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What is the neutral band?
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The neutral band is common to a particular series of RT switches and are 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.
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What is the maximum/minimum pressure/temperature at which Danfoss switches can be set?
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Danfoss manufacture various pressure switches which can have a setting range of anywhere between -1 to 100 bar and the thermostats 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.
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What is the maximum/minimum your pressure/temperature sensors can measure?
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What is the maximum/minimum your pressure/temperature sensors can measure?
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Are Danfoss Pressure Switches affected by the new Pressure Equipment Directive (PED)?
The Pressure Equipment Directive (PED) is an EU Directive which becomes mandatory on the 29th May 2002. The Directive dictates that safety equipment be CE marked and approved by a notified body. In order to satisfy this requirement Danfoss offer the following range of PED compliant Safety Pressure Switches.
Click here to download document with CE marked pressure switches
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How do you wire the neutral on the pressure switch or thermostat?
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You do not wire the neutral on a Danfoss switch, only the live. The only time you need a neutral is when you have a thermostat with an 'accelerator', which is a built-in heater and is uncommon in industrial switches but common in domestic thermostats.
If you are unsure of how to wire up the switch, please contact a qualified electrician or call the Danfoss Controls Technical Support team on: 0870 241 7010.
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Why do you not make a thermo-pocket which is short enough for me to fit into my pipeline?
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Please see the relevant pages relating to the temperature sensor you are interested in. However, a common practice is to place the sensor at the bend in the pipe work so that the thermo-pocket sticks down one of the pipes.
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Can the pressure / temperature switch operate on its own or do I need to buy other things?
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You may need one of our contactors if you are switching heavy loads such as a heater. Please check the current rating of the switch you are interested in. A thermo-pocket may also be a good idea for the thermostats if you are placing the sensor into a tank or pipeline. This will allow the switch to be replaced at a later date without much disruption to the system. The pressure switches may also need additional fittings to connect to pipe work. Please see the accessories pages relevant to each product.
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What is the DIN numbering of terminals?
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Terminal numbers are always ODD for inputs & EVEN for outputs, which explains why the changeover switch in almost all pressure switches & thermostats 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) and 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).
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I need a spare for the RT (or KP/KPI). Do you have that?
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Please see the relevant accessories page within the product catalogue, if we do not list an accessory then it will not be available.
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What is differential?
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The differential is the difference between a switch cutting in and cutting out. A common example of differential can be found with a domestic kettle. After it has boiled and switched off, you can not switch it on again until it 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.
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