Submittal Sheet

© Danfoss | DCS (rm) | 2019.12 IC.PD.P10.F9.02 | 16
Snap function
A specific contact force is maintained until snap
is initiated. The time over which contact force
reaches zero is a few milliseconds; therefore,
contact bounce cannot occur as a result, for
example, of slight vibrations before cut-out.
The snap-action contact system will continue
to function even when micro-welds are created
between the contacts during cut-in.
The force created to separate the contacts
is strong, and instantly shears off all contact
surface welds that have been created as the
result of cut-in action.
These design features ensure that the cut-out
point of the KP control remains very accurate
and completely independent of the magnitude
of the current load.
Current ratings:
AC – 1
The alternating current rating, in amperes,
of the non-inductive, slightly inductive
loads or resistive furnaces
AC – 3
The alternating current rating, in amperes,
of the squirrel-cage motors: starting,
plugging, inching
AC – 15
The alternating current rating, in amperes,
of electromagnetic loads (>72VA)
DC – 13
The direct current rating, in amperes,
of electromagnets
Range setting / Set point
The pressure range within which the unit
will give a signal (contact changeover).
Differential
The difference between contact changeover
on rising and falling pressure.
The differential is a condition for stable
automatic plant operation.
Manual reset
A unit with manual reset can only
be restored to operational mode by activation
of the external reset button.
Min. reset units will restart after the pressure
has risen by a value greater than that of the fixed
differential.
Max. reset units will restart after the pressure
has fallen by a value greater than that of the fixed
differential.
Automatic reset
Units with automatic reset
restart automatically after stop.
Permissible operating pressure
The highest permissible constant pressure
or pressure variation the unit can be exposed to.
Maximum working pressure
The maximum permissible pressure
for safe functioning of a heating system
or any of its parts.
Maximum test pressure
The maximum pressure applied
in strength or leakage tests on heating
system or components thereof.
Terminology