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.
In my application there are pulsations. Which pressure switch should I choose?
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.
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.
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).
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.
I need a spare part for my product. Do you have that?
Is it possible to replace the diaphragm on the CS pressure switch?
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.
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.
Are the pressure switches KP, KPI and KPS suitable for liquid media?
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?
Which types of pressure switches have Pressure Equipment Directive (PED) approval?
Where can I find approvals and certificates for Danfoss products? E.g. do you have a PED certificate for KP7W?
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.
I am looking for the on/off switch with the highest possible IP protection, what options do I have?
What does "proportional working principle" mean for KPI pressure switches?
Which on/off pressure switch has the highest vibration resistance?
What is the maximum pressure range for the MBC switches?
How does the manual reset work in relation to on/off switches?
For the RT pressure switches, what do the letters A, W, B and S in the type designation mean?
Does Danfoss offer special pressure switches suitable for steam boiler applications?
Does Danfoss offer special pressure switches suitable for sea water as medium?
How can I protect an installed MBC switch against excessive pressure peaks?
What does SPDT stands for?
What is the most common contact system type used in Danfoss switches?
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.
Is it possible to improve the IP enclosure grade for KP switches?
What would be the best pressure switch choice for applications requiring high repeatability, accuracy and adjustable differential?
What is the difference between MBC 5000 and MBC 5100 switches?
When is it recommended to use a gold-plated contact system?
What is the key difference between KPS and CAS switches?
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?
Do you have a pressure switch for steam applications, PED approved?
Does Danfoss offer products with ATEX certificate (EEx)?
Answer: Yes, you can order solenoid coils, switches, pressure transmitters and temperature sensors with this approval.
What kind of pressure switch can I choose for a water pump?
Where I can find technical information regarding on/off switches?
What is the material of ¼ in. flare connector in KP pressure switches?
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.
Can I seal the setting of a KP pressure switch?
What is the scale accuracy of the KP switches?
Do I need an external power supply for RT switches?
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?
Can I review your stock online?
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.
Where do I direct commercial or technical questions?
Do you have local stock?
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?
Is it possible to place orders online?
Does Danfoss operate globally?
Is Danfoss a German company?
Do you offer pressure switches in stainless steel?
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.
Is a bellows-type pressure switch better than a diaphragm-operated one?
How can I connect a solenoid valve with a pressure/temperature switch?
Do we have device for measurement of liquid level of a open tank?
Can I use RT or other pressure switches in steam applications?
How do I set up the differential on a CS pressure switch?
I am looking for a simple pressure switch to start up my 3-phase compressor - which one should I take?
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.
Can I use the RT pressure switch type RT 112 with bio-mass fuel?
Where can I find some technical information about your products?
Does Danfoss have a product for controlling the vacuum in a vacuum pump?
Do you have pressure switches with "GOST" approvals for the Russian market?
Is it possible to recognize if a RT has "double" bellows installed, from just looking at it from outside?
What do I need to know to select the right product?
Can I get quality control plans/process flowcharts/material specifications/FMEA for Danfoss products?
Do Danfoss pressure switches feature UL, CSA and ETL certificates?
Can you send me literature, brochures or catalogues on your products?
I placed an order through e-commerce. Could you please check the delivery dates and inform me the earliest possible delivery?
How can I monitor when I have to change the element of my filter?
Does Danfoss provide a solution for pressure control of screw compressors?
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.
Is it possible to buy just the contacts for the RT switches?
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.
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.
Where do I find production date on pressure or temperature switches?