Function and configurationHydro-electric pressure switches type HED 8 are piston type pressure switches.They basically consist of the housing (1), cartridge with spool (2), compression spring (3), adj...
Product Detail
Function and configuration
Hydro-electric pressure switches type HED 8 are piston type pressure switches.
They basically consist of the housing (1), cartridge with spool (2), compression spring (3), adjustment element (4) and micro-switch (5).
If the pressure to be monitored is below the set value then the micro-switch (5) is actuated. The pressure fluid is applied to the piston (2) via orifice (7). The piston (2) supports itself on the spring seat (6) and acts against the infinitely adjustable force of the compression spring (3). The spring seat (6) transfers the movement of the piston (2) to the micro-switch (5). The micro-switch (5) is released when fluid setting pressure is reached.
The electrical circuit is either switched on or off according to the circuit design. The mechanical stop of the spring seat (6) protects the micro-switch (5), in the case of sudden pressure loss, from mechanical destruction and prevents the compression spring (3) from damaging if an over-pressure occurs.
Note:
To increase the service life,
the pressure relay should:
switch should be mounted vibration-proof
protected from hydraulic pressure shocks.
Ordering code
Characteristic curves(Measured at oil=40°C +5°C,using HLP46)
Technical data
| Weight | -Pressure switch | kg | 0.8 | ||
| - Sandwich plate for vertical stacking assemblies | kg | 0.8 (NS 6, plate height 40.5mm) | |||
| 3 (NS 6, plate height 120 mm) | |||||
| 2 (NS 10) | |||||
| Fluid | Mineral oil suitable for NBR and FKM seal | ||||
| Phosphate ester for FKM seal | |||||
| Fluid temperature range | ℃ | -20 to+80 (for FKM seals) | |||
| -30 to+80(for NBR seals) | |||||
| Viscosity range | m㎡/s | 2.8 to 500 | |||
| Degree of contamination | Maximum permissible degree of fluid contamination: Class 9. NAS 1638 or 20/18/15, ISO4406 | ||||
| Switching accuracy (repeatabiity) | <±1% of setting range | ||||
| Permissible switching frequency | times/min. | 80 | |||
| Pressure setting range | bar | Pressure rating (Max.setting pressure) | Max.operating pressure | Pressure setting range | |
| 50 | 350 | 2 to 50 | |||
| 100 | 350 | 4 to 100 | |||
| 200 | 350 | 5 to 200 | |||
| 350 | 500 | 8 to 350 | |||
| Electrical connection | plug-in connector to DIN 43 650, form A, 3-pin+PE | ||||
| Max. connection cross sectional area | m㎡ | 0.5 | |||
| Max.contact load | -AC | 250V/5A | |||
| -DC | 50V/1A; 125V/0.03A; 250V/0.02A | ||||
| Protection to DIN 40 050 | IP65 | ||||
| With DC inductive loading, a spark suppressor must be provided in order to increase the service life. | |||||
Unit dimensions
Installation guideline
For the pressure switch type HED 8...as a sandwich (350bar)
Ordering code
For the pressure switch type HED 8...as a sandwich (350bar)
Ordering code
Transition plate when pressure switch type HED8OH substitutes HED4OH
Terminal allocation
Circuit example
