Burkert Type 8625 User Manual download pdf (Page 34)

32 - 8625-2 Standard

english

6.6.7

ZERO

- zero point switch-off

No zero point switch-off (

The control is continuous down to the lower limit, i.e. until the

minimum pulse-duty ratio set in the menu item „VALC“ is

reached. The valve is closed but usually not leak-free.

Preconditions for zero

• Zero point switch-off (YES) has been selected;

• The setpoint is less than 2 %;

• Non-inverted control.

Zero point switch-off enables the proportional valve to assume a tight-closing

function in addition to the control function.To obtain tight closure when the set point

is 0, at set points below 2% of the overall range, no signal is sent to the valve, so

that the entire spring force is available for tight closure. The lower 2% of the set

point range is hence not available for control purposes.

Without zero point switch-off, a signal is sent to the valve also when the set point

is 0. This signal generates just enough magnetic force for the start of opening. This

acts in opposition to the spring force, so that the valve is not perfectly tight in most

cases.

(works setting: NO)

Zero point switch-off (

YES

The control is continuous until the input signal has reached a

value of less than 2%, then the valve will be closed.

Fig.: Zero point switch-off

1 2 ... 29 30 31 32 33 34 35 36 37 38 39 ... 117 118

No comments

Burkert Type 8625 User Manual Page 34