Siemens Low Voltage Switchgear: Complete Guide for Plant Engineers

The low voltage switchgear range offered by Siemens includes equipment for power distribution, circuit protection, motor control, and electrical instrumentation. These include 3VA MCCBs ranging from 16A to 1600A, 5SL/5SP/5SY MCBs, 3RT contactors, SIRIUS 3RW soft starters, and SENTRON 7KM power meters. The proper selection of suitable combinations for an industrial plant in Vadodara or any other part of Gujarat would depend on various factors such as load current, fault level, and motors’ rating.

What Is Siemens Low Voltage Switchgear?

The low voltage switchgear is employed to operate, protect and distribute electrical energy in systems that run at low voltage.

A typical electrical installation at an industrial facility will not comprise a single component; an electrical installation will usually consist of an incomer breaker, a distributor breaker, motor control devices, contactors, overload/motor protection, metering and bus bar system.

Siemens manufactures all the aforementioned products. Therefore, the product range is suitable for installations where it is necessary to coordinate the electrical energy distribution and control system rather than separate components.

For example, a factory distribution system will have a Siemens 3VA MCCB on a feeder, a Siemens MCB on a smaller outgoing and 3RT contactors to switch motors.

Siemens Low Voltage Switchgear Product Range

Transpower Technologies supplies a comprehensive Siemens low voltage switchgear portfolio for industrial applications. The range can broadly be divided into power distribution, control, motor protection and monitoring.

These specifications reflect Transpower’s documented Siemens LV portfolio. Product selection should always be confirmed against the current manufacturer’s technical documentation and the actual application.

Siemens 3VA MCCB for Industrial Power Distribution

A Moulded Case Circuit Breaker (MCCB) is generally utilized when there is a requirement of higher capacity in the current compared to MCB usage.

The Siemens 3VA MCCBs that Transpower has include current ratings between 16A to 1600A. This offers the plant engineers a wide range of options for feeder and distribution applications.

An MCCB that will be right cannot solely be decided based on the current of the connected load alone. The prospective short-circuit current, cable capacity, and method of installation should also be considered.

These calculations should have been done before the breaker rating is finalized.

Siemens MCBs for Smaller Circuits

MCBs are usually used for lower currents in final circuits and distribution circuits.

The Transpower Siemens range includes 5SL, 5SP, 5SY and QC series MCBs, where the listed QC range covers 2A to 125A.

MCB selection is not limited to amperage considerations. The engineer needs to look into the load served, size of the conductors, fault current levels, and tripping characteristics desired.

For instance, MCBs installed in control circuits need to be chosen based on the operating characteristics of that circuit as opposed to choosing an MCB rated for a circuit next door.

The task is simple: the protective equipment needs to trip a fault before the cable or served equipment experiences damage.

Siemens 3RT Contactors for Motor Control

Contactors are an important component of industrial motor control panels.

There are Siemens 3RT contactors available in Transpower’s catalog, ranging from 9A to 1200A. These contactors are used for switching motor loads and other electrical loads in industrial control systems.

It is important that the contactor be suitable for the application because its selection depends on motor duty cycle, current, voltage, switching frequency, and control voltage.

The motor starter can incorporate the contactor along with motor protection. The particular configuration will depend on motor type and starting method.

In more automated applications, contactors can be used together with PLC control systems, VFDs or soft starters.

Siemens SIRIUS 3RW Soft Starters

Large motors generate considerable starting currents when directly connected to the mains.

The use of a soft starter assists in controlling the acceleration of a motor during the start-up phase and minimizes the stresses caused by direct starting.

Transpower’s Siemens range of equipment features the SIRIUS 3RW series of soft starters from 7.5kW up to 710kW.

Such products could be used for applications like pumps, fans, compressors, and conveyors that need controlled motor starting.

It should be noted, however, that a soft starter might not always be the correct choice for all kinds of motors. There are cases when the process calls for speed control rather than starting/stopping control.

How to Select Siemens Low Voltage Switchgear for a Factory?

The first step is to understand the electrical system rather than starting with a product number.

Calculate the Connected Load

Prepare a proper load schedule covering motors, heaters, lighting, HVAC, process equipment and other electrical loads.

Motor starting conditions should also be considered where applicable.

Check the Fault Level

Short-circuit current is one of the most important parameters when selecting protective equipment.

The selected protective device must have suitable interrupting capability for the installation’s prospective fault current.

Select the Correct Current Rating

The breaker rating must coordinate with the actual load and conductor capacity.

Oversizing a protective device simply to avoid nuisance tripping can create a protection problem if the cable is not adequately protected.

Plan Protection Coordination

Upstream and downstream devices should be considered together.

Proper coordination can help ensure that a fault on one feeder does not unnecessarily shut down an entire production section.

Consider Future Expansion

Industrial plants rarely remain electrically static.

If a production line is expected to expand, the distribution system should be reviewed for future capacity rather than being designed only around the present connected load.

Siemens Switchgear for Chemical and Pharmaceutical Plants

Electrical requirements for chemical and pharmaceutical industries are very stringent.

In Gujarat, industrial estates such as Makarpura GIDC, Vadodara, and other industrial estates feature factories that need reliable electrical supply for manufacturing.

Switchgear selection depends on factors like environment, cabinet location, loads, and maintenance needs.

In case of hazardous locations, the electrical installation will depend on factors such as hazardous area classification and requirement of certified equipment. It is not safe to assume that all low-voltage switchgears will be suitable for any hazardous location.

Here is where application-oriented selection becomes useful. Proper selection of breakers and control components depends on application.

Why Buy Siemens Switchgear Through an Experienced Industrial Supplier?

Product availability forms just one element of switchgear procurement.

The plant engineering staff and the procurement staff also require accurate product identification, guidance on applications and prompt delivery of the same.

Transpower Technologies Pvt. Ltd., located at 346 GIDC, Makarpura, Vadodara, has been in industrial supplying business for over 70 years and has over 8,000 customers and over 10,000 SKU in their product lines. They supply Siemens LV switchgear along with motors, FRP products, gearboxes, and electric drives.

Such a wide range of products may come handy in the event of procurement of a project involving both electrical and electro-mechanical equipment from one source rather than procuring them separately.

For Siemens products, visit Transpower’s Siemens Switchgear products.

Conclusion

Siemens low voltage switchgear meets the important electrical requirements in an industrial setup, starting with 3VA MCCB and MCB up to 3RT contactors, 3RW soft starters, and SENTRON 7KM meters. The proper choice is determined by engineering considerations as against selecting a product based on its similar current rating.

Transpower Technologies, an industrial electrical supplier based in Makarpura GIDC, Vadodara, Gujarat, offers Siemens switchgear supply services in Vadodara, with more than 70 years of experience in the industry.

Check the Fault Level

Short-circuit current is one of the most important parameters when selecting protective equipment.

The selected protective device must have suitable interrupting capability for the installation’s prospective fault current.