MVX Soft Starter

Proud to announce the release of the world's smallest (and safest) MV soft starter - the MVX!

The Smallest Soft Starter in the World

MVX Soft Starter Drive

The MVX soft starter is the smallest medium voltage soft-starter in its class, with a smaller panel footprint than any other MV soft starter in the market today. Space is a big advantage in lowering your switchroom costs and provides more flexibility where space is needed like marine applications.

  • Current range: Up to 800A
  • Motor connection: Inline
  • Rated voltage class: Up to 15kV
  • Mains frequency: 45Hz to 66Hz

The safest soft starter in the world!

MVX - The Safest Soft Starter Drive

To ensure your staff and plant are safe from arc fault, the MVX is the only choice. The MVX meets or exceeds all the relevant IEC standards for internal arc fault resistance. The MVX L-series panels can even withstand an arc event in one compartment without affecting neighbouring compartments.

Easier to service

MVX - Service

We have eliminated complex disassembly to replace or service a part. The MVX starter with L-series panels are designed with easy rack-in, rack-out operation. Components can be inspected through viewing windows and are easily accessible via hinged doors or removable panels, while still keeping unauthorised people out.

More flexibility

Don't feel constrained in the choice of apparatus in your switchgear, MVX panels are compatible with all of the major apparatus suppliers.

The benefit of experience

At every stage of the process, we will work with you to create the ideal MVX solution to meet the needs of your application and budget.

The MVX soft starter is available in a range of configurations up to rated voltage class 15kVA and 800A. There is a full service capability to design and manufacture your entire Motor Control Centre.

MVX Specification


Mains Voltage

12 kV Phase-phase

Rated Frequency

50 Hz or 60 Hz

Rated Power Frequency Withstand Voltage (Ud)

42 kV

Rated Lightning Impulse Withstand Voltage (Up)

75 kV

Rated short-time withstand current (asymmetrical RMS peak) (Ik)

31.5 kA for 4 seconds

Form Designation

Bypassed semiconductor motor starter form 1

Control Inputs

Start (Terminals C23, C24)

24 VDC, 8 mA approx

Stop (Terminals C31, C32)

24 VDC, 8 mA approx

Reset (Terminals C41, C42)

24 VDC, 8 mA approx

Input A (Terminals C53, C54)

24 VDC, 8 mA approx

Input B (Terminals C63, C64)

24 VDC, 8 mA approx

Motor Thermistor (Terminals B4, B5)

Trip point > 2.8 kOhm

Control Outputs

Relay Outputs

10 A @ 250 VAC resistive
6 A @ 250 VAC AC15 p.f. 0.3
10 A @ 30 VDC resistive

Main Contactor (Terminals 13, 14)

Normally Open

Bypass Contactor (Terminals 23, 24)

Normally Open

Run Output/ PFC (Terminals 33, 34)

Normally Open

Output Relay A (Terminals 43, 44)

Normally Open

Output Relay B (Terminals 51, 52, 54)


Output Relay C (Terminals 61, 62, 64)


Analog Output (Terminals B10, B11)

0-20 mA or 4-20 mA


Equipment Class (EMC)

Class A

Internal Arc Classification (IAC)

AFLR to maximum of 31.5 kA for 1 second

Degree of Protection

Phase Cassette
IP54/ NEMA 12

Operating Environment

IEC60721-3-3: IE34: Climatic 3K4
-5 °C to 40 °C, with derating to 55 °C
Relative Humidity
5% to 95%

Storage Environment

IEC60721-3-1: IE12
- 5 °C to + 45 °C
Relative Humidity
5% to 95%
Pollution Degree
Pollution Degree 2
IEC 60068-2-6 Fc

Standards Approvals


EMC requirements


EMC EU Directive

MVX Protection Codes

Code Protection description MVX Protection (built-in)
48 Maximum start time Excess start time
66 Too many starts Restart delay and dynamic thermal model
37 Undercurrent
51L Load Increase (alarm) High current frequency output
51R Overcurrent - jam Excess start time, electronic shearpin
50 Overcurrent - short Shorted SCR, electronic shearpin
49/51 Thermal overload Thermal overload - dynamic model
46 Current imbalance Current imbalance
Positive/negative phase sequence Phase sequence
27 Undervoltage Undervoltage
59 Overvoltage Overvoltage
47 Phase loss Phase loss
47 Phase sequence Phase sequence
50G Ground fault Ground fault
3 Communications failure Communications failure
3 Internal failure Internal failure
86/97 Ext. fault 1/code - 1 Auxiliary trip A
Ext. fault 1/code - 2 Auxiliary trip B
38 Motor overtemperature Thermistor protection*
49 Stator winding overtemperature Thermistor protection*
32 Under power Power Loss

* RTD Relay is an optional extra.

MVX Documentation