© Danfoss | DCS (jmn) | 2015.11
DKRCC.PI.CE0.B1.53 | 520H4221 | 2
Differential pressure switches
Technical data
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
Type
Differential
pressure
range
∆
p
[bar]
Operation
range for
LP bellows
[bar]
Mechani-
cal
differen-
tial
[bar]
Max.
working
pressure
MWP
[bar]
RT 260A
0.5 – 4
-1 – 18
0.3
22
RT 260A
0.5 – 6
-1 – 36
0.5
42
RT 260A
1.5 – 11
-1 – 31
0.5
42
RT 262A
0.1 – 1.5
-1 – 9
0.1
11
RT 265A
1 – 6
-1 – 36
0.5
42
RT 260AL
0.5 – 4
-1 – 18
0.3
22
RT 262AL
0.1 – 1.5
-1 – 9
0.1
11
RT 263AL
0.1 – 1.0
-1 – 6
0.05
7
RT 266AL
0 – 0.9
-1 – 6
0.05
7
Differenspressostater
Tekniske data
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
Type
Differens-
trykområde
∆
p
[bar]
Driftsom-
råde for
LP-bælg
[bar]
Mekanisk
differens
[bar]
Til-
ladeligt
drifts-
tryk PB
[bar]
RT 260A
0.5 – 4
-1 – 18
0.3
22
RT 260A
0.5 – 6
-1 – 36
0.5
42
RT 260A
1.5 – 11
-1 – 31
0.5
42
RT 262A
0.1 – 1.5
-1 – 9
0.1
11
RT 265A
1 – 6
-1 – 36
0.5
42
RT 260AL
0.5 – 4
-1 – 18
0.3
22
RT 262AL
0.1 – 1.5
-1 – 9
0.1
11
RT 263AL
0.1 – 1.0
-1 – 6
0.05
7
RT 266AL
0 – 0.9
-1 – 6
0.05
7
ENGLISH
DANSK
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.
The RT 262A breaks at a differential pressure
of 0.5 bar and makes at a differential pressure
+ contact differential = 0.5 bar + 0.1 bar = 0.6 bar.
Example 2
RT 262AL
Required differential pressure
∆
p = 0.5 bar.
Required neutral zone Nz = 0.25 bar.
As can be seen on the diagram, fig. 6., the
required neutral zone of 0.25 bar is obtained
by setting the neutral zone disc (40) at 2.5.
Because the contact differential is 0.1 bar, the
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.
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
differenstryk
∆
p = 0.5 bar.
RT 262A bryder ved differenstrykket
0.5 bar og slutter ved differenst
kontaktdifferensen = 0.5 bar + 0.1 bar = 0.6 bar.
Eksempel 2
RT 262AL
Ønsket differenstryk
∆
p = 0.5 bar.
Ønsket neutralzone Nz = 0.25 bar.
Som det kan ses af diagrammet fig. 5., opnås
den ønskede neutralzone på 0.25 bar ved at
indstille neutralzonerullen (40) på værdien 2.5.
Slutte- og brydedifferenstrykkene for
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.
