
100
110
0 10 20 30 40 50 60 70 80 90100110
Ratio of speed to rating [%]
Discharge side
damper control
(fan)
Inlet damper control
(fan)
Valve control
(pump)
Commercial power-supply drive
Power consumption [%]
Power estimated value (kW) during commercial power
supply operation
(kW)
= [Pr. 893]
kW
Power consumption (%) [ Pr. 892 ] (%)
100 100
[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 (day/month) 12 months
= 4032(h/year)
Operation time rate =
4032 (h/year)
100(%)
24 (h/day) 365 (days/year)
= 46.03
Set [
Pr. 899
= 46.03%] .
Annual operation time (h/year)
= average time (h/day) operation days (days/year)
Operation time
rate (%)
=
Annual operation time (h/year)
100
24 (h/day) 365 (days/year)
Annual power saving amount (kWh/year)
=
Power savings average value
during accumulation with
[
Pr. 898 = 10 or 9999
] (kW)
24h 365days
[ Pr.899 ]
100
Annual power saving amount charge
= annual power saving amount (kWh/year) [
Pr. 896
]