Calculate Power Control Start Point Pressure And Corresponding Flow In Advance - Danfoss D1 Series Service Manual

Service Manual
D1 High Power Open Circuit Pumps Size 65/130/145/193/260
Adjustments

Calculate Power Control Start Point Pressure and Corresponding Flow in Advance

© Danfoss | July 2019
If Power/Torque control is used:
1. Calculate the power control start point pressure according to the formula:
10
Power = P
n
• • Vg •
600 • η
P Power control start point pressure [bar]
n
Pump input speed [rpm]
Vg Pump theoretical displacement [cc]
η
Total efficiency, set at 91.2%
The start point pressure is the point in the Pressure vs Flow performance curve in which the Torque
control becomes active. The PC setting must be higher than this value, otherwise the PC function will
take priority before the MTC function becomes active. If the desired power setting is 90kW, the pump
input speed is 1500 rpm and the pump's theoretical displacement is 193cc, then solve for start point
Pressure:
90 = P
1500 193
• • •
600 • (.912)
Start point Pressure is calculated to be 170bar.
2. Use the average value between the start point Pressure and the Pressure Compensated Control
setting as a reference value; this value must be inside the "TC active" region. For example: Power
control start point Pressure is 170 bar, and the Pressure compensated control setting desired is 320
bar. Use the average value (170+320)/2=245 bar.
3. Calculate corresponding flow by using the following formula:
P • Q
Power [kW] =
600 • η
245 • Q
90 =
600 • (.912)
Q=201 l/min
-3
10 -3
L1527453 | AX00000292en-CN0201 | 35