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Differential pressure switches
Technical data
Differential
Operation
Mechani-
pressure
range for
range ∆p
Type
LP bellows
[bar]
[bar]
RT 260A
0.5 – 4
-1 – 18
RT 260A
0.5 – 6
-1 – 36
RT 260A
1.5 – 11
-1 – 31
RT 262A
0.1 – 1.5
-1 – 9
RT 265A
1 – 6
-1 – 36
RT 260AL
0.5 – 4
-1 – 18
RT 262AL
0.1 – 1.5
-1 – 9
RT 263AL
0.1 – 1.0
-1 – 6
RT 266AL
0 – 0.9
-1 – 6
Neutral zone, ∆p Nz
RT 260AL: 0.3 bar – 0.9 bar
RT 262AL: 0.1 bar – 0.33 bar
RT 263AL: 0.05 bar – 0.23 bar
RT 266AL: 0.05 bar – 0.23 bar
Max. test pressure, p' = 1.1 × MWP
Permissible temperature range:
-40 °C – 70 °C
Contact load
See contact cover or fig. 3.
If the contact load is given as, for example,
10 (4) A, 400 V AC, it means that the
connected load must be max. 10 A ohmic and
4 A inductive at 400 V AC.
The permissible starting current on motor
cut-in can be up to seven times the inductive
load, but max. 28 A.
The switch meets the requirements of
VDE* 0660.
*VDE = Verband Deutscher Elektrotechniker
Installation
A set of Pg13.5 cable gland is attached to the
RT in a separate bag. To ensure IP66 (units
with automatic reset) or IP54 (units with
external reset) grade of RT enclosure it is
necessary to assemble this gland as shown in
the fig. 4. If this gland is not used with a cable,
a metal blinding should be also assembled.
The differential pressure control must be
mounted on a valve panel or, for example,
direct on a compressor. Use the fixing holes
(25). If the unit can be exposed to vibration, it
should to be mounted on a resilient pad.
Electrical connection
See fig. 5.
START = make. STOP = break
DIFF = fixed contact differential
Cable diameter: 6 – 14 mm
Connect earth to the earth screw (38)
Setting
Set the required differential pressure with the
setting disc (5) while at the same time reading
the scale (9). Find the required neutral zone
for RT 260AL, RT 262AL, RT 263AL, RT 266AL
from the diagram. The setting value for the
© Danfoss | DCS (jmn) | 2015.11
neutral zone (40) can be read from the lowest
scale on the diagram.
Example 1
RT 262A with terminals 1 – 4 connected. Set
differential pressure ∆p = 0.5 bar.
Max.
cal
working
The RT 262A breaks at a differential pressure
differen-
pressure
of 0.5 bar and makes at a differential pressure
tial
MWP
+ contact differential = 0.5 bar + 0.1 bar = 0.6 bar.
[bar]
[bar]
0.3
22
Example 2
0.5
42
RT 262AL
0.5
42
Required differential pressure ∆p = 0.5 bar.
0.1
11
Required neutral zone Nz = 0.25 bar.
0.5
42
As can be seen on the diagram, fig. 6., the
0.3
22
required neutral zone of 0.25 bar is obtained
0.1
11
by setting the neutral zone disc (40) at 2.5.
0.05
7
Because the contact differential is 0.1 bar, the
0.05
7
make and break differential pressures for the
switch are:
Make differential pressure for contacts
1 – 4 = 0.5 bar + 0.1 bar = 0.6 bar.
Break differential pressure for contacts
1 – 4 = 0.5 bar (= set value ∆p).
Make differential pressure for contacts
1 – 2 = 0.6 bar – 0.25 bar = 0.35 bar.
Break differential pressure for contacts
1 – 2 = 0.35 bar + 0.1 bar = 0.45 bar.
Differenspressostater
Tekniske data
Type
RT 260A
RT 260A
RT 260A
RT 262A
RT 265A
RT 260AL
RT 262AL
RT 263AL
RT 266AL
Neutralzone, ∆p Nz
RT 260AL: 0.3 bar – 0.9 bar
RT 262AL: 0.1 bar – 0.33 bar
RT 263AL: 0.05 bar – 0.23 bar
RT 266AL: 0.05 bar – 0.23 bar
Maks. prøvetryk, p' = 1.1 × PB
Tilladelig temperatur: -40 °C – 70 °C
Kontaktbelastning
Se kontaktdæksel eller fig. 3.
Er kontaktbelastningen eksempelvis angivet
som 10 (4) A, 400 V AC betyder det, at der
maks. må tilsluttes 10 A ohmsk og 4 A
induktiv belastning ved 400 V AC Maksimal
startstrøm ved indkobling af motor må være
op til syv gange den induktive belastning –
dog maks. 28 A.
Kontaktsystemet opfylder betingelserne i
*VDE = Verband Deutscher Elektrotechniker
Montering
Et sæt Pg13,5 kabelforskruning er vedlagt
DANSK
Differens-
Driftsom-
Mekanisk
trykområde
råde for
differens
ladeligt
∆p
LP-bælg
drifts-
tryk PB
[bar]
[bar]
[bar]
0.5 – 4
-1 – 18
0.3
0.5 – 6
-1 – 36
0.5
1.5 – 11
-1 – 31
0.5
0.1 – 1.5
-1 – 9
0.1
1 – 6
-1 – 36
0.5
0.5 – 4
-1 – 18
0.3
0.1 – 1.5
-1 – 9
0.1
0.1 – 1.0
-1 – 6
0.05
0 – 0.9
-1 – 6
0.05
produktet i en separat pose. For at sikre
kapslingsgrad IP66 (enheder med automatisk
reset) eller IP54 (enheder med ekstern
DANSK RESET) er det nødvendigt at montere
denne kabelforskruning som vist i fig. 4.
Hvis denne kabelforskruning ikke bruges
sammen med et kabel, bør der monteres
en blindprop (metal skive).
Differenspressostaten monteres på en ventilt-
avle eller f.eks. direkte på en kompressor.
Benyt monteringshullerne (25).
Hvis apparatet kan blive udsat for vibrationer,
bør det monteres på et blødt underlag.
El-tilslutning
Se fig. 5.
START = slutte. STOP = bryde DIFF = fast
kontaktdifferens.
Kabeldiameter: 6 – 14 mm.
Jordforbindelse tilsluttes jordskruen (38).
Indstilling
Det ønskede differenstryk indstilles ved
hjælp af indstillingsskiven (5) under samtidig
aflæsning af skalaen (9).
Den ønskede neutralzone for RT 260AL,
RT 262AL, RT 263AL, RT 266AL opsøges i
diagrammet. På diagrammets nederste skala
aflæses den værdi, neutralzonerullen (40) skal
indstilles på.
Eksempel 1
RT 262A med klemme 1 – 4 tilsluttet.Indstillet
Til-
differenstryk ∆p = 0.5 bar.
RT 262A bryder ved differenstrykket
0.5 bar og slutter ved differenstrykket +
[bar]
kontaktdifferensen = 0.5 bar + 0.1 bar = 0.6 bar.
22
42
Eksempel 2
42
RT 262AL
11
Ønsket differenstryk ∆p = 0.5 bar.
Ønsket neutralzone Nz = 0.25 bar.
42
Som det kan ses af diagrammet fig. 5., opnås
22
den ønskede neutralzone på 0.25 bar ved at
11
indstille neutralzonerullen (40) på værdien 2.5.
7
Slutte- og brydedifferenstrykkene for
7
kontaktsystemet (se fig. 4.) bliver herved, idet
kontaktdifferensen er 0.1 bar:
Sluttedifferenstryk for kontakterne
1 – 4 = 0.5 bar + 0.1 bar = 0.6 bar.
Brydedifferenstryk for kontakterne
1 – 4 = 0.5 bar (= indstillingsværdi, ∆p).
Sluttedifferenstryk for kontakterne
1 – 2 = 0.6 bar – 0.25 bar = 0.35 bar.
Brydedifferenstryk for kontakterne
1 – 2 = 0.35 bar + 0.1 bar = 0.45 bar.
DKRCC.PI.CE0.B1.53 | 520H4221 | 2
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