3RV2 circuit breaker is a compact current limiting motor starting protection circuit breaker, which can be used for opening and closing protection of three-phase induction motors (power up to 18.5kW at 400V AC) and other loads (rated current up to 40A).
Specification Notes
3RV2 Circuit Breaker includes 2 sizes:
· 500 specifications -45mm wide,
Maximum rated current 16A, AC 400 V for induction motor maximum 7.5 kW.
· 50 gauge -45mm wide,
Maximum rated current 40A, AC 400 V for induction motor maximum 18.5 kW.
Application
Operating conditions
The 3RV2 circuit breaker is suitable for any climate and is used in the normal operating environment of the enclosed space (for example, no dust, no corrosive gas or harmful gas). Suitable protective covers are required for installation in dusty and wet areas.

The 3RV2 circuit breaker can be wired from the top or bottom.

Refer to the specific technical data and tripping characteristic curve of this chapter for the allowable ambient temperature, maximum breaking capacity, tripping action current and other conditions of the circuit breaker.

3RV2 circuit breakers can be used in IT systems (IT networks), but different short-circuit breaking capabilities in IT systems should be considered.

Even the same rated power of the motor, due to the instantaneous peak current, the working current, starting current and current peak is also different. Therefore, the motor rating in the selection table can only represent the guiding data, and the actual rating data and starting data of the motor are very important for selecting the appropriate circuit breaker. This principle also applies to circuit breakers for transformer protection.

Application category
The 3RV2 circuit breaker can be used:
· Motor protection
· System protection
· Starter combination short-circuit protection
· Transformer protection
· As the main switch and emergency stop switch
• IT systems (IT networks)
· DC circuit
Explosion-proof applications (ATEX)

General Data
Design

Terminal
3RV2 circuit breakers can be provided with screw, spring or ring terminals, according to different application needs can flexibly choose the appropriate wiring type.

Installation
The 3RV2 circuit breaker can be snapped onto a standard 35 mm rail.
The 500 and s0 specifications can be used with 3RV29 28-OB plug-in plate for direct screw fixing on the bottom plate.

Function
release
The 3RV2 motor protection circuit breaker is equipped with an inverse time bimetallic thermal overload release and an instantaneous overcurrent release (electromagnetic short circuit release).
The thermal overload trip current can be adjusted according to the load current. In order to avoid failure when starting the motor, the short-circuit trip current shall be fixed at 1 3 times the rated current of the circuit breaker.
In order to prevent tripping caused by high transformer inrush current, the circuit breaker used for transformer protection on the power supply side is set for short-circuit tripping current at 20 times the rated current of the transformer.

tripping level
The tripping level of the thermal overload release is based on the tripping time at 7.2 times the cold operating current (tA)(taken from the IEC60947-4 standard):
'CLASS 10A:2s·CLASS 10:4s·CLASS 20:6s·CLASS 30:9sThe motor protection circuit breaker must trip within this time frame.

Operating mechanism
The 3RV2 circuit breaker works by a rotary operating mechanism. When the circuit breaker is tripped, the rotary operating mechanism will switch to the "tripped" position for indication. Before the circuit breaker is closed again, the rotary operating mechanism must be manually reset to the "0" position to prevent the circuit breaker from being closed by mistake before the fault is eliminated, after which the circuit breaker can be placed in the "l" position.
All rotary operating mechanisms can be locked in the "0" position with a padlock (the diameter of the padlock hook ring is 3.5mm ~ 4.5mm).
The isolation function of the 3RV2 circuit breaker complies with standard IEC 60947-2.

Configuration
Prevent accidental tripping
Since the motor protection circuit breaker has the function of phase loss protection, make sure that all three phases have current through the connection.

Short circuit protection
In the event of a short circuit, the short circuit trip of the 3RV2 circuit breaker isolates the faulty load feeder from the power supply, thereby preventing further losses.
Most models of 3RV2 circuit breakers have a rated limit short-circuit breaking capacity of more than 55 kA under AC 400V, and the short-circuit protection reliability is extremely high, because such a high short-circuit current is usually not encountered.

Motor protection
The tripping characteristics of 3RV20 motor protection circuit breaker are mainly designed to protect three-phase induction motors.
The rated current/n of the protection motor can be adjusted in the setting knob. The short-circuit trip current shall be set to 1 3 times the rated current of the motor protection circuit breaker. In this way, the motor can be started without fault tripping and can be properly protected.
If there is a phase failure and an overcurrent due to a phase line fault, the lack of phase protection of the motor protection circuit breaker ensures timely tripping.
Motor protection circuit breakers with thermal overload release shall be designed for trip class 10.

System Protection
The 3RV20 motor protection circuit breaker for motor protection can also be used for system protection.
In order to prevent premature tripping due to lack of phase protection, the protection object must be a three-phase symmetrical load. If it is a single-phase load, the circuit must be connected in series.

Short-circuit protection of starting combination
3RV23 circuit breaker can be used for short circuit protection of starting combination by combining with contactor and overload relay.
Like the motor protection circuit breaker for motor protection, the 3RV23 circuit breaker is also equipped with a torque trip, and its trip value is fixedly set at 1 3 times the rated current of the circuit breaker, without overload trip.
Once an overload occurs, the overload relay triggers the contactor to open and the circuit breaker remains closed. The circuit breaker will trip only if a short circuit occurs in the feeder.
Since the circuit breaker used for the starting combination cannot protect the motor alone and cannot prevent overload by itself, it must be used in conjunction with the overload relay.

Transformer protection
When the control transformer is protected on the power supply side, the instantaneous current generated when the transformer is switched on often causes a false tripping of the protection mechanism.
Therefore, the short-circuit trip value of 3RV24 circuit breaker used to protect the transformer is set at 20 times the rated current value, so it can be used to protect the transformer whose surge peak current is 30 times the rated current on the power supply side.
Control transformers with low inrush current do not require this type of circuit breaker, and the 3RV20 motor protection circuit breaker for motor protection can be used.

Main switch and emergency stop switch
The 3RV2 circuit breaker has an isolation function in accordance with IEC 60947-2 and can be used as a main switch and an emergency stop switch.