Product Overview

Data sheet | Pressure switch, KP
DKRCC.PD.CD0.1A.02 | 520H11562 | 8
Terminology Reset
1. Manual (Min. / Max.) reset:
Units with manual reset can only be reset
during operation by activation of the reset
button
2. Automatic reset:
After operational stop, these units reset
automatically
3. Convertible reset:
Units with optional reset can be activated by
automatic and/or manual reset
Permissible working pressure
The permissible working pressure is determined
by the pressure that can be safely allowed in the
refrigerating system or any of the units within it.
Test pressure
The test pressure is the pressure used in strength
tests and/or leakage tests on refrigerating
systems or individual parts in systems. The test
pressure is designated P
e
.
Pressure switches with automatic reset – LP:
Set the LP start pressure on the "CUT-IN" scale
(range scale). One rotation of the low pressure
spindle ∼ 0.7 bar.Set the LP dierential on the
"DIFF" scale. One rotation of the dierential
spindle ∼ 0.15 bar.The LP stop pressure is the LP
start pressure minus the dierential.
Note:
The LP stop pressure must be above absolute
vacuum (P
e
= -1 bar)!
If with low stop pressure the refrigeration
compressor will not stop, check to ensure that
the dierential value has not been set too high!
“Snap function”
A certain contact force is maintained until
irrevocable “snap” is initiated. The time during
which the contact force approaches zero is thus
limited to a very few milliseconds. Therefore
contact bounce cannot occur as a result of, for
example, slight vibrations, before the cut-out
point. Contact systems with “Snap function” will
change over even when micro-welds are created
between the contacts during cut-in. A very high
force is created during cut-out to separate the
contacts. This force immediately shears o all the
welds. Thus the cut-out point of the unit remains
very accurate and completely independent of
the magnitude of the current load.
Pressure switches with automatic reset – HP:
Set the HP pressure on the “CUT-OUT” scale.
One rotation of the HP spindle ∼ 2.3 bar.
Set the HP dierential on the “DIFF” scale.
One rotation of the dierential spindle ∼ 0.3 bar.
The HP start pressure is the HP stop pressure
minus the dierential.
Start and stop pressures for both the LP and HP
sides of the system should always be checked
with an accurate pressure gauge.
Pressure switches with manual reset
Set the stop pressure on “CUT-OUT” scale
(range scale).
Low pressure switches can be manually reset
when the pressure is equal to the stop pressure
plus the dierential.
High pressure switches can be manually reset
when the pressure is equal to the stop pressure
minus the dierential.
Setting
© Danfoss | DCS (rm) | 2019.03