Danfoss Turbocor TT-300 User Manual

Service Monitor User Manual
Danfoss Turbocor Compressors Inc. A-1
ECD-00007M Rev. 1
Appendix A: Determination of Actual Power Setting
The BMC\CC holds four variables in the EPROM that
determine the input power capability of the compressor
based on the model number of the compressor. These four
variables define the straight-line equation for the maximum
referred power (y=mx+c) as a function of total flange to
flange pressure ratio, see graph below. The referred power
is the power absorbed at the reference pressure and
temperature.
Next the power-reset factor may be calculated from the
absolute suction pressure (referred power).
To obtain the actual maximum power input, the referred
power input is multiplied by the power reset factor
The next step is to calculate the percentage of the maximum
power that is required based on the analogue input voltage
level, modbus set demand or chiller control supplied
demand.
Analog Input Mode Example:
Calculate the actual 3ph power set point for a 75ton
(TT300W-75TR-460-480V) compressor running with a
suction pressure of 340 kPa, a compression ratio of 2.80 and
an input voltage level of 6.50 VDC.
Recall that for analogue input mode, the input voltage range
is 0-10VDC, with a deadband of 2VDC.
Thus, the demand % for a 6.50 VDC input is:
%demand = (6.5-2)/(10-2) = 0.562 or 56.2%
For a reference pressure of 356kPa at 283ºK:
The referred power is determined to be:
PWR
ref
= 24.783*2.80-14.06 = 55.32 kW
The actual maximum power is:
PWRmax= 55.32 * (340 / 356) = 52.83 kW
The desired 3 phase power input is then :
Desired power = 52.83 * .562 = 29.69 kW
ModBus Network Input Mode Example:
Calculate the actual 3ph power set point for a 75ton
(TT300W-75TR-460-480V) compressor running with a
suction pressure of 340 kPa, a compression ratio of 2.80 and
a input voltage level of 6.50 VDC.
The demand % for a 6.50 VDC input is:
Recall that in Modbus network input mode, the demand is
manually set through the Monitor program.
In this case, the demand is set to 56.2%.

Danfoss Turbocor TT-300 Specifications

General

Brand	Danfoss
Model	Turbocor TT-300
Category	Air Compressor
Language	English