Operating Instructions

Chapter 4 – Electrical Installation
Siemens Building Technologies, Inc. 21
Star or Delta Motor Connection
The required supply voltage and method of connection are indicated on the motor rating
plate. In general, larger motors (400/690V) connect in a delta configuration and smaller
motors (230/400V) connect in a star configuration (or wye “Y” configuration). See Figure 16.
MOTOR TERMINALS
U2 V2W2
U1 V1 W1
U2 V2W2
U1 V1 W1
VFD0029R2
Wye "Y"
Figure 16. Delta and Star (Wye, Y) Motor Connections.
External Motor Overload Protection
During operation below nominal speed, the cooling effect of the fans mounted to the motor
shaft is reduced. Therefore, most motors require derating if operated continuously at low
frequencies. To ensure that motors are protected from overheating under these conditions,
mount a PTC temperature sensor to the motor and connect it to the control terminals of the
SED2.
NOTE: To enable the switch-off function, set Motor Temperature Sensor parameter
P0601 to 1 (for PTC thermistor).
14
15
SED2
CONTROL
TERMINALS
VFD0031R1
Figure 17. External Motor Overload Protection.
Control Terminal Connections
NOTES:
1. Use only shielded cables for control cables.
2. Route control cables in separate cable trunks at least 7.8 inches (20 cm) away from
motor and power cables
The control terminals are located on the I/O module. The I/O module is identical for all
models. It is located under the operator panel. See the Access to Control Terminals section
in this manual.