© Danfoss | DCS (jmn) | 2015.11
DKRCC.PI.CB0.A7.02 | 520H10533 | 2
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. 2. If this gland is not used with a cable, a metal
blinding should be also assembled.
RT units can be fitted in any position. Use the mounting holes (25). With
outdoor installation, the unit should be protected against rainfall. The
bulb should be fixed to the wall by means of a bulb holding bracket
(26). If it is desired to install the bulb in a water or brine tank, this can be
done by using either a capillary stuffing box (31) or a bulb pocket (30).
If bulb pocket is to be used, for correct bulb fitting see fig. 4.
Electrical connection
See fig. 5.
START = make. STOP = break. DIFF. = differential.
Cable diameter: 6 – 14 mm
The earth terminal (38) should be connected to earth.
Wire dimension: min. 0,75mm²
Adjustment
Set the thermostat for minimum actuating temperature (range setting).
Setting is done by rotating the knob (5), at the same time reading the
main scale (9).
The differential is set by rotating the differential adjusting nut (19)
according to the nomogram concerned (fig. 3).
Maximum actuating temperature is the sum of the temperature setting
and the differential.
Example:
An RT 123E is required to regulate the temperature in a drying oven.
Max. temperature 188 °C, min. temperature 180 °C, differential
188 °C - 180 °C =8 °C.
1. Set the thermostat on 180 °C with the knob (5).
2. Set the differential adjusting nut (19) on number 3 which can be
found by reading off the nomogram for the RT 123E in fig. 3.
In general, turning the knob automatically moves both the maximum
and minimum actuating temperatures (break and make) up or down
because of the fixed differential. On the other hand, turning the dif-
ferential adjusting nut only, alters the maximum actuating temperature.
Safety requirements
1.
The refrigeration system must always comply with European Ex
installation standard, EN 60079-14, any local directive and legislation
as well as any other regulation applying in the area of installation.
2.
RT-E temperature control must be used only with reliable means of
limiting the voltage and current to prevent sparks between the
contact surfaces. The equipment to be used for electrical load limit-
ing must be certified for gas group IIC. Also RT-E thermostat must
be installed as a part of IIC electrical installation.
3.
Cable and cable entries approved for the application must be used.
Cables must not be in contact with sharp edges. The cable must be
connected with adequate stress relief in order to prevent that pull-
ing forces can be carried through the cable to the terminal.
4.
The cycle frequency of the RT-E switch must be kept as low as possi-
ble
to prevent fatique failure on the bellows. The vibration level
must be kept as low as possible.
5.
It is recommended to regularly check the function of the RT-E
switch.
6.
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 thermostats or the
use of them against the instructions of Danfoss.
7.
Any overload of the RT switch must be prevented. Overloaded or
damaged apparatus must be exchanged.
8.
Only authorised persons, who are certified in installing and main-
taining refrigration system may do the installation, maintenance
and exchange of the switch. Use only appropriate tools
9.
Dispose of the switch in an environmentally-friendly way.
10.
RTE switches must be installed in area where is low risk of
mechanical damage.
11.
Components within the equipment can exceed the enclosure tem-
perature by 1K (1°C). When the media temperature exceeds 80°C, it
is the responsibility of the user to ensure that the media tempera-
ture does not cause a thermal ignition risk on parts between the
media and the switch enclosure. Maximum media temperature on
temperature switch with 2m capillary tube is 300°C.
12.
Isolation of the intrinsically safe circuit to ground and to the contact
mounting screw has been verified through 500VACrms dielectric
strength testing, carried out in accordance with IEC 60079-11:2011
section 10.3.
13.
Surface of the front cover is sputtered with stainless steel - avoid
abrasion.
14.
Power must be switched off before maintenance and opening the
RT-E.
Product marking
Technical data
Type
Range
[°C]
Max. permissible bulb temperature
[°C]
RT 14E
-5 – 30
150
RT 101E
25 – 90
300
RT 107E
70 – 150
215
RT 123E
150 – 250
300
Permissible ambient temperature
-20 – 65 °C
Intrinsically safe specification
U
i
= 29 V
l
i
= 0.5 A
P
i
= 1 W
C
i
= 0.5 nF
L
i
= 0.2 μH
Contact load
max. 100 mA, 30 V AC / DC
min. 1 mA, 5 V AC / DC
Must be used with a certified Ex ia barrier satisfying the
input parameters.
Temperature
class
Process temperature
limit [°C]
T1
T2
T3
T4
T5
T6
300
289
194
129
94
79
0539 II2G
Ex ia IIC T6...T1 Gb -20 °C ≤ Ta ≤ 65 °C
DEMKO 14 ATEX 1406X
IECEx ULD 14.0013X
U
i
= 29 V I
i
= 0.5 A P
i
= 1 W
C
i
= 0.5 nF L
i
= 0.2 μH
