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Contactors and Motor Starters
Electronic soft starters
Electronic soft starters
The MCI soft starter range are designed for soft starting and stopping of 3 phase a.c. motors,starting of 3 phase compressors (MCI C) and starting small commercial refrigeration units & heat pump...
Approvals & certificates (1)
What is special about the MCI Compressor Starter? Can I use a “normal” MCI soft starter to soft start a compressor?
Answer: Yes, a normal MCI can be used to control (soft start) a compressor. The difference is that the MCI Compressor soft starter is pre-set from factory to ensure fast and reliable start of three phase compressors.
Can the MCI soft starter be used as a switch or do I need also to install a contactor?
Answer: The MCI can be used as a switch, therefore it is not necessary to use an additional contactor. The type of equipment that can be used for operational switching is specified in EN 60364-5. Included here are: contactors and semiconductor devices. It is also specified that not all conductors have to be connected. The conclusion is that a two-phase disconnection by semiconductors is sufficient to meet the requirements in relevant standards for operation of motor loads. Therefore there is no difference between a contactor breaking all three phases mechanically and a semiconductor motor controller like the MCI.
Why does the MCI soft starter only control 2 of the 3 phases?
Answer: From a technical point of view, it is not necessary to control all three phases except for bigger motors where a high starting torque is important. The un-controlled phase will “follow” the other two phases and the starting current will be reduced in all three phases. The un-controlled phase current will always be approx. 15% higher than the controlled phases.
What is a “thyristor” and what does “LTE” mean?
Answer: "thyristor is a semiconductor. In each of the controlled phases a thyristor pair is used. In a CI-tronic™ component the semiconductor is used as the mains switch with or without a ramp up/down function. Sometimes the semiconductor or thyristor is referred to as a power chip. LTE means low thermal expansion. When a semiconductor is switched, its temperature will change rapidly. It is therefore vital that the materials used in its construction have similar coefficients of expansion to avoid mechanical stresses that could be detrimental to the semiconductor."
Why do the MCI 15 and MCI 25 not feature integrated by-pass of semiconductors?
Answer: "An automatic by-pass function would require integration of mechanical relays. This would restrict the MCI application and limit the number of starts per hour. Instead the semiconductor design allows that the conductors stay in circuit also when the motor is running with nominal speed. Furthermore the heat sink design ensures that the MCI can withstand maximum load even at an ambient temperature of 40¢ªC. The maximum load is expressed in the rating index according to EN 60947-4-2: Example with MCI 25: AC-53a: 25A: 8-3:100-3000 AC-53a is the load category for asynchronous motors. 25A is the max. permissible load for the MCI 25. 8-3 means that the start profile can be 8 * 25A = 200 A for 3 seconds. A 100% load factor or 3000 operations per hour is accepted."
What does “automatic detection of missing phases” mean?
Answer: "The MCI can detect if a motor phase (load) or supplying phase is missing. In such situations the two LEDs will flash and the MCI will not activate. It will only detect the phase failure in stand-by mode. The MCI should always be connected to a three-phase motor in order to be operated. "
Where can I find approvals and certificates for Danfoss products? E.g. do you have a PED certificate for KP7W?
Answer: You can find product approvals and certificates for all our products on our internet website. Follow this link to search for documents either by product or by authority: http://www.danfoss.com/BusinessAreas/IndustrialAutomation/Documentation/Approvals+and+Certificates.htm
Do Danfoss products comply with RoHS directive (Restriction of Hazardous Substances)?
Answer: Yes, all declarations of conformity, including RoHS and WEEE, can be found in our internet product catalogue. Look up the product of your interest and find the relevant document either under the Literature link or the Approvals & Certificates link.
Do you have a soft motor starter for 100 HP?
Answer: MCI 50-3 I-O, the biggest soft starter in our CI-tronic™ range, is for a max. motor power of 40 HP if bypassed during steady state. For even higher rating, we recommend the Danfoss MCD soft starters from the VLT® Drives range.
I'm looking for a Danfoss code number and I have not found it in any catalogues?
Answer: Som code numbers are not available for all markets, or it may have been replaced by another number. To resolve the issue, please contact your nearest Danfoss office: http://www.danfoss.com/Contact/Worldwide/
Could I send you a Danfoss part for repair?
Answer: Danfoss does not have repair departments locally. For warranty or complaints issues, please contact your nearest Danfoss sales office and they will tell you how we handle these issues in your area.
Can you deliver your products worldwide?
Answer: Yes, we have own distribution centres across the world, working together with more than 100 distributors and agents. You can see your nearest distributor or Danfoss office here: http://www.danfoss.com/Contact/Sales_and_Services/
Do you have a complete catalogue showing all your products?
Answer: Our internet product catalogue is the most extensive information source: http://www.danfoss.com/Products/Categories/ Besides these products, Danfoss also produces customer-specific products and solutions that are not visible in the catalogue. Please contact your nearest Danfoss office to discuss your needs and how we can meet them.
Can you deliver products exclusively made for us?
Answer: Yes, we have the possibility to develop products that are unique for one customer subject to individual agreements. The products may differ in appearance, technical features or packaging. Please contact us to discuss your requirements.
Which distribution channels does Danfoss use?
Answer: Danfoss makes use of different channels, including distributors, to suit the markets' needs. An increasing number of our customers use our web ordering and EDI e-commerce solutions.
Can I review your stock online?
Answer: Yes. By using Danfoss web-ordering, you can check product availability. Please contact Danfoss to get access to web-ordering.
Where can I find technical drawings of Danfoss products?
Answer: Dimension and function drawings of our products are often part of the products'' technical leaflets. In our internet product catalogue (http://www.danfoss.com/Products/Categories/), find the product of your interest, then follow the Literature link to see available items.
I have mounted a Softstarter MCI C on my air compressor - why doesn't it work?
Answer: For your compressor, you should use a standard MCI softstarter where you can adjust the start parameters. The MCI C compressor soft starters are specifically designed for soft starting of 3-phase compressors and have default settings.
How do I select the correct soft starter?
Answer: First you have to keep in mind that a soft starter reduces the starting current. You must select a softstarter which supplies adequate current to ensure smooth operation of the motor or application. Please consider the number of starts per hour and the ambient temperature and also the necessary monitoring and control functions.
Where do I direct commercial or technical questions?
Answer: Danfoss worldwide sales and services is available here: http://www.danfoss.com/Contact/Sales_and_Services/ Your nearest Danfoss office will be able to answer your question, or have it directed to the appropriate expert.
Do you have local stock?
Answer: This depends on the country and product concerned. Our logistics are set up to achieve competitive and reliable delivery performance for our customers.
Where can we find your data sheets?
Answer: All relevant literature, including technical brochures, are available on our Web site: http://www.danfoss.com/BusinessAreas/IndustrialAutomation/Documentation/Industrial+Automation+Literature.htm
Do you have local websites in my language?
Answer: Yes, please see http://www.danfoss.com/ and then use the "Local sites" option in the top righthand corner.
Is it possible to place orders online?
Answer: Yes, you can place orders and access order information online. Please contact Danfoss to get access to web-ordering. You can see the benefits of Danfoss web-ordering at http://www.danfoss.com/Products/ebusiness/
Does Danfoss operate globally?
Answer: Yes. More than 100 Danfoss sales companies and more than 100 agents are spread across the world, making Danfoss nearby, always.
Is Danfoss a German company?
Answer: No, it is a globally acting group with headquarters in Denmark.
Do soft starters have any internal protection?
Answer: No, they do not have any protection. You need to use a circuit breaker before the soft starter, or use fuse and contactor with thermal relay, which ensures protection againts overloads and short-circuit.
What is maximum overload current of soft starters?
Answer: Maximum overload current for soft starters is 6xIn or 8xIn (where In is nominal current). For more details (duty ratio, number of cycles/hour, time between each start operation) please refer to overload current profile in our technical brochure.
I have a 21 kW motor application with star-delta starter, how can I change to softstarter in the cheapest way?
Answer: We recommend the MCI 40 with inside-delta connection.
What is trip class?
Answer: Trip class is the expression used in connection with the designation and current settings of overload relays and soft starters. The most popular are 10A and 10 trip classes. They are suitable for light/standard duty applications. Trip class corresponding to minimum overload current withstand time. For example: Class 10A = overload ratio 8 (8 times nominal current) for 1.6 seconds; Class 10 = overload ratio 8 for 3 seconds.
What is the maximum starts and stops of my TCI softstarter?
Answer: The TCI softstarter range has unlimited start/stop operations per hour.
Where can I find some technical information about your products?
Answer: Please see our online product catalogue: http://www.danfoss.com/BusinessAreas/IndustrialAutomation/Product+catalogue/IA+product+catalogue.htm
What is the difference between MCI xx and MCI xx C families?
Answer: There is almost no hardware difference between the MCI xx and MCI xx C families, but the MCI xx C series has factory-fixed settings for compressor applications.
Why do we bypass the soft starter in steady state?
Answer: Bypass is important when the soft starter is working in temperature above 40 °C – in this case you don't have to reduce load or duty cycle when the soft starter is bypassed in steady state. Moreover bypass eliminates the electromagnetic disturbances EMC during the full voltage operation.
Does the MCI-CH have some protection against phase change?
Answer: No, MCI-CH has no phase change detection implemented.
What is the difference between the AC-3 and AC-4 categories?
Answer: The AC-3 category is dedicated to squirrel-cage motors; starting, disconnecting while running, whereas AC-4 is dedicated for control of squirrel motors, starting, plugging, inching. When we perform laboratory tests AC-3 means that make current is 6 x In (nominal current), brake current is 1 x In. AC-4: make current 6 x In, brake current 6 x In.
How should I interpret MCI rating index AC-53b?
Answer: AC-53b:6-6:30 means: Motor controller rating with bypass contactor; overload capability 6-6 - 6x nominal current for 6sec; 30 means time in seconds between each start operation.
How should I interpret MCI rating index AC-53a?
Answer: AC-53a:6-5:100-480 means: Motor controller rating without bypass contactor; overload capability 6-5 - 6x nominal current for 5sec; duty ratio in % - 100%= continuous operation; 480 means number of cycles per hour.
What does AC-53a and AC-53b stands for and what is a difference?
Answer: There are two basic utilization categories for AC semiconductor motor controllers (MCI xx): AC-53a and AC -53b. AC-53a describes operational capabilities of controlling squirrel cage motors by semiconductor controller (MCI) AC -53b describes operational capabilities of controlling squirrel cage motors by semiconductor controller (MCI) bypassed during running. Note: The means of bypassing controller may be integral with the starter or installed separately
Can you send me literature, brochures or catalogues on your products?
Answer: We appreciate your interest and will happily send you an overview of our offering in print. Please contact your local Danfoss office or e-mail us on firstname.lastname@example.org, describing your interest and application.
I placed an order through e-commerce. Could you please check the delivery dates and inform me the earliest possible delivery?
Answer: Delivery dates are supplied in the e-commerce system and based on Danfoss standards. If the confirmed delivery date is not acceptable, please contact Danfoss through e-mail or telephone.