Three Phase Advanced SCR Power Regulator

1. Ordering Information



2. Ordering Example

MW30E-250-P--- MW30E series, 250 amps, with profibus DP communication

3. Detailed Information we need so that we can choose correct SCR for your application

--Please identify your load type, is it a resistive load like heaters, IR lamps , or inductive load like transformer ?
--What is the total power of your load,  in this artical, we are going to use a practical example, say we have a heater system at 36KW, 400V source
--What is your electrical circuit ?  it would be Delta, Star(Wye), or Star with neutral wire
--For a typical heater with 36KW, 400V source at Star configuration, the phase current will be 52.17 amps
--For MW30E series SCR,  the correct model would be MW30E-075,  75 amps SCR will do the job,  we have 50 amps version, but 52.17 already exceed the rating, so the better choice would be 75 amps
--One of unique feature of our MW30E is that the SCR can be use up to 100% it's rating , the 50%, 40% derating policy is not necessary for our MW30E SCR
--Please download PDF file as below to have a better understanding on the relation between phase voltage, phase current and line voltage, line current in different electrical circuit.

[PDF] How to calculate your phase current to select correct SCR

Documents and Dowloads

[PDF] MW30E Catalog and user manual

Q: What types of loads is the MW30E suitable for?
A: The MW30E is a highly versatile power regulator suitable for resistive, inductive, and capacitive loads, depending on the selected control mode. It is ideal for industrial heating elements, transformers (primary/secondary side control), and induction melting applications.

Q: Does the MW30E support constant current or constant voltage control?
A: Yes, the MW30E features advanced closed-loop PID adjustment that allows it to maintain either a constant output voltage, constant output current, or constant output power, automatically compensating for grid voltage fluctuations or changes in load impedance.

 Q: Can I connect the MW30E to my existing PLC or SCADA system?
A: Absolutely. The MW30E comes standard with an RS-485 communication interface supporting the Modbus-RTU protocol. Optional expansion modules are also available for Ethernet and Profibus DP communication.

 Q: How does the zero-crossing control mode benefit my application?
A: Zero-crossing control switches the power on and off precisely when the AC voltage crosses zero. This significantly reduces harmonic distortion and electromagnetic interference (EMI), while maintaining a power factor close to 1, making it an excellent choice for purely resistive loads.

Q: What happens if the regulator overheats or experiences an overcurrent?
A: The MW30E is equipped with comprehensive protection systems. If the current exceeds 125% of the rated value, it will trigger an overcurrent alarm and take protective action. Similarly, if the thyristor temperature exceeds 85°C, the unit will issue an alarm and halt output to prevent thermal damage.

Q: Can the display panel be mounted externally on a cabinet door?
A: Yes, an optional external display and operation panel (module code ED) is available. It can be connected via a standard network cable (up to 4 meters) and mounted on the cabinet door for convenient real-time data observation and parameter setting without opening the enclosure.

Q: What is the "Online Power Allocation" function mentioned in the catalog?
A: Online power allocation is an optional advanced feature designed for systems with multiple power regulators. It synchronizes the power distribution among connected devices to prevent simultaneous peak power draws, thereby improving bus current continuity and reducing the overall load on your electrical infrastructure.

Q: What are the methods of firing SCRs ?
A: There are two methods for firing SCR power controllers: Zero cross and phase angle. Not all SCRs can be fired by both methods, and some situations dictate the method required. Typical, traditional heaters are made with Nichrome wire, which supports both zero-cross and phase-angle firing. This gives you flexibility when selecting an SCR for your system.
Please download a word file from below for detailed explanation on the firing modes of a SCR, the pros and cons for different firing modes

[WORD]What are the methods of firing SCRs ?