Danfoss CS Pressure Switch Installation Guide

Mounting Orientation

The pressure switch connects to the pressure vessel. It operates correctly in any orientation. However, to meet enclosure requirements of IP43 and IP55, it must be mounted vertically with the connection downwards. The connection is self-supporting.

Electrical Connections

Main connection types are illustrated:

• Figure 4: Three-pole load connection.
• Figure 5: Single-pole AC load connection.
• Figure 6: Single-pole DC load connection.

Contact load (Figure 7) involves 3 contacts connected in series.

Setting the Pressure Switch

The pressure switch is set using two screws (Figure 8):

1. Cut-off pressure screw (P)
2. Differential pressure screw (ΔP)

Pressure Setting Guidance

Cut-off Pressure Graphs (Figure 9)

These graphs show the relationship between the number of turns of the Pe screw (labeled A) and the cut-off pressure (Pe) in bar for different pressure ranges. For example:

• CS 2-6 bar: minimum Pe is 2 bar
• CS 4-12 bar: minimum Pe is 4 bar
• CS 7-20 bar: minimum Pe is 7 bar

An example scenario involves controlling a compressor with a 3.5 bar cut-in and 5 bar cut-off pressure, recommending a CS switch with a 2-6 bar range. The procedure involves turning the cut-off pressure screw (1) approximately 12 times, referencing the cut-off pressure graphs. Then, turn the differential screw (2) approximately 4.5 times, using the CS 2-6 nomogram. A straight line drawn from the 5 bar cut-out pressure to the 1.5 bar differential on the nomogram indicates the required 4.5 turns for the differential screw.

Differential Pressure Nomograms (Figure 10)

These nomograms illustrate the number of turns of the ΔP screw (labeled A) needed to set the differential pressure. For example:

• CS 2-6 bar: minimum ΔP is 0.72 bar
• CS 4-12 bar: minimum ΔP is 1 bar
• CS 7-20 bar: minimum ΔP is 2 bar

Important Note: If the differential setting is greater than the cut-off pressure, the system cannot start. Adjust the differential to a smaller value by turning the ΔP screw counterclockwise.

Drain Hole

If significant temperature variations risk condensate formation within the pressure switch, a drain hole can be created in the enclosure using a screwdriver to allow water to escape (Figure 11).

Parts List

The internal components of the pressure switch are detailed in the following list (Figure 12):

1. Slide ring
2. Combi-screw
3. Screw
4. Cover
5. Spindle
6. Toggle arm
7. Snap spring
8. Snap arm
9. Switch housing assembly
10. Self-tapping screw
11. Manual switch
12. Base
13. Grubscrew
14. Screw
15. Pressure pad
16. Spring retainer
17. Compression spring
18. Pressure shoe
19. Diaphragm
20. Flange, G 1/4, G 1/2, 1/4-18 NPT
21. Cap
22. Differential arm
23. Tension spring
24. Tension screw
25. Bracket
26. Pressure gauge connection G 1/4 (Tightening torque: max. 16 Nm)