Danfoss Thermostats with Neutral Zone
Installation Guide for RT 8L, RT 14L, RT 16L, RT 101L, RT 140L
Technical Data
Mechanical Differential (DIFF)
- RT 8L and RT 16L: 1.5K (2.7 °F)
- RT 14L: 1.5K (2.7°F) / 0.7K (1.3 °F) min./max. range
- RT 101L: 2.5K (4.8 °F) / 3.5K (6.7 °F) min./max. range
- RT 140L: 1.8K (3.2 °F) / 2K (3.8 °F) min./max. range
Maximum Ambient Temperature
- RT 8L, RT 14L, RT 101L, RT 140L: -50 °C (-58 °F) – 70 °C (160 °F)
- RT 16L: 50 °C (120 °F)
Maximum Bulb Temperature
- RT 8L: 145 °C (290 °F)
- RT 14L: 150 °C (300 °F)
- RT 16L: 100 °C (210 °F)
- RT 101L: 300 °C (570 °F)
- RT 140L: 240 °C (465 °F)
Min. Temperature Variation Rate
< 1K/15 minutes.
Enclosure
IP 66 acc to IEC 529.
Rating
The marking, e.g. 10 (4) A, 400 V ~ AC means that max. connection current is 10 A ohmic and 4 A inductive at 400 V ~. The max. starting current on motor cutin (L.R.) may be up to seven times the inductive load.
Fitting
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 Figure 10. If this gland is not used with a cable, a metal blinding should be also assembled.
Use the mounting holes item 25.
The thermostat is fitted best with the knob 5 facing upwards.
The thermostat housing and the capillary tube can be placed colder or warmer than the bulb.
In the case of RT 8L and RT14L, the cylindrical bulb can be fixed to a wall by using a bulb holder 26 or it can be fitted in a brine tank by means of a bulb pocket 30 or in capillary tube gland 31. See Figure 1.
If the capillary tube is to be passed through a wall, it can be done most easily by using a grouted-in pipe closed by rubber plugs.
Electrical Connection
Cable connection Pg 13.5. Cable diameter 6 - 14 mm.
The screwed cable entry shown in Figure 11 is used with rigid cable conduit. Earth connection to earth terminal 38.
Setting
The required temperature (= break temperature of contacts 2-3) is set by rotating the knob 5. The setting can be read on the main scale 9.
The required neutral zone (NZ) is found in the diagram. On the lower scale of the diagram, the value at which the neutral zone setting disc 40 is to be set, can be read.
Example: RT 8L
Required temperature: -2.5 °C (27.5 °F). Required neutral zone (NZ): 3 °C (5.5 °F).
The thermostat is set for -2.5 °C (27.5 °F) by rotating the knob 5.
As it can be seen from the diagram, the required dead zone of 3 °C (5.5° F) is obtained by setting the setting disc 40 at 2.4. The make and break temperatures of the switch (see Figure 5) are then – with the differential fixed at 1 °C (1.8 °F):
- Make temperature of contacts 1-4 = -2.5 °C + 1 °C = -1.5 °C (27.5 °F + 1.8 °F = 29.3 °F).
- Break temperature of contacts 1-4 = temperature setting: -2.5 °C (27.5 °F).
- Make temperature of contacts 1-2 = -1.5 °C -3 °C = -4.5 °C (29.3 °F - 5.5 °F = 23.8 °F).
- Break temperature of contacts 1-2 = -4.5 °C + 1 °C = -3.5 °C (23.8 °F + 1.8 °F = 25.6 °F).
Diagrams
Figure 1: Shows various mounting options for the bulb, including wall mounting with holder 26, brine tank mounting with pocket 30, and capillary tube gland 31.
Figure 2: Illustrates the RT 16L thermostat's internal components.
Figure 3: Illustrates the RT 140L thermostat's internal components.
Figure 4: Shows the neutral zone (NZ) settings for RT 8L.
Figure 5: Illustrates make and break temperatures for the switch.
Figures 6-9: Display neutral zone (NZ) and range settings for various RT models (RT 8L, RT 14L, RT 16L, RT 101L, RT 140L).
Figure 10: Depicts the cable gland assembly for IP66/IP54 enclosure rating.
Figure 11: Shows the screwed cable entry for rigid cable conduit.
Figure 12: Indicates the thread size 5/8-18UNF and Pg 13.5 for the cable gland.
