Float switches are switching devices operated by a float moved by fluid. These are used to control fluid levels in power unit tanks.
Three series are available:
- Float switches type …M consisting of a breathing filter, level monitoring (max./min.) and temperature measurement and display with two adjustable alarm outputs
- Float switches type …N consisting of a breathing filter, level monitoring (max./min.) and temperature measurement with one contact
- Float switches type …R consisting of a breathing filter, a resistance measuring chain for level, a resistance thermometer for temperature with analog output from 4 to 20 mA and an analog temperature display
Float switch type …M
Tank venting function
Breather filter with filtration rating of 3 µm absolute.
The visual analog clogging indicator shows the increase in the degree of contamination of the filter element in percent.
Level switch function
Two reed contacts are provided in the sliding tubes (normally closed contact and normally open contact), which are switched by the permanent magnet installed in the float.
When the float reaches the switching points while the oil level is falling, the contacts are operated by magnetic force. The positions of the contacts are maintained until the float passes the switching points again when the oil level is rising.
The switching points are factory-set (for values, see “Oil volume indication”).
As a standard, switching point L1 is installed as a normally closed contact, and switching point L2 as a normally open contact.
The switching points can be adjusted within the device (for instructions, see “Oil volume indication”).
The switching function can be changed by rotating the contacts through 180°, the normally closed contact becomes a normally open contact and vice versa.
Temperature display
The current temperature is shown on a clearly visible LED display, which also signals status messages. The temperature is displayed in °C or °F.
Temperature signal function
Temperature is sensed by a PT 100.
The two temperature signals can be adjusted by means of the three keys provided on the control device.
The settings are protected against unauthorized access through programming guidance (see “Commissioning – operating and installation instructions”).
Float switch type …N
Tank venting function
Breather filter with filtration rating 3 µm absolute.
The visual analog clogging indicator shows the increase in the degree of contamination of the filter element in percent.
Level switch function
Two reed contacts are provided in the sliding tubes (normally closed contact and normally open contact), which are switched by the permanent magnet installed in the float.
When the float reaches the switching points when the oil level is falling, the contacts are operated by magnetic force. The positions of the contacts are maintained until the float passes the switching points again when the oil level is rising.
The switching points are factory-set (for values, see table on “Oil volume indication”).
As a standard, switching point L1 is installed as a normally closed contact, and switching point L2 as a normally open contact.
The switching points can be adjusted within the device (for instructions, see “Oil volume indication”).
The switching function can be changed by rotating the contacts through 180°, the normally closed contact becomes a normally open contact and vice versa.
Temperature signal function
Temperature is sensed by a PT 100.
A bimetal plate, which is influenced by temperature, switches when the firmly set response temperature is reached.
Float switch type …R
Tank venting function
Breather filter with filtration rating 3 µm absolute.
The visual analog clogging indicator indicates the increase in the degree of contamination of the filter element in percent.
Level switch and temperature signal function
The sliding tube accommodates the resistance measuring chain with a resolution of 7.5 mm for continuous monitoring of the fill levels.
Permanent magnets installed in the float switch the contacts and activate a resistance.
The resistance thermometer (PT100) for temperature sensing is also integrated in the sliding tube.
A measuring transducer, which is integrated in the connected housing, converts the level- and temperature-related signal into a linear current change of 4 to 20 mA.
Temperature display
A clearly visible LED display indicates the current temperature.
The temperature is shown in °C or °F (how to change the indication is described at “Commissioning – operating and installation instructions”).