Pressure Monitoring & Control Introduction Literature FAQ Photos Pressure Monitoring & Control Question: What is the neutral band (or neutral zone)?    Answer: The neutral band is common to a special series of RT switches, which have two set points, a high point and a lower point. The range in between these two switching points is called the neutral band. For instance, you may wish to have both a high pressure alarm as well as a low pressure alarm on a pressure vessel, in which case the ideal switch would be a type with a neutral band. Question: In my application there are pulsations. Which pressure switch should I choose?    Answer: When there are pulsations we recommend to use our diaphragm versions together with a damping coil, which is available as an accessory. Question: Is it possible to use Danfoss pressure switches when the medium is sea water?    Answer: Yes, but we recommend using only our diaphragm versions: KPS 43-45-47, CAS 143-145-147, MBC 5000/5100 with diaphragm type of sensor. Question: What is the maximum/minimum pressure/temperature at which Danfoss switches can be set?    Answer: Danfoss manufactures various pressure switches which can have a setting range of anywhere between -1 to 400 bar and temperature switches from -60 to +300°C. However, each switch will have its own regulation range as detailed within the product catalogue pages. It is always good practice to avoid choosing a product which will be switching near to the limits of its range. Question: What is the DIN numbering of terminals?    Answer: Terminal numbers are always ODD for inputs & EVEN for outputs, which explains why the changeover switch in almost all pressure & temperature switches has numbers 1, 2 & 4. The live feed goes in at 1. It comes out at 2 when the pressure or temperature is low (so take this to your pump or heater as a live feed) out of 4 when the temperature or pressure is high. (You can take terminal 4 to a ''satisfied'' tell-tale lamp or to an unloading valve or cooling fan, if you wish). Question: What is differential?    Answer: The differential is the difference between a switch cutting in and cutting out – it is like on a kettle after it has boiled and switched off, you can not switch it on again until the kettle has cooled down a little. Too small a differential will give rise to short running periods with a risk of hunting. Too high a differential will result in too large pressure or temperature oscillations. Question: Is it possible to use Danfoss pressure switches when the medium is oxygen?    Answer: As it is not possible for Danfoss to guarantee a bellow element that is free of oil, we advise customers not to use oxygen together with Danfoss pressure switches. In principle, our pressure switches will work well with oxygen if the parts in contact with the medium are totally free of oil. If there is oil, there will be an explosion risk. Question: I need a spare part for my product. Do you have that?    Answer: Please see the relevant accessories sections in our internet product catalogue, which will list all available spare part options for your market. Question: Is it possible to replace the diaphragm on the CS pressure switch?    Answer: It is not possible. You will have to buy a new CS. Question: How can the differential in RT controls be adjusted?    Answer: To set a differential in RT unit, please use the diagram that can be found in customer instruction. The diagram shows which digit should be set at the differential setting disc to obtain required differential. The input to the diagram is differential range and neutral zone, which gives the setting position on the setting disc. Question: What does it mean that RT switches have “fail-safe function”?    Answer: A switch is fail-safe if it has capability to remain in safe condition or transition to a safe condition when a fault occurs. RT pressure switches have double bellows – external and internal. The double bellows system prevents loss of charge in the event of bellows rupture. A rupture in the inner bellows will cause the control pressure to fall about 3 times less than the pre-set value and the compressor will stop. A rupture in the outer bellows will cause the control cut-out pressure to fall to about 3 bar under the pre-set value, thus providing a fail-safe function. Question: What does it mean that an RT switch has an IP66 grade?    Answer: IP is a classification of enclosure grades. It contains 2 digits. The first digit indicates the degree of enclosure against foreign bodies and the second one indicates the degree of water tightness. IP66 means that a wire of 1 mm diameter and dust cannot enter, and that the enclosure will withstand water jets from all directions, 100 l/min. Question: Are the pressure switches KP, KPI and KPS suitable for liquid media?    Answer: KPI and KPS switches are recommended for liquid media. KP can be used with liquid media when a direct pressure connection of 6 mm or higher are used. Question: After installing the switch and making the setting based on scale values, the real system pressure value and scale value seem not to correspond. What is the reason?    Answer: Scale values are indicative only and for accurate settings a pressure gauge (for pressure switches) or a thermometer (for temperature switches) must be used. Question: Which types of pressure switches have Pressure Equipment Directive (PED) approval?    Answer: All BCP pressure switches have the PED approval, and the RT pressure swiches for steam plant with the measuring range 0-25 bar are also appoved. Question: 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 Question: 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. Question: I am looking for the on/off switch with the highest possible IP protection, what options do I have?    Answer: KPS and CAS pressure and temperature switches has the highest IP protection - IP67. Question: What does "proportional working principle" mean for KPI pressure switches?    Answer: "Proportional working principle" means that changes of the pressure in the system are directly translated into movement of the bellows element – the bellows element is continuously “moving” depending on the system pressure. Question: Which on/off pressure switch has the highest vibration resistance?    Answer: The MBC pressure switch has the highest vibration resistance, with maximum permissible vibration level of 20g. Question: What is the maximum pressure range for the MBC switches?    Answer: MBC switches operates up to 400 bar, making them especially suited for hydraulic applications. Question: How does the manual reset work in relation to on/off switches?    Answer: After cut out operation, the unit (pressure or temperature switch) will not cut in until the reset button is manually activated. Question: For the RT pressure switches, what do the letters A, W, B and S in the type designation mean?    Answer: A: Units suitable for the medium ammonia W: Units for control purposes B: Safety units with external reset S: Safety units with internal reset Question: Does Danfoss offer special pressure switches suitable for steam boiler applications?    Answer: BCP and RT pressure switches are available with safety PED approval. Question: What is differential setting (pressure or temperature)?    Answer: The differential pressure or temperature setting is the difference between cut-in and cut-out pressure or temperature level. Question: Does Danfoss offer special pressure switches suitable for sea water as medium?    Answer: Yes, KPS 43, 45 or 47 diaphragm versions are suitable for sea water as medium. Question: How can I protect an installed MBC switch against excessive pressure peaks?    Answer: To protect against pressure peaks (e.g. in a lubrication oil system), mount a pulse snubber, available as an accessory from Danfoss. Question: What does SPDT stands for?    Answer: Single Pole Double Throw refers to the type of the contact system. Question: What is the most common contact system type used in Danfoss switches?    Answer: The SPDT (Single Pole Double Throw) contact system is the most used. Question: Which is the best choice among pressure switches for marine applications with high pulsating media?    Answer: Pressure switches with a diaphragm type of sensor (types MBC, KPS, CAS) are the most capable for systems where high pulsations occur. When such pulsations are present, a damping device or pulse snubber should be considered. Question: Is it possible to improve the IP enclosure grade for KP switches?    Answer: Yes, it can be upgraded to IP55 - using the transparent or non-transparent enclosure (both sold as accessories). Question: What would be the best pressure switch choice for applications requiring high repeatability, accuracy and adjustable differential?    Answer: RT switches used for regulation, monitoring and alarm purposes feature the highest repeatability and accuracy. They are also available with adjustable differential. Question: What is the difference between MBC 5000 and MBC 5100 switches?    Answer: MBC 5100 switches are specifically developed for marine applications and feature ship approvals. Question: When is it recommended to use a gold-plated contact system?    Answer: Gold plated contacts are particulary suitable for low voltage contol systems. Question: What is the key difference between KPS and CAS switches?    Answer: KPS is equipped with a contact system, and has adjustable differential. The CAS has a microswitch and differential is fixed, meaning differential value cannot be adjusted. Question: 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/ Question: I am looking for a Danfoss product, type USC6000, but cannot find it in your catalogues?    Answer: This product type was previously a part of Danfoss Analytics, and is now part of the company Hach Lange. Question: 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. Question: Do you have a pressure switch for steam applications, PED approved?    Answer: You should order the new BCP switch with TÜV approval or the the RT TÜV versions, constructed especially for boiler applications. Question: I am looking for a pump, type APP?    Answer: This product is marketed by Danfoss High-Pressure Systems (Nessie); please see contact options here: http://www.danfoss.com/BusinessAreas/High-Pressure+Systems/Nessie+Worldwide.htm Question: Can I order the membrane for the CAS 155 as a spare part?    Answer: No, unfortunately you need to order a new pressure switch. Question: What kind of pressure switch can I choose for a water pump?    Answer: Our CS and KP/KPI are commonly used in this application, depending on other specifications that you have. Be aware that the pressure connection for the KP must be min. 6 mm. Question: Where I can find technical information regarding on/off switches?    Answer: In our internet catalogue you can see all relevant product data, as well as download literature and approvals for the specific products. Question: What is the material of ¼ in. flare connector in KP pressure switches?    Answer: The connector is made of free cutting steel with nickel plating. A new version made of stainless steel is also available upon customer request. Question: Can a RT262AL pressure switch be used with water?    Answer: Yes, the RT262AL can be used with water, however it is primarily designed for ammonia. For use exclusively with water we have other RT options; please see our internet product catalogue. Question: How many cycles can KP switches perform?    Answer: Units are taken from current production for life tests, electrical and mechanical. The tests are carried out under the most severe conditions. The mechanical life time test has to fulfill at least 400,000 cycles – the average is 1,000,000 cycles. The electrical life time test has to fulfill at least 100,000 cycles (under full load) – the average is 400,000 cycles. Question: Can I seal the setting of a KP pressure switch?    Answer: Danfoss offers a special sealing for the KP range. The code no. for this accessory is 060-105766. Each package contains 20 pcs. of screws. Question: What is the scale accuracy of the KP switches?    Answer: Scale values are indicative only and it is recommended to use a pressure gauge when setting working points. The scale accuracy in case of KP is +/- 10% of the max. range (adjustable units) and +/- 5% of the max. range in case of factory-set units. Question: I am looking for Danfoss MASSFLO and MAGFLO flow meters?    Answer: This product type was previously a part of Danfoss Flow Division, and is now part of the company Siemens. Question: I am looking for a Danfoss butterfly valve?    Answer: This product is marketed by Danfoss Water Controls; please see contact options here: http://www.danfoss.com/BusinessAreas/Water+Controls/ Question: Do I need an external power supply for RT switches?    Answer: No, our RT range of temperature and pressure switches operate without external power supply. The switching force comes from the bellows. It works with an SPDT switch over contact. Question: Can you deliver your products wordwide?    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/ Question: 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. Question: 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. Question: 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. Question: 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. Question: 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 avaliable items. Question: 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. Question: 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 perfomance for our customers. Question: 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 Question: 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. Question: 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/ Question: Can you give me some key figures on danfoss?    Answer: If you are looking for number of employees, sales companies, turnover etc., you will find updated information here: http://www.danfoss.com/AboutUs/FactsAndFigures/ Question: 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. Question: Is Danfoss a German company?    Answer: No, it is a globally acting group with headquarters in Denmark. Question: I am looking for a hydraulic oil pump?    Answer: Hydraulic oil pumps are part of the product programme of the separate company Sauer-Danfoss. Question: Is it possible to order an MBC with short cable and special plug (different then DIN plug)?    Answer: Yes, we have many options outside our standard programme - please contact Danfoss to specify your needs. Question: Do you offer pressure switches in stainless steel?    Answer: Yes, such a design is possible for the KP and KPI types. Please contact Danfoss to specify your needs. Question: What is the procedure for setting an MBC pressure switch?    Answer: 1. Secure regulated pressure source with pressure gauge and state indicator for electric connector of MBC. 2. Connect the unit to pressure source and electrically to indicator. 3. Change pressure slowly and observe indicator. 4. Note down upper and lower snap point pressure. 5. If necessary, turn range screw to change setting and repeat 3. and 4. 6. Mount in the final application. 7. Verify settings with pressure gauge and indicator in the application. 8. If necessary do small adjustments. 9. Good practice - Note settings and date on the small card attached to switch. Inspect setting once in a while. Note inspection results on the same card. Keep track of abnormal events: Other elements breakdowns, servicing etc. Question: Is a bellows-type pressure switch better than a diaphragm-operated one?    Answer: It depends on your need. Diaphragm versions (if units are of the similar size) are more resistant to pressure pulsation and fluid hammering. They are also better for media with particles or sediments. However, usually diaphragm versions have higher differential and lower repeatability. Question: Do we have device for measurement of liquid level of a open tank?    Answer: A very good solution is RT 113, equiped with external pipe for liquid level up to 3 m, while differential could me measured from 10 to 50 cm. Question: Can I use RT or other pressure switches in steam applications?    Answer: Depending on the temperature you have to use a steam trap in order to create a natural sealing with the water in the system. Normally you can use RT up to 80 °C. and BCP up to 120 °C. Question: How do I set up the differential on a CS pressure switch?    Answer: In our technical brochure, you will see the number of turns you have to make by using a screw driver in order to reach the right value. The brochure can be downloaded from our web catalogue. Question: I am looking for a simple pressure switch to start up my 3-phase compressor - which one should I take?    Answer: We recommend the CS series which is available in IP43 and IP55 versions, and which has 3-pole contacts. Question: Can you confirm that Danfoss does not use "deca-BDE" for pressure switches?    Answer: Our products (including pressure switches) are covered by RoHS Directive and meet its requirements. This directive bans using some hazardous substances, e.g. PBDE (polybrominated diphenyl ethers) and PBB (polybrominated biphenyls). PBDE and PBB were used as flame retardants in plastic parts. There is no PBDE in our products. Question: Can I use the RT pressure switch type RT 112 with bio-mass fuel?    Answer: You can not use this RT switch in such an application because hydrogen sulfide will affect the material for the RT bellows. A stainless steel version should be used instead. Question: Why is our delivery delayed, when I saw that the delivery date is confirmed for 2 weeks in e-commerce?    Answer: Reasons for late delivery could be production problems from Danfoss or incompliance with the payment terms from your side. You can always check the status of your order on our e-business system to see updated confirmation date or a message to contact Danfoss in case of late payment. Question: 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 Question: Does Danfoss have a product for controlling the vacuum in a vacuum pump?    Answer: Yes, the RT 121 pressure switch should be perfect for your need. Question: Do you have pressure switches with "GOST" approvals for the Russian market?    Answer: No longer. We had in the past, but since CE marked units are now accepted, GOST is no longer required. Question: Is it possible to recognize if a RT has "double" bellows installed, from just looking at it from outside?    Answer: Yes, there is one feature that enables you to recognize that the RT has double bellows; a nut (key 32 mm) on the pressure connection. Question: What do I need to know to select the right product?    Answer: The following are the basics for most products used in industrial environments: Application - Pressure - Temperature - Medium - Connection Question: Can I get quality control plans/process flowcharts/material specifications/FMEA for Danfoss products?    Answer: No, this is confidential information which cannot be shared outside Danfoss. Rare exceptions are cases of special legal agreements between Danfoss and the other company. Question: Do Danfoss pressure switches feature UL, CSA and ETL certificates?    Answer: Our KP switch is made especially for the North American boiler market. This product range has special versions with UL and can be enclosed in IP55 cover. Our BCP and RT switches do not have UL/CSA or ETL approvals. Question: 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 ia@danfoss.com, describing your interest and application. Question: 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. Question: How can I monitor when I have to change the element of my filter?    Answer: Please use our differential pressure switch; take the inlet and outlet pressure of the filter. When the element is saturated the pressure will increase and the switch will turn on, warning you. Question: Can I download product approvals & certificate from the Danfoss websites?    Answer: Yes, in our internet product catalogue, all product approvals & certificates are listed. If you are unable to local a specific document, please e-mail or call us. Question: Is a pressure switch' differential and a differential pressure switch the same?    Answer: No, the differential of the pressure switch is an option that you have in a switch to set individually cut-in and cut-out difference. A differential pressure switch is a switch that has two seperate pressure inputs and act on this difference. Question: Is it possible to buy just the contacts for the RT switches?    Answer: Yes, please see our internet product catalogue for options in spare parts & accessories. Question: Which media can Danfoss products be used with?    Answer: The answer depends on the materials in contact with medium for the particular product. This information can be found in the technical brochure / data sheet for the product. We have products designed specifically to handle particular media, including drinking water, oil, air, petrol, steam and more. If in doubt, please contact your nearest Danfoss office. Question: Which switches should I use for seawater - or other media with particles or depositions?    Answer: In case of seawater you should generally use diaphragm versions of switches: - KPS 43, 45 & 47 - CAS 143, 145 & 147 - MBC 5100 with diaphragms Seawater may contain contamination and certainly salt, both of which will likely accumulate inside the application. Not least inside the switch,, because the water inside is almost still (no flow). If salt crystallizes on the bellows surface it can easily affect its proper function. In case of diaphragms, very smooth and flexible, this problem is less visible. This will cause the depositions to be removed from its surface, and until the whole system is filled and blocked with depositions, it will work. Depositions are especially dangerous when you have a small bellows - like in MBCs. If you need to use bellows version of switches then try to choose comparatively big bellows - surfaces on which depositions are stored are comparatively far away and it would take a longer time before they affect bellows function. RT is a switch of this kind. Question: Where do I find production date on pressure or temperature switches?    Answer: Look for a code similar to the below: AB - identifies factory location (in this case, Poland) 29 - first two digits tell you production week 6 - last digit tells you about production year (2006) Question: Can Danfoss adjust the differential in a MBC?    Answer: No it is not possible; the differential in an MBC cannot be set. Question: For the Pg plugs sold with MBC, which are the recommended cable diameter sizes?    Answer: Cable diameter should be: Pg9: 6-8 mm Pg11: 8-10 mm Pg13.5: 10-14 mm This is valid only for plugs used with MBC products.