9307392
CD33120
Thermal Overload Relay
Current transformer operated
Fig. 2
Fig. 1
Operatinginstructions
RTD320
WARNING: Hazard of electrical shock. Installation and
maintenance by qualified personnel only.
Isolate before servicing. Follow the operating instructions.
Protection degree IP00
Specifications are subject to change without notice
Main Connection size
Up to 185 mm2 (350MCM)
Auxiliary Connection size
Flexible or stranded cable
2 x 0,75-2,5 mm2 (AWG 18-14)
Flexible with multicore cable end
2 x 0,5-1,5 mm2 (AWG 20-16)
1. Configuration
The current transformer overload relay unit is supplied as independetly
mounted assembly. It is provided with four fixings for panel mounting,
see fig.3.
The thermal overload relay is a factory connected unit, being permanently
sited on top of the 3 phase current transformer assembly mouldings.
Mounting position: any vertical plane orientation within ±30°.
The relay is suitable only for a.c. current 50-60Hz.
Trip class to IEC 60947-4-1: class 10A.
2. Cabling
2.1.Main connection
Torque:M10 screws = 35 Nm (275 lb.in)
Suitable connecting links to contactor are supplied.
For single phase loads the three main circuits must be series connected.
2.2.Control connection
Torque: M3.5 screws =1-1.3Nm. (7 lb.in)
Using correctly size cable, connect the operating coil of the associated
contactor in series with the NC contact of the relay i.e. 95-96.
If a signalling device has to be energized when the relay trips, connect it in
series with the NO contact, i.e. 97-98.
The NC circuit is electrically separate from the NO circuit up to 440V
(150 V AC for UL standard).
3. Setting to full load current of the motor
The relay is set to the full load current of the motor (primary current) by
rotating the adjustment dial .1 (fig.2) until the arrow head correspond to the
value of current.
The secondary current for the adjustment of the relay is one eightieth of
primary current.
Example: rated load current 240A
setting of relay 3A
Three phase wiring diagrams
Single phase wiring diagrams
Contactor
O/L
O/L
Contactor
+
