Data sheet
Pressure switch, Differential pressure switch and Thermostat
RT-E
The RT-E series consist of pressure
and differential pressure switches as well as
thermostats. The units are designed for industrial
refrigeration and general industrial
explosive zones acc. to 2014/34/EU
explosive zone 1, for surface equipment,
category 2.
It includes usage in refrigeration systems
with ammonia, hydrocarbons and other
applications where presence of flammable gases,
vapours and mists are likely to occur.
RT-E pressure switches and thermostats
for use in explosive zones incorporate SPDT
changeover switch where contact position
depends on pressure or temperature value
of the system.
application in
Atex directive,
Features
Approvals
• Designed for use in explosive zone 1
• Versions with enclosure IP66
• Stainless steel frame
CE marked, according to EN 60947-4/-5
IECEx ULD 14.0013X
DEMKO 14 ATEX 1406X
marking: Ex II 2G Ex ia IIC T6...T1 Gb
CE marked acc. to 2014/68/EU category IV, safety
equipment: RTE6AEW, RTE6AEB, RTE6AES
• Metallized front cover without window
• Gold plated contacts
• Safety Integrity Level:
SIL 2 according to IEC 61508
China Compulsory Certificate, CCC
EAC
© Danfoss | DCS (az) | 2018.03
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Data sheet | Pressure switch, Differential Pressure switch and Thermostat, RT-E
Technical data
Ordering
Enclosure *) IP66 or IP54 (version with external manual reset)
Ambient temperature - 20 – 65 °C
Cable entry 2 x Pg 13.5 Cable diameter: 6 – 14 mm
Contact material Gold plated AgCdO
Contact load Must be used with a certified Ex ia barrier satisf ying the input parameters
Contact system Single-pole changeovers switch (SPDT)
*) IP degree can only be obtained on enclosure without fractures / damages. RT-E must be protected against unintended impacts.
Pressure switches for R717 1), HCFC, HFC and HC refrigerants
Typ e
Regulating
range
Differential
Δp
[bar] [bar] [bar]
Max.
working
pressure PS
[bar]
Reset
+ welded
ø6.5/10 mm
G 3/8 A
nipple
Code no.
Connection
G 3/8 A
RT 112E 0.1 – 1.1 0.07 – 0.16 7 Auto — 017-518566
RT 113E 0.0 – 0.3 0.01 – 0.05 0.4 Auto — 017-51956 6
RT 121E -1.0 - 0.0 0.09 - 0.40 7 Auto — 017-6184 66
RT 1AE -0.8 – 5.0 0.5 – 1.6 22 Auto 017-500966 —
RT 116E 1 – 10 0.3 – 1.3 22 Auto — 017-520166
RT 5E 4 – 17 1.2 – 4 22 Auto — 017-525266
RT 6AEW 3) 5 – 25 3 34 2) Auto 017-51386 6 —
RT 6AEB 3) 10 – 28 1.5 34 2) Man. (Max.) 017-513466 —
RT 6AES 3) 10 – 28 1.5 34 2) Man. (Max.) 017-50 2166 —
RT 117E 10 – 30 1 – 4 42 Auto — 017-529 866
1
Only types with letter A are suitable for R717
2
Max. working pressure acc. to PED is limited to 28 bar
3
) W=Wächter (pressure control)
B = Begrenzer (pressure control with external reset)
S = Sicherheitsdruckbegrenzer (pressure control with internal reset)
Differential pressure switches for R717, HCFC, HFC and HC refrigerants
Typ e
Regulating
range
Differential
Δp
Operating
range for
LP bellows
Max.
working
pressure PS
Pressure
connection
Code no.
[bar] [bar] [bar] [bar]
3
G
/
A
RT 260AE 0.5 – 4 0.3 -1 – 18 22
RT 262AE 0.1 – 1.5 0.1 -1 – 9 11 017D 003 066
8
+ welded nipple
ø6 .5/10 mm
017D003666
Thermostats
Typ e
Regulating
range
[°C] [°C]
Differential Δp
at lowest
range setting
[°C] [°C]
at highest
range setting
Max.
sensor
temperatur
Type of
charge
Capillary
tube
length
[m]
Code no.
RT 9E -45 – -15 2.2 – 10 1 – 4.5 150 State Vapour 5 017- 61786 6
RT 14E -5 – 30 2 – 8 2 – 10 150 Adsorption 2 017-509 866
RT 14E -5 – 30 2 – 8 2 – 10 150 Adsorption 5 017-6179 66
RT 101E 25 – 90 2.4 – 10 3.5 – 20 300 Adsorption 2 017-512666
RT 101E 25 – 90 2.4 – 10 3.5 – 20 300 Adsorption 5 017-618066
RT 107E 70 – 150 6 – 25 1.8 – 8 215 Partial 2 017-51536 6
RT 107E 70 – 150 6 – 25 1.8 – 8 215 Partial 5 017-618266
RT 123E 150 – 250 6.5 – 30 1.8 – 9 300 Partial 2 017-521666
RT 123E 150 – 250 6.5 – 30 1.8 – 9 300 Partial 5 017-618366
Sensor pockets of RT-E thermostats
RT 14E, RT 107E, RT 123E, RT 101E Brass: 017-437066 18/8 stainless steel: 017-436966
© Danfoss | DCS (az) | 2018.03
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Data sheet | Pressure switch, Differential Pressure switch and Thermostat, RT-E
Safety requirements
Electrical connection
RT-E pressure, differential pressure switches
and thermostats comply with the requirements
for explosive atmosphere 2014/34/EU
acc. to ATEX, zone 1.
Only apparatus designed, constructed and
released by Danfoss must be used for application
concerned. Danfoss can accept no responsibility
in case of alterations made on the switches or
the use of them against the Danfoss instructions.
Original Danfoss spare parts approved for use in
explosive atmosphere can only be used.
The RT-E pressure switch placed in explosive
zone must always be wired through reliable
zener barrier, placed outside ex-zone, to ensure
insufficient energy supply to cause the ignition
of surrounding atmosphere by an electrical spark
or the heating of components of circuitry.
The equipment to be used for electrical load
limiting must always be approved for use
in the zone concerned.
The application covers systems that must be
located within the EU or EFTA and comply with
the existing EU legislation, such as Pressure
Equipment Directive (PED) 2014/68/EU,
the directive concerning potential explosive
atmosphere (ATEX) 2014/34/EU and other related
EU standards. The system where RT-E is mounted
must always comply with local directives,
legislation or any other regulation applying in
the area of installation. The Danfoss products
comply with the requirements of ATEX directive,
but Danfoss takes no responsibility for the
classification of explosive zone.
Cables and cable entries approved for the
application must be used and can not be in
contact with sharp edges. Cables must be
connected with adequate stress relief that way
that pulling forces can not be carried throug
the cable to the terminal.
Wire dimension: min. 0,75mm
²
Note:
A particular system can be classified in different
zones, for different parts of the system.
Intrinsic safety
protection method
Installation
and maintenance
EX - zone Non EX - zone
Only authorised persons, who are certified in
installing and maintaining the systems may do
the installation, maintenance and change of the
switch.
In the event of strong pulsation in the system,
bellows must be protected against fatigue failure
by use of damping coil.
Electrical data for intrinsically
safe specification
(for all RT-E types):
Ui: 29 V
Signal
Ii: 0.5 A
Pi: 1 W
Ci: 0.5 nF
Zener barrier
Li: 0.2 µH
The cycle frequency of the RT-E switch must be
kept as low as possible. The vibration level must
be kept as low as possible.
Any overload of the RT-E switch must be
prevented. Overloaded or damaged apparatus
must be exchanged.
© Danfoss | DCS (az) | 2018.03
DKRCC.PD.CB0.C5.02 | 520H12283 | 3
Data sheet | Pressure switch, Differential Pressure switch and Thermostat, RT-E
Design and function
Pressure switch, type RT
Differential pressure switch, type RT
Pressure switches
RT-E switches are similar to non-explosive
version of RT. Main design changes include
stainless steel frame and metalised front cover to
keep surface resistance below 1 Gohm.
By turning setting knob (5) the main spring (12)
can be set to balance the pressure in the bellows.
A rise in pressure compresses the bellows and
moves the main spindle (15) upwards until spring
and bellows pressure are in equilibrium.
The main spindle (15) is fitted with the guide
bush (17) and differential pressure setting nut
that together transfer the main spindle
movement to the switch (16).
RTE6AEW/B/S has double fail-safe bellows: outer
and regulating (inner bellows).
Differential pressure switches
An RT-E differential pressure switch contains
single-pole changeover switch that makes or
breaks depending on pressure differential
between two counteracting bellows elements
(LP and HP). The bellows (4) and (24) are
respectively connected to lower pressure port
and higher pressure port. The main spring (12)
can be set for different differential pressure by
the setting disc (5). If the differential pressure
between higher and lower pressure falls, the
spindle (15) moves downwards and via the upper
guide bush (17) actuates the switch contact arm
(18). The reverse action occurs if the differential
pressure rises.
© Danfoss | DCS (az) | 2018.03
Thermostat, type RT
Thermostats
The thermostatic element consists of sensor (29),
capillary tube (28) and bellows element (23).
Charge in the element reacts to temperature
variations and increases the pressure in the
bellows when temperature rises. By turning the
setting knob (5) the main spring (12) can be set
to balance the pressure in the element. A rise in
temperature of the sensor compresses the
bellows and moves the main spindle (15)
upwards until spring force and element pressure
are in equilibrium. Such movement is transferred
to the switch (16) and causes its on or off action.
DKRCC.PD.CB0.C5.02 | 520H12283 | 4
Settings The range is set by using setting knob (5).
5
Tools must be used to set switches fitted with
seal cap. To read the range scale front cover must
be removed. On the units with adjustable
differential, differential disc (19) must be set after
removing front cover. For proper adjustment
differential roller must be used. Detailed
information can be found in RT data sheets,
non-explosive version.
19
Dimensions [mm] and
weights [kg]
RT-E housing (pressure switches and thermostats)
Net weight approx. 1 kg
RT-E (pressure and differential pressure switches)
© Danfoss | DCS (az) | 2018.03
RT 1AE RT 6AE RT 260AE RT 262AE
DKRCC.PD.CB0.C5.02 | 520H12283 | 5
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