Motor Cables; Motor Thermal Protection; Earth Connection; Load Sharing - Danfoss AKD 2800 Quick Setup Manual

Motor cables

See Technical data for correct dimensioning of motor
cable cross-section and length. Always comply with
national and local regulations on cable cross-section.
NB!:
If an unscreened/unarmoured cable is used,
some EMC requirements are not complied with.
If the EMC specifications regarding emission are
to be complied with, the motor cable must be
screened/armoured, unless otherwise stated for the
RFI filter in question. It is important to keep the motor
cable as short as possible so as to reduce the noise
level and leakage currents to a minimum. The motor
cable screen must be connected to the metal cabinet
of the frequency converter and to the metal cabinet of
the motor. The screen connections are to be made
with the biggest possible surface area (cable clamp).
This is enabled by different installation devices in
different frequency converters. Mounting with twisted
screen ends (pigtails) is to be avoided, since these
spoil the screening effect at high frequencies. If it
is necessary to break the screen to install a motor
isolator or motor relay, the screen must be continued
at the lowest possible HF impedance.

Motor thermal protection

The electronic thermal relay in UL-approved frequency
converters has received the UL-approval for single
motor protection, when parameter 128 Motor thermal
protection has been set for ETR Trip and parameter
105 Motor current, I has been programmed to
M, N
the rated motor current (see motor nameplate).

Earth connection

As leak current to the earth is higher than 3.5 mA, the
frequency converter must always be earthed according
to prevailing national and local regulations. To
guarantee that the earth cable has a good mechanical
connection to terminal 95, the cable cross section
2
must be at least 10 mm
that are terminated separately. To increase safety
you can install an RCD (Residual Current Device),
which guarantees that the frequency converter trips
when leak current becomes too high. See also
RCD Application Note MN.90.GX.02.

Load sharing

Load sharing provides the facility to connect several
frequency converters' DC intermediate circuits.
54
or 2 rated earth wires
AKD 2800
This requires that the installation is extended using
extra fuses and AC coils (see drawing below).
For load sharing parameter 400 Brake function
must be set to Load sharing [5].
Use 6.3 mm Faston Plugs for DC (Load Sharing).
Contact Danfoss or see instructions no. MI.50.NX.02
for further information.
No. 88 89 Loadsharing
- +
Note that voltage levels of up to 850 V DC
may occur between terminals 88 and 89.

Tightening Torque, Power Terminals

Power and earth terminals must be tightened
with the following torques:
AKD Terminals
2803- Power mains brake
Earth
2875
2880- Power mains brake
Earth
2882

Access to control terminals

All terminals to the control cables are located
underneath the protective plate on the front of the
frequency converter. Remove the protective plate
by pulling it downwards (see drawing).
Torque [Nm]
0.5-0.6
2-3
1.2-1.5
2-3
MG.28.H2.02 -