Schneider TeSys GV5/GV6 Motor Circuit Breaker Operation and Protection Guide

Schneider TeSys GV5/GV6 Motor Circuit Breaker Operation and Protection Guide

In modern industrial automation systems, reliable protection of motor circuits is the core link to ensure production continuity and equipment safety. Schneider Electric's TeSys Giga series GV5 and GV6 motor circuit breakers (IEC standard) and manual motor protectors (UL/CSA standard) provide a complete overload, short circuit, and phase loss protection solution for high-power motors ranging from 150A to 500A. This article is based on the technical documentation of this series of devices, and writes a professional technical guide for on-site engineers from four dimensions: actual operation, protection function settings, common fault reset, and auxiliary accessory application. Whether you are debugging equipment for the first time or need to quickly troubleshoot, this article can provide clear step-by-step references.

Equipment Overview and Model Identification

1.1 Framework and Current Range

The TeSys Giga series is divided into two frameworks:

GV5 framework: rated current 150A, 220A

GV6 framework: rated current 320A, 500A

Both are suitable for AC power systems up to 690Vac and offer three trip levels of 5, 10, and 20 to meet the needs of motors with different starting characteristics.

1.2 Interpretation of Model Code

The commercial reference number of each device contains key information. Taking GV5P 220H as an example:

GV5 → Framework is GV5

P → Provide overload and short circuit protection

220 → Rated current 220A

H → Breaking capacity (70kA at 415Vac)

Different suffixes (F/H) correspond to different breaking capacities, for example, at 400/415Vac, GV5P150F is 36kA, while GV5P150H is 70kA. When selecting, it is necessary to match correctly according to the system short-circuit current level.

1.3 Compliance with standards

This series of products complies with IEC/EN 60947-2 (circuit breakers) and IEC/EN 60947-4-1 (motor protection circuit breakers) standards, as well as UL 60947-4-1 and CSA C22.2 No.60947-4-1, and can be used in industrial environments worldwide.

Daily operation and switch reset

2.1 Local operation of directly rotating the handle

Standard equipment is equipped with a direct rotating handle:

Close (ON): Rotate the handle clockwise to position I

Turn on (OFF): Rotate counterclockwise to the O position

The handle color is divided into black (standard application) and red on the yellow panel (machine control application), the latter being used for safety scenarios such as emergency shutdown.

2.2 Reset process after electrical failure

When the device trips due to overload, short circuit, or phase loss, the handle will move to the Trip position (between O and I). The correct reset steps are as follows:

Isolation power supply: Before inspecting downstream equipment, it is necessary to cut off the power supply from the upper level.

Find the cause of the fault: Check whether there is a short circuit, overload, or insulation damage in the motor, cable, contactor, etc.

Repair downstream equipment: replace damaged parts if necessary and conduct insulation testing.

Reset device: Turn the handle counterclockwise from Trip to the O (OFF) position.

Close again: Rotate the handle clockwise to the I (ON) position.

Key reminder: Simply resetting cannot eliminate the root cause of the fault. If the downstream issue is not fixed, closing it again may result in equipment damage or personal injury.

2.3 Push to Trip testing

Regular testing of the trip mechanism can verify whether the protection function is normal. Operation steps:

Close the device (position I).

Press the Push to trip button on the front panel. The equipment should trip immediately and the handle should be moved to the Trip position.

Rotate counterclockwise to position O, then clockwise back to position I to complete the reset.

Caution: This test will actually cut off the load, which may cause unnecessary alarms or backup power switching. Therefore, it should only be performed by qualified personnel during the maintenance window period.

2.4 Operation of Extending the Rotating Handle

When the equipment is installed deep in the switchgear, an extended rotating handle is required. At this point, the Push to trip button is located on the device body rather than the cabinet door. During testing, it is necessary to:

Place the device in position O and open the cabinet door.

Use specialized tools (open-end wrench or LV426937 operator) to rotate the extension shaft to position I.

Press the Push to trip button on the device.

Use a tool to turn the shaft counterclockwise back to the O position and close the cabinet door.

Locking and secure isolation

3.1 Direct handle padlock

Standard lock: Up to three padlocks (lock beam diameter 5-8mm) can only be used in the O (OFF) position.

Optional dual position locking: After modifying the handle, it can be locked in both I (ON) and O (OFF) positions. Attention: When locked in position I, the protection function is still effective; If an electrical failure occurs, the equipment will still trip, and the handle will display the Trip position after unlocking.

3.2 Door Interlocking (MCC Function)

The MCC adapter board with a direct handle can achieve interlocking between the cabinet door and the handle: when the handle is in the I (ON) position, the cabinet door cannot be opened to prevent electric opening. Only qualified personnel can temporarily disable this interlock, for example, to perform measurements in the closed state. To disable the operation, the handle needs to be modified. Please refer to the dedicated manual GHD16295AA for details.

3.3 Extend the door lock function of the handle

The extension handle comes standard with locking the door in the I (ON) position. It can also be temporarily disabled, but reference should be made to GHD16292AA (GV5) or GHD16320AA (GV6). Typical application scenario: When the handle of the circuit breaker in the incoming cabinet is in the ON position, the door is locked to ensure that other motor circuits are still live when the door is opened for maintenance, but the operator cannot touch the busbar.

3.4 Isolation Capability

The TeSys GV5/GV6 equipment complies with the isolation requirements of IEC/EN 60947-1 and 60947-2, and the isolation symbol is marked on the nameplate. Place the handle in O (OFF) and lock it to safely carry out downstream equipment maintenance work.

Detailed explanation of protection function

This series of trip units integrates multiple protections and can be set through panel dialing. The following table shows a list of key parameters:

Parameter function adjustment range default value SDTAM linkage

Ir overload protection setting current 0.4 × In~In 0.4 × In is

Class Tripping Level 5, 10, 20 10 No

Isd short delay protection setting multiple 5-13 × Ir 13 × Ir No

Tsd short delay fixed delay not adjustable (20ms hold+60ms maximum break) - No

Ii instantaneous protection multiple fixed at 15 × In - No

Lunbal phase loss/imbalance protection fixed at 30% - Yes

Tunbal Unbalanced Delay Start at 0.7s/Steady State 4s - No

4.1 Overload/Thermal Protection (ANSI 49)

Adopting I ² t inverse time characteristic and simulating motor thermal imaging (including iron loss and copper loss). The Ir setting value is set through multi gear dialing (e.g. 150A trip unit: Ir gear ranges from 70A to 150A). The maximum tripping time for Class corresponding to 7.2 × Ir is:

Class 5: 4-5 seconds

Class 10:8-10 seconds

Class 20:16-20 seconds

Thermal memory function: The release unit will remember the heat accumulation in the past 20 minutes. Even if there are multiple short-term overloads (a single one is not enough to trip), the accumulated heat will still cause the final trip, which more accurately reflects the temperature rise of the motor.

Self cooling motor: Thermal imaging calculation assumes that the motor is self ventilated (shaft end fan). If the motor is for forced ventilation, it is necessary to reduce the rated use or consult the manufacturer.

4.2 Short Delay Protection (ANSI 51)

Short delay protection is used to avoid motor starting current (usually 6-8 × Ir) and quickly cut off short circuits at the end of the feeder. Isd can be set to 5-13 × Ir (step size 1 × Ir). The fixed time delay is:

Holding time: 20ms (allowing starting current to pass)

Maximum breaking time: 60ms

This protection is combined with instantaneous protection to achieve selective coordination.

4.3 Instantaneous protection (ANSI 50)

The instantaneous protection is a fixed value of 15 × In (In is the maximum rated current of the trip unit). For example, the GV6 device with 320A has an instantaneous operating current of 4800A, an accuracy of ± 15%, and a maximum breaking time of 30ms. This value is much lower than the contact repulsion level, ensuring rapid breaking under extremely high short-circuit currents.

4.4 Phase Loss/Unbalance Protection (ANSI 46)

Unbalance calculation formula:

Iavg=I one+I two+I three three,unbalance ratio=max(∣Ik−Iavg∣Iavg)×one hundred%

I avg= threeI one+I two+I three

Imbalance rate=max（I avg∣I k−I avg∣)×100%

Fixed setting value of 30%. The delay is divided into two sections:

Start up phase: 0.7 seconds (greater risk of imbalance during motor start-up)

Steady state phase: 4 seconds

Phase loss (zero current in one phase) belongs to extreme imbalance and also triggers protection. This protection cannot be turned off and is always in effect.

Reflex Tripping

The unique reflective trip system of TeSys GV5/GV6 uses the pressure generated by short-circuit current to directly drive the piston to impact the trip mechanism, without the need for an electronic trip unit. This makes the breaking speed extremely fast (less than 10ms), especially suitable for situations with high expected short-circuit currents. The reflection trip curve is only related to the rated current of the equipment and does not depend on the setting.

Practical significance: In cascade protection, the reflection trip of upstream GV5/GV6 can limit the short-circuit current of downstream equipment, allowing the use of lower level switches with lower breaking capacity, thereby reducing costs.

Electrical auxiliary accessories and fault indication

6.1 Indicator contacts (OF, SD, SDE)

OF: Indicates the position of the main contact (ON/OFF)

SD: Indicates any cause of tripping (including manual push testing, undervoltage tripping, overload, short circuit, phase loss)

SDE: Only indicates electrical fault tripping (overload, short circuit, phase loss), excluding manual testing and voltage trip operation.

The logical states of these contacts are detailed in the table below (using NC/NO transformation):

Handle position OF (1 → 2) SD (1 → 2) SDE (1 → 2)

OFF Close Close Open

ON Open Close Close Close

Electrical fault tripping, closing, opening, closing

Voltage release/push in test trip closed open open

6.2 Voltage Release Device

MN/UVR undervoltage trip: trips when the voltage is below 0.35 × Ue; When the voltage is between 0.35-0.7Ue, it may trip; When it is higher than 0.7Ue, it will not trip. The restoration voltage needs to reach 0.85Ue before it can be closed again. Commonly used for safety emergency stop.

MX/SHT shunt trip: When the control voltage exceeds 0.7 × Ue, the trip can be triggered by pulse or continuous signal (≥ 20ms).

It is recommended to test the operational reliability of the voltage release every six months.

6.3 SDTAM Thermal Fault Module

This module communicates with the trip unit through an optical link and provides two static outputs:

Output 1 (SD2): Normally open contact, activated when overloaded or severely unbalanced, and remains in state until manually reset or delayed automatic reset.

Output 2 (SD4): A normally closed contact used to control the contactor coil. Open 400ms before tripping, so as to disconnect the contactor first and then release the circuit breaker. This can:

Reduce the stress borne by the motor

Avoid frequent breaking of high current by circuit breakers to extend their lifespan

When the fault is temporarily eliminated (such as when the startup time is too long due to voltage sag), it can be automatically restored without the need for manual resetting of the circuit breaker.

Reset method:

Manual: Set the SDTAM dial to the OFF position, power off and then power on again.

Automatic: Set the dial to the 1-15 minute range and reset automatically after a delay (matching the motor cooling time).

Attention should be paid when wiring: if the power consumption of the contactor coil exceeds 80mA, an intermediate relay must be isolated.

Environmental adaptability and derating

7.1 Temperature and altitude

Operating temperature: -25 ° C to+70 ° C (-35 ° C to -25 ° C can be adjusted but long-term operation is not guaranteed)

Storage temperature: -50 ° C to+85 ° C

Altitude reduction:

Below 2000m: rated voltage 690V, current not reduced

3000m: maximum voltage 690V, current 0.98 × In

4000m: maximum voltage 635V, current 0.96 × In

5000m: maximum voltage 560V, current 0.94 × In

7.2 Vibration and EMC

The equipment has passed the vibration test certified by DNV-GL classification society: amplitude ± 1mm at 2-13.2Hz, acceleration 0.7g at 13.2-100Hz. The electromagnetic compatibility complies with Appendix F and J of IEC/EN 60947-2, and can resist operating overvoltage, lightning, walkie talkie radiation, and electrostatic discharge, avoiding accidental tripping.

Troubleshooting and maintenance recommendations

8.1 Common Problems and Countermeasures

Possible causes and steps for handling the phenomenon

The handle is on Trip, unable to reset downstream short circuit or overload. Check the insulation resistance, motor winding, and cable. Reset after repair

Equipment trips without reason, no SDE signal voltage release misoperation or push in test to check if the control voltage is stable, and if MN/UVR is below 0.7Ue

If the green READY LED does not flash and the load current is below 30A (LED does not work) or if the trip unit is faulty and the load is greater than 30A and the LED is off, the trip unit needs to be replaced

Red ALARM LED always on thermal imaging>95% Ir. Check if the motor has been overloaded for a long time or if there is poor ventilation

Unbalance protection frequently operates, three-phase current deviation>30%. Check for contactor contact fusion welding, power phase loss, and local short circuit in motor winding

8.2 Maintain operational safety

Before conducting any internal inspection, the handle must be placed in O and locked, and a voltage tester must be used to confirm that there is no voltage at the upper and lower ports.

After a short circuit trip, the main contact should be checked for burn damage and the mechanism should be checked for jamming. If necessary, conduct a verification of the breaking ability.

Regularly (annually) use Push to Trip to test the protection function; For the SDTAM module, it should be tested whether its output operates 400ms before overload.