Danfoss RT Pressure Switch Installation Guide
This guide provides instructions for installing and setting Danfoss RT series pressure switches, including models RT 5, RT 110, RT 112, RT 116, RT 117, RT 121, and RT 200.
Product Data
Pressure Switch Types: RT 5, RT 110, RT 112, RT 117, RT 121, RT 200, RT 116
| Model | Max. Test Pressure |
|---|---|
| RT 110, RT 112, RT 121 | 8 bar |
| RT 5, RT 116, RT 200 | 25 bar |
| RT 117 | 47 bar |
Fitting Instructions
A Pg13.5 cable gland is provided in a separate bag. To ensure the enclosure's IP66 (automatic reset) or IP54 (external reset) rating, assemble the gland as shown in Figure 2. If the cable gland is not used with a cable, a metal blanking plug should be installed.
To dampen strong pressure pulsations, a damping coil (Figure 3 or 4) is often sufficient. If there's a risk of the pressure connection overheating to over 100°C in high-temperature systems, insert a water-filled tube loop (e.g., a 10 mm copper tube) as a temperature lock.
Position the pressure control to avoid exposure to frost in water systems; it can operate on an air cushion.
Setting Instructions
The pressure controller is set by rotating the knob (5) while observing the main scale (9), as shown in Figure 1. The differential is set using the differential adjusting nut (19) according to the nomogram in Figure 6. The maximum operating pressure is the sum of the setting pressure and the differential.
Example Setting
To control the pressure in an oil-fired steam boiler using an RT 116, with a maximum pressure of 9 bar and a minimum pressure of 8.2 bar (differential of 0.8 bar):
- Connect the oil burner to terminals 1-2 of the pressure switch.
- Set the pressure switch to 8.2 bar by rotating knob (5).
- Set the differential adjusting nut (19) to the value indicated by Figure 7, which is determined from the nomogram in Figure 6.
Diagram Descriptions
Figure 1: Internal view of the pressure switch showing the setting knob (5), main scale (9), and differential adjusting nut (19).
Figure 2: Illustration of the correct assembly of the Pg13.5 cable gland for IP66/IP54 protection.
Figure 3: Example of a damping coil (Code no. 060-333366).
Figure 4: Example of a temperature-resistant damping coil with a copper tube (Code no. 060-007166).
Figure 5: Diagram showing temperature considerations for pressure switch installation, indicating maximum and minimum temperatures.
Figure 6: Nomogram used for setting the differential pressure.
Figure 7: Example value from the nomogram for setting the differential.
