Connection diagrams / Junction box
3 phase connection
Electrical connection: Please refer to the data plate supplied for the correct voltage, amperage and other important
data. Depending on the speciﬁcation, it may be possible to connect the motor in star Y or delta or both.
If in doubt please refer to BDL.
Drum motor with built-in reverse lock: Check correct rotation before starting! The motor will turn in accordance with
the arrow sign ﬁxed to the end housing if the phases are in correct order (R-S-T) and wired to U1-V1-W1 as shown in
the diagram. To check the correct order of the phases use a suitable measuring instrument. Wrong connection may
cause serious damage to the reverse lock at ﬁrst operation.
Motor protection: All drum motors from type 110 are equipped with winding protection contacts (TF). The TF is
closed under normal running conditions. However, if the motor overheats, the TF will open at a preset temperature
(depending on the isolation class) before damage to the motor can occur. The TF will automatically re-set when the
motor has cooled down. After cooling, the motor has to be re-started.
It is important that the TF is connected to a suitable relay or contactor which ensures disconnection of the power
supply to the motor when tripped.
3 phase connection in star (Y) or delta (∆) with winding protection (TF)
Star (Y) Delta (∆)
3 phase connection with electromagnetic brake (EB) and winding protection (TF)
Wiring diagram for 3-phase drum motor with winding pro-
tection (TF) and electromagnetic brake. When supplied in
star Y, the starpoint is at terminal X-Y-Z.
Drum motors with electromagnetic brake can run (and stop)
in both directions. The electromagnetic brake is mounted
inside the motor. It is a single disc spring pressure brake,
which in standard construction must be connected to a 105
V DC rectiﬁer (supplied) which should be wired to a 1 x 230
V/50 Hz (A.C.) supply.
Do not use position 3 & 4 on the rectiﬁer as this could damage
the brake. It is strongly recommended to position the rectiﬁer
within 2 meters of the brake in order to prevent voltage tran-
sience and or electrical interference through the cable. If the
distance between rectiﬁer and brake is more than 2 meters, a
screened cable 0.75 mm sqr. should be installed together with
a varistor ﬁtted as close to the brake as possible to prevent
interference from electrical transience and spikes. The control
relay or contactor for the drum motor must ensure that the brake is opened/released when the motor is started. If the
brake is used for a decline conveyor, do not connect the rectiﬁer to the star point of the motor but use a seperate 1
56 phase 230V 50 Hz supply.
3 phase connection with two speeds in "Dahlander"
Low speed High speed
Steinmetz connection for 3 phase motor connected to single phase supply
Note: When connecting 3 phase 230 V motors in steinmetz, the starting torque will be reduced to 60-80% and the
running torque to 70% of the rated torque.
Delta (∆) Delta (∆)
Steinmetz connection / normal rotation Steinmetz connection / change rotation