Danfoss VLT HVAC Drive FC 102 Programming Manual page 185

Parameter Descriptions
The difference between the reference power at fixed speed and the actual power yielded with speed control represent the
actual saving.
As value for the fixed speed case, the rated motor size (kW) is multiplied with a factor (set in %) representing the power
produced at fixed speed. The difference between this reference power and the actual power is accumulated and stored. The
difference in energy can be read in parameter 23-83 Energy Savings.
The accumulated value for the difference in power consumption is multiplied with the energy cost in local currency and the
investment is subtracted. This calculation for cost savings can also be read in parameter 23-84 Cost Savings.
Cost Savings =
t
∑ Rated Motor Power ∗ Power Reference Factor
t = 0
− Actual Power Consumption × Energy Cost
− Investment Cost
Break even (payback) occurs when the value read in the parameter turns from negative to positive.
It is not possible to reset the energy savings counter, but the counter can be stopped any time by setting
parameter 23-80 Power Reference Factor to 0.
Parameter for settings
Rated motor power
Power reference factor in %
Energy cost per kWh
Investment
Table 3.26 Parameter Overview
23-80 Power Reference Factor
Range: Function:
100 [0 - Set the percentage of the rated motor size (set
% 100 %] in parameter 1-20 Motor Power [kW] or
*
parameter 1-21 Motor Power [HP]), which should
represent the average power yielded at the time
running with fixed speed (before upgrade with
variable speed control).
Must be set to a value different from zero to
start counting.
23-81 Energy Cost
Range: Function:
1 [0 - 999999.99 ] Set the actual cost for a kWh in local
*
currency. If the energy cost is changed
later on, it impacts the calculation for the
entire period.
23-82 Investment
Range: Function:
0 [0 - Set the value of the investment spent on
*
999999999 ] upgrading the plant with speed control, in
same currency as used in
parameter 23-81 Energy Cost.
MG11CE02
Programming Guide
Parameter 1-20 Motor Power [kW]
Parameter 23-80 Power Reference
Factor
Parameter 23-81 Energy Cost
Parameter 23-82 Investment
Danfoss A/S © 03/2015 All rights reserved.
Parameters for readout
Energy savings
Actual power
Cost savings
23-83 Energy Savings
Range: Function:
0 kWh [0 - 0 This parameter allows a readout of the
*
kWh] accumulated difference between the reference
power and the actual output power.
If motor size is set in hp
(parameter 1-21 Motor Power [HP]), the
equivalent kW value is used for the energy
savings.
23-84 Cost Savings
Range: Function:
0 [0 - 2147483647 ] This parameter allows a readout of the
*
calculation based on the above equation
(in local currency).
Parameter 23-83 Energy Savings
Parameter 16-10 Power [kW],
parameter 16-11 Power [hp]
Parameter 23-84 Cost Savings
183
3 3