GE MVAJ Trip Relay: Protection and Control Core

MVAJ 05: Regardless of high or low load configuration, the load is instantly cut off or reduced to energy-saving level after the action.

MVAJ 10/MVAJ 20: In high load configuration, the load will remain at about 40-60ms (with a power consumption of about 100W) after the action, and then be cut off or reduced to energy-saving level. This brief delay ensures that other components connected in series with the relay coil, such as MVAX 11 monitoring relay, MCAA relay, etc., can reliably operate.

3. Action time and contact jitter

For tripping applications, speed is crucial.

Standard trip type (with manual reset flag): The action time of MVAJ 05 and MVAJ 10 is less than 8ms, and MVAJ 20 is less than 10ms.

Control type (with following flag): If the following flag is selected, the action time will increase to about 15ms, so it is generally not recommended for trip circuits with extremely high speed requirements.

Contact shaking: The contact shaking time does not exceed 1ms, ensuring crisp and clean operation and reducing the erosion of the contact by the arc.

4. 2.5-second delay self resetting relay (MVAJ 102)

This is a model specifically designed for specific connected applications. A typical scenario is the mutual tripping of large transformers: when a serious internal fault occurs on the high voltage side, the high voltage side circuit breaker quickly trips, but the low voltage side circuit breaker may be protected and return due to the fault current being cut off, resulting in unreliable tripping of the low voltage side circuit breaker.

After MVAJ 102 is protected (such as gas, differential), its contacts close. Even if the start signal disappears quickly (briefly closes), the timer inside MVAJ 102 starts counting, and the contacts will remain closed for 2.5 seconds, ensuring that the low-voltage side circuit breaker has enough time to complete the trip. If the start signal persists, the relay will remain in action until the signal disappears and then reset with a delay of 2.5 seconds.

User configurable features and external connections

The high flexibility of the MVAJ series is reflected in the ability to change relay characteristics through external connectors without disassembling internal circuits.

1. Load configuration selection

Relay model: High load mode (default), Low load mode (with external connections removed)

MVAJ 051, 053, 054, 055 instantaneous load shedding instantaneous load shedding

MVAJ 101, 103, 104, 105, 203, 204, 205 load shedding after 40-60ms delay instantaneous load shedding

MVAJ 102 is fixed in high load mode-

2. Reset suppression function

For electric reset and manual/electric reset models (MVAJ 104/105/2004/205), the reset suppression function can be enabled by connecting terminals 21 and 23. This function ensures that the reset circuit is electrically locked when the operating circuit is excited, preventing the relay from oscillating (quick action reset action) when both the operating and reset commands are present, thereby protecting the relay and external contacts.

Detailed technical specifications

1. Rated voltage and operating range

Rated voltage (Vx) Operating range (V)

24/27 14.4 – 32.4

30/34 18.0 – 40.8

48/54 28.8 – 64.8

110/125 66 – 150

220/250 132 – 300

2. Power consumption and minimum operating current

Model: Power consumption at maximum rated voltage (W), minimum operating current (mA), minimum reset current (mA)

MVAJ 05 80/150* <40 >25/50*

MVAJ 10 50/150* <40 >25/50*

MVAJ 20 50/150* <80 >25/50*

*Low load/high load configuration

3. Contact capacity

Short time connection and load (3 seconds):

Communication: 7500 VA, maximum value of 30A or 300V

DC: 7500 W, maximum value 30A or 300V

Continuous connection and carrying:

Communication: 1250 VA, maximum 5A or 300V

DC: 1250 W, maximum value 5A or 300V

Breaking ability:

Communication: 1250 VA, maximum 5A or 300V

DC: 80W (resistive)/40W (inductive L/R=0.04s), maximum value 5A or 300V

4. Durability

Load contact: 10000 operations (minimum)

No load contact: 100000 operations (minimum)

5. Reset time

Self resetting relay: MVAJ 051 (low load, and 24-54V high load) MVAJ 101：20ms

2.5 second delay self reset: approximately 2.5 seconds

Electric reset:<15ms

Instructions and Signs

1. Manual reset flag

All MVAJ trip relays come standard with a manual reset flag. When the relay is activated, the flag drops. Even if the auxiliary power supply disappears, the flag remains in the active position, indicating that a trip event has occurred. The reset flag can be manually reset through the reset lever on the panel.

2. Follow the sign

Optional follow-up symbol can be installed, which will reflect the current status of the relay in real time (falling when activated and lifting when reset). Mainly used for controlling functions and facilitating on-site observation of equipment status. But as mentioned earlier, it will increase the action time.

Mechanical Structure and Installation

The MVAJ relay adopts the Midos system standardized chassis, which facilitates installation and wiring on the control panel.

MVAJ 05/MVAJ 10: Adopting a Size 2 casing.

MVAJ 20: Adopting a Size 4 casing.

All wiring is completed through the terminal block at the rear of the housing, and the logical relationship between the internal circuit and external wiring needs to refer to the specific model's wiring diagram (such as the MVAJ 21 typical internal wiring diagram provided in the manual).