15.2
Calculations for the Mains Connection
15.2.1
Calculating the Mains-Side Phase Current
The mains-side phase current is required for the following cases:
●
Selecting mains contactor
●
Determining fuses in the mains connection
●
Determining line cross section
●
Selecting other components in the mains connection (mains filter, mains
choke)
Operation Under Rated Conditions
For data on mains contactor, fuses and cross section in operation under rat‐
ed conditions, see technical data of the respective component.
Operation at Partial Load
Operation at partial load can lead to smaller mains contactors, fuses and line
cross sections.
If defined data for operation at partial load are available, the mains-side
phase current can be determined as follows:
1.
Determine motor power
Take power of drive controller-motor combination from Rexroth Indra‐
Size or calculate it.
P
mHa
Mechanical nominal power for main drives (shaft
output) [kW]
M
n
Nominal motor torque [Nm]
n
n
Nominal motor speed [min
-1
]
2.
Determine DC bus power from motor power and efficiency
P
DC
Required DC bus continuous power [W]
M
rms
Effective torque in Nm
n
m
Average speed in min
-1
k
Factor for motor and controller efficiency = 1.25
3.
Add powers of all axes at common DC bus and put them into relation to
rated power of supply unit
⇒ Partial load of P
DC_cont
is available
4.
Determine power factor TPF for partial load (TPF = Total Power Factor)
For the value TPF at rated power and TPF
10
(at 10% of rated power),
see technical data (mains voltage) of the component.
5.
Calculate mains connected load
S
LN
Mains connected load [VA]
P
DC
DC bus continuous power [W]
Bosch Rexroth AG
DOK-INDRV*-SYSTEM*****-PR06-EN-P
Rexroth IndraDrive Drive Systems with HMV01/02 HMS01/02, HMD01, HCS02/03
260/309
Calculations
