Specifications

5.4.9 Direction of Motor Rotation
The default setting is clockwise rotation with the frequency
converter output connected as follows.
Terminal 96 connected to U-phase
Terminal 97 connected to V-phase
Terminal 98 connected to W-phase
The direction of motor rotation is changed by switching 2
motor phases.
Motor rotation check can be performed using P-08 Motor
Rotation Check and following the steps shown in the
display.
96 97
U V
96 97 98
U VW
98
W
130HA036.10
Illustration 5.100 Changing Motor Rotation
The electronic thermal relay in the frequency converter has
received UL-approval for single motor protection, when
1-90 Motor Thermal Protectionis set for ETR Trip and
1-24 Motor Current is set to the rated motor current (see
the motor name plate).
For thermal motor protection it is also possible to use the
MCB 112 PTC Thermistor Card option. This card provides
ATEX certificate to protect motors in explosion hazardous
areas, Zone 1/21 and Zone 2/22. When 1-90 Motor Thermal
Protection is set to [20] ATEX ETR is combined with the use
of MCB 112, it is possible to control an Ex-e motor in
explosion hazardous areas. Consult the programming
guide for details on how to set up the frequency converter
for safe operation of Ex-e motors.
5.4.10 Motor Insulation
For motor cable lengths ≤ the maximum cable length
listed in 8 General Specifications and Troubleshooting, the
recommended motor insulation ratings are in Table 5.81.
The peak voltage can be up to twice the DC link voltage,
2.8 times the mains voltage, due to transmission line
effects in the motor cable. If a motor has a lower
insulation rating, use a dU/dt or sine wave filter.
Nominal Mains Voltage Motor Insulation
U
N
≤ 420 V
Standard U
LL
= 1300 V
420 V < U
N
≤ 500 V Reinforced U
LL
= 1600 V
500 V < U
N
≤ 600 V Reinforced U
LL
= 1800 V
600 V < U
N
≤ 690 V Reinforced U
LL
= 2000 V
Table 5.81 Motor Insulation at Various Nominal Mains Voltages
5.4.11 Motor Bearing Currents
For motors with a rating 110 kW or higher operating via
frequency converters use NDE (Non-Drive End) insulated
bearings to eliminate circulating bearing currents due to
the physical size of the motor. To minimize DE (Drive End)
bearing and shaft currents, proper grounding of the
frequency converter, motor, driven machine, and motor to
the driven machine is required. Although failure due to
bearing currents is rare, if it occurs, use the following
mitigation strategies.
Standard mitigation strategies
•
Use an insulated bearing
•
Apply rigorous installation procedures
Ensure the motor and load motor are aligned
Strictly follow the EMC Installation guideline
Reinforce the PE so the high frequency
impedance is lower in the PE than the input
power leads
Provide a good high frequency connection
between the motor and the frequency converter
by screened cable, which has a 360° connection
in the motor and frequency converter
How to Install VLT® HVAC Drive FC 102 Design Guide
148 MG16C102 - Rev. 2013-08-20
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