AutomationDirect RTD320 Operating Instructions

Thermal Overload Relay
Current transformer operated
Fig. 1

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

Main Connection size
Up to 185 mm
Auxiliary Connection size
Flexible or stranded cable
2 x 0,75-2,5 mm
Flexible with multicore cable end
2 x 0,5-1,5 mm

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
Specifications are subject to change without notice
WARNING:
Hazard of electrical shock. Installation and
maintenance by qualified personnel only.
Isolate before servicing. Follow the operating instructions.
Protection degree IP00
2 (350MCM)
2
(AWG 18-14)
2
(AWG 20-16)
3A
RTD320
Operating instructions
Fig. 2
Three phase wiring
Single phase wiring
9307392
CD33120
diagrams
Contactor
O/L
diagrams
Contactor
O/L