Siemens Loher – The Leading Expert for Explosion-Proof Motors

Both motor series – Siemens Loher CHEMSTAR and Siemens Loher VARIO – set standards in drive technology in the chemical and petrochemical industries as well as oil and gas sector. This is because they comply with all of the industries´requirements and reflect the many years of experience that Loher has been engaged in this sector. The decades of experience that Loher has in the development, design, engineering and production of explosion-proof motors guarantees an optimum of operational safety, availability and adaptation to the particular application conditions.

Not only are they extremely rugged and reliable, but they can also be supplied in all of the applicable types of protection Ex n, Ex e, Ex d, Ex p. And for exceptional requirements, they are also available in double protection types, gas/dust or Ex e and Ex d. All of this is supplemented by additional features that protect the motors against aggressive atmospheres – such as a chemical-proof paint finish and galvanized fan cowls. They also have a wide range of permissible operating temperatures, which makes them ideal for applications in deserts and polar regions. The motors are also available with degrees of protection up to IP68 and naturally have sector-specific certificates such as ATEX, NEPSI (China), CCOE (India) and Rostekhnadzor (Russia).

The economic and ecological drive solution

Loher CHEMSTAR and Loher VARIO motors are the economic and ecological drive solution for applications in the chemical and petrochemical industries as well as in the oil and gas sectors. These motors are used in all of the associated production areas – from upstream through midstream to downstream. They form a complete, seamless portfolio of explosion-proof three-phase motors from 0.12 kW up into the Megawatt range. The spectrum of Loher CHEMSTAR motors ranges from 0.12 up to 315 kW; the VARIO series continues the range in the low and high-voltage ranges all the way up to 2,800 kW. Both of these series guarantee users high benefits:

Low “Cost of Ownership” as well as high quality result in maximum cost-effectiveness.

When developing the Siemens Loher CHEMSTAR and Siemens Loher VARIO series of motors, we took into account all of the sector-specific requirements, especially regarding the following:

•• Explosion protection

•• Degree of protection

•• Corrosion protection

•• Noise level

•• Service life

•• Maintenance

•• Repair

•• Replaceability

•• Availability

•• Cost-effectiveness

•• Environmental-friendliness

Explosion-proof motors also in high efficiency design

The new international efficiency standard IEC 60034- 30 now also includes explosion-proof motors – clearly reflecting the ever increasing significance of energy efficiency. Specifically for this reason, Loher has also developed a new series of flameproof motors (class of protection Ex d) in the high efficiency classification IE2. These high efficiency Ex d motors in IE2 cover a power range from 0.75 kW to 375 kW. They are available as 2, 4 and 6-pole motors for operation both at 50 and 60 Hz.

Maximum safety – quality motors that withstand any pressure

Double protection for exceptional requirements

The Siemens Loher CHEMSTAR and Siemens Loher VARIO motor series are also available with double protection to address exceptional requirements: This is a combination of gas and dust explosion protection for locations where both fine dust and explosive gases can occur simultaneously (no hybrid certification). The other option is double protection in Ex d and Ex e. Such a type of double protection is, for instance, practical for cargo pumps installed on liquid gas tankers. In this case, it must be absolutely ruled-out that the electrical equipment is a potential source of ignition due to the dangerous freight that is being transported.

In this case, Loher mechanically designs the explosion- proof motors with type of protection “flameproof encapsulation” – and at the same time, ensures that the temperatures of the active parts and components correspond to type of protection “increased safety”.

In addition to the application-specific advantages – such as reliability, operational safety, efficiency and explosion-protection – we also offer the two Siemens Loher CHEMSTAR and Siemens Loher VARIO series of motors as total package to optimize the complete supply chain:

In this case, users profit from the low lifecycle costs as a result of the high quality, cost-effective operation, simple service and maintenance and long service life.

In the planning phase, the focus is on the technical specifications and the simplified documentation. A complete package of documentation is available for planning purposes. The optimized ordering process to minimum purchasingcosts is yet another advantage. This is complemented by shorter procurement times as a result short, flexible production times.

For low and medium power ratings, it is especially the Siemens Loher CHEMSTAR motor series that ensures a maximum degree of safety and reliability, highest availability and low operating costs. With a power range from 0.12 to 315 kW, Loher CHEMSTAR motors cover all conceivable types of protection. A sector-specific design takes into account the application and installation location. For instance, a highquality paint finish that is especially resistant to chemicals and the galvanized fan cowl protect against aggressive atmospheres. Even when there is a high degree of humidity, anticondensation heating is frequently not required. Loher CHEMSTAR motors operate perfectly from -55°C (-67°F) to +70°C (158°F) – also in zones with dust and gas. These motors are even optimally equipped to cope with desert and polar climates.

When specified, the motors can be equipped with corrosion-resistant stainless steel screws and bolts and many other design features. Shaft seals with an IP66 degree of protection against water and dust are available. Although the standard degree of protection is IP55; degrees of protection are available up to IP67. The motor frame is manufactured out of rugged gray cast iron. This makes it extremely resistant to corrosion, it dampens vibration and has a high mechanical strength. Reinforced bearings and integrated PTC thermistor are some of the options that can be ordered. The motor versions that can be adapted comply with almost all user requirements and specifications. CHEMSTAR motors are supplied with sector-specific documentation including ATEX certificates for the chemical and petrochemical industries.

Siemens Loher VARIO motors – maximum safety in the oil and gas sector

Loher VARIO motors are available in all of the usual voltages and frequencies up to 11 kV. They distinguish themselves as a result of the extremely rugged design. Torsionally stiff steel frames – that at higher power ratings offer increased stiffness and lower vibration – ribbed bearing endshields in gray cast iron or steel with a high mechanical strength. Vertical motors can also be equipped with thrust bearings for high axial and radial loads. The high efficiency is obtained by using magnetic slot wedges – resulting in significantly lower power costs. The terminal box can either be mounted on the side or at the top – other modifications are available on request. All of the terminal boxes can be rotated through 90°. In a welded steel design from shaft height 355 and above, the Siemens Loher series of VARIO motors is either available as low-voltage or high-voltage motor depending on the particular application. Siemens Loher VARIO low-voltage and high-voltage motors are equipped as standard with the features that are required for applications in the oil and gas sector as well as the petrochemical and the chemical industries.

This series of motors fulfills the standards of the various operating companies to a high degree. With power ratings up to 2,800 kW, their main applications are in the oil and gas sector where high-rating pumps and compressors are required for pumping and transporting oil and gas. They can be used in any hazardous zone – up to gas group II C in compliance with Class II 2 G Ex de II C T4. Equipped with roller bearings, VARIO motors are predestined for applications in hazardous Zone I and in highly explosive environments containing hydrogen. The complete range is certified according to ATEX, NEPSI, CCOE and Rostekhnadzor – also for extremely low temperatures. All of these features make these motors admirably suited for  applications in oil and gas fields in cold regions such as Canada, Alaska and Siberia.

•• 280 kW to 2,800 kW

•• Voltages from 380 V to 11,000 V

•• Shaft heights from 355 to 630

••Welded steel stator housing

•• All types of explosion protection – including double protection

•• Degrees of protection IP56, IP67, IP68

•• Special paint finishes in all of the usual colors (RAL or Munsel)

•• Suitable for the most extreme ambient conditions, e.g. offshore platforms

•• Can be connected either directly to the line supply or drive converters

••Mounting arrangements IMB3, IMB35, IMV1

•• Totally enclosed fan cooled (TEFC), cooling type IC411 or IC416 with forced ventilation

•• In compliance with DIN ISO, EN and IEC

•• Ex e high-voltage terminal boxes with new safety system

•• Certified according to international regulations

For high power ratings, additional motor series and cooling types round-off the portfolio for oil and gas sector and the petrochemical and chemical industries: Pipe-cooled motors, open-circuit ventilated motors, motors with mounted air-to-air or air-to-water heat exchangers. Whether as explosion-proof motor or motor for safe environments – in shaft heights from 355 to 800, the range of applications that can be addressed up to 10,000 kW has almost no limits.

For more info please contact: Christian Bohnert

Siemens AG
Industry Sector
Drive Technologies Division
Large Drives
I DT LD AP OGP VMM BD
Gugelstr. 65
90459 Nürnberg, Deutschland

Tel: +49 911 433-2310
Fax: +49  911  433-9752
mailto:christian.bohnert@siemens.com