Danfoss VLT HVAC Basic Drive FC 100 Series Programming Manual page 11

Introduction
plus
VVC
If compared with standard voltage/frequency ratio control,
plus
Voltage Vector Control (VVC
and the stability, both when the speed reference is
changed and in relation to the load torque.
Power Factor
The power factor is the relation between I
3 x U x I 1 cos ϕ
Power factor =
x U x I RMS
3
The power factor for 3-phase control:
I 1
I 1 x cos ϕ1
= = since cos ϕ1 = 1
I RMS I RMS
The power factor indicates to what extent the adjustable
frequency drive imposes a load on the line power supply.
The lower the power factor, the higher the I
same kW [hp] performance.
I 1 2 + I 5 2 + I 7 2 + .. + I n 2
I RMS =
In addition, a high power factor indicates that the different
harmonic currents are low.
The built-in DC coils in the adjustable frequency drive
produce a high power factor, which minimizes the
imposed load on the line power supply.
1.1.6 Safety Precautions
WARNING
The voltage of the adjustable frequency drive is dangerous
whenever connected to line power. Incorrect installation of
the motor, adjustable frequency drive or serial communi-
cation bus may cause death, serious personal injury or
damage to the equipment. Consequently, the instructions
in this manual, as well as national and local rules and
safety regulations, must be complied with.
Safety Regulations
1. The line power supply to the adjustable
frequency drive must be disconnected whenever
repair work is to be carried out. Make sure that
the line power supply has been disconnected and
that the necessary time has elapsed before
removing motor and line power supply plugs.
2. The [OFF] key on the control panel of the
adjustable frequency drive does not disconnect
the line power supply and consequently it must
not be used as a safety switch.
3. The equipment must be properly grounded, the
user must be protected against supply voltage
®
VLT HVAC Basic Drive Programming Guide
) improves the dynamics
and I .
1 RMS
for the
RMS
®
MG18B222 - VLT is a registered Danfoss trademark
and the motor must be protected against
overload in accordance with applicable national
and local regulations.
4. The ground leakage current exceeds 3.5 mA.
5. Protection against motor overload is not included
in the factory setting. If this function is desired,
set 1-90 Motor Thermal Protection to data value [4]
ETR trip 1 or data value [3] ETR warning 1.
6. Do not remove the plugs for the motor and line
power supply while the adjustable frequency
drive is connected to line power. Make sure that
the line power supply has been disconnected and
that the necessary time has elapsed before
removing motor and line power plugs.
7. Please note that the adjustable frequency drive
has more voltage sources than L1, L2 and L3,
when load sharing (linking of DC intermediate
circuit) or external 24 V DC are installed. Make
sure that all voltage sources have been discon-
nected and that the necessary time has elapsed
before commencing repair work.
1.1.7 Safety Precautions - Continued
Warning against unintended start
1. The motor can be brought to a stop by means of
digital commands, bus commands, references or
a local stop, while the adjustable frequency drive
is connected to line power. If personal safety
considerations (e.g., risk of personal injury caused
by contact with moving machine parts following
an unintentional start) make it necessary to
ensure that no unintended start occurs, these
stop functions are not sufficient. In such cases,
the line power supply must be disconnected.
2. The motor may start while setting the
parameters. If this means that personal safety
may be compromised (e.g., personal injury caused
by contact with moving machine parts), motor
starting must be prevented, for instance by
secure disconnection of the motor connection.
3. A motor that has been stopped with the line
power supply connected, may start if faults occur
in the electronics of the adjustable frequency
drive, through temporary overload or if a fault in
the power supply grid or motor connection is
remedied. If unintended start must be prevented
for personal safety reasons (e.g., risk of injury
caused by contact with moving machine parts),
the normal stop functions of the adjustable
frequency drive are not sufficient.
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