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> RT, Pressure switches, TÜV approved for steam plant

Switches used in steam plant with TÜV approval

RT, Pressure switches, TÜV approved for steam plant

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17 Item(s)

FAQ

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).
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.
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.
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.
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.
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
What does SPDT stands for?
- Answer: Single Pole Double Throw refers to the type of the contact system.
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.
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.
When is it recommended to use a gold-plated contact system?
- Answer: Gold plated contacts are particulary suitable for low voltage contol systems.
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.
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.
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.
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.
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?
- 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)