9307391
Ind Mod. 33119
Thermal Overload Relay
Current transformer operated
Fig. 2
Fig. 1
RTD180
Operatinginstructions
WARNING: Hazard of electrical shock. Installation and
maintenance by qualified personnel only.
Isolate before servicing. Follow the operating instructions.
Protection degreeIP00withlinks,IP10withMR3terminalboxandIP20
without links.
Specifications are subject to change without notice
Main Connection size
60-90A Up to 50mm2(1AWG)
80-120A Up to 120mm2(AWG4/0) with links for
connection as indipendent unit or to GH15NT
and GH15PT contactors
With terminal box MR3-AD (optional) for
connection with cable of 16-120mm2
(AWG5 -4/0) section
Auxiliary Connection size
Flexible or stranded cable 2 x 0,75-
2,5mm2(AWG 18-14)
Flexible with multicore cable end
2 x 0,5-1,5mm2 (AWG20-16)
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
120-180A
2.1.Main connection
Torque:M8 screws = 17Nm (150 lb.in)
For current up to 120A the current transformer unit permits the use of
conductors through the central core hole for each phase connection.
For higher current suitable connecting links are available.
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 hundredth of
primary current.
Example: rated load current 120A
setting of relay 1.2A
Three phase wiring diagrams
Single phase wiring diagrams
Contactor
O/L
Contactor
O/L
