Danfoss CS Data sheet

Data Sheet

Pressure switch
Type CS

For air compressors and water boosters

CS pressure switches have a built-in pressure
operated, three-pole switch. The contact
position of which depends on the pressure in
the connector and the range setting and
adjustable dierential.

The pressure switches are tted with a manual
switch that will lock the contact system in the
open position independently of the pressure in
the system. Pressure switches with relief valve is
used in compressed air systems where pressure
relief on the compressor piston before start is
required.

The CS is suited for automatic start and stop of
air compressors and water boosters.

Features:

• Pressure ranges 2 – 20 bar

• Pressure connection G ½ or G ¼

• Contact system 3-pole (TPST) as standard
available also as an accessory

• Adjustable dierential

• Relief valve as accessory

• Manual switch to lock the contact system

• Enclosure IP43 or IP55

• Special versions with pressure connection
made of polyacetal suitable in drinking water
applications

AI239086444789en-000701

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Danfoss

31E58

Slide ring

Earth screw

Cover screw

Cover

Spindle

Toggle arm

Snap spring

Snap arm

Switch housing assy

Self-tapping screw

Manual switch

Base

Grubscrew

Stop pressure screw

Pressure pad

Spring retainer

Compression spring

Pressure shoe

Diaphragm

Flange, G ¼ or G ½

Cap

Dierential arm

Tension spring

Dierential pressure screw

Bracket

Pressure switch, Type CS

Function

Figure 1: Design and function

The pressure switch is built up of the following main elements: connector, diaphragm, snap system, main spring,
dierential spring and a 3-pole or one-pole contact system. The stop pressure must be set on the main spring and
the dierence between start and stop pressures on the dierential spring.

Pressure from the controlled system is led, via the connector, to the diaphragm. The diaphragm converts this
pressure to a mechanical movement which is transferred by the snap system to the contact system. In this way, the
contact system starts or stops a compressor/pump.

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A

Example 1

Control of an air compressor with a CS pressure
switch.

Example 2

Control of a compressor with a CS pressure switch
tted with pressure relief valve. Note the check valve
between pressure relief line and reservoir.

Example 3

Control of an air compressor with a CS. An EV210B 3B
solenoid valve is recommended where there is need
for especially fast pressure relief.

CS

Danfoss

31E22

CS

A

Danfoss

31E27

CS

A

Example 4

Control of a centrifugal pump with a CS, via an
automatic star-delta switch, motor starter, or similar.

Example 5

Pressure boosting system for domestic circuits. A type
CS switch is used to start/stop the pump.

CS

A

Danfoss

31E56

Motor starter or automatic start-delta switch

Pressure switch, Type CS

Application

Table 1: Application examples

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Electrical life on rated load

100.000 operations

Mechanical life

1.000.000 operations

Ambient temperature

-20 – 70 °C

Temperature of medium

(1)

Water

0 – 70 °C

Air

-20 – 70 °C

Vibration-proof

0 – 1000 Hz at 4g

Resonance frequency,
see Figure 2

Direction A-B

341 Hz

Direction C-D

332 Hz

Direction E-F

488 Hz

Diaphragm material

Hytrel

Pressure connector

Special

Polyacetal, G ½

Others

Silumin, G ¼ or G ½

Pressure relief valve (capacity)

2000 cm3 from 10 – 1 bar in 18.8 sec.

Grade of enclosure to IEC 529

IP43 or IP55

Danfoss

U31E34

Contact load

IeU

e

AC-3

12 A

220 – 415 V

AC-3

9 A

600 V

DC-13/14

2 A

220 V (3 contacts in series)

Wire dimension

solid / stranded

0.7 – 2.5 mm

2

exible,

with / without ferrules

0.75 – 2.5 mm

2

exible,

with ferrules

0.5 – 1.5 mm

2

Tightening torque

max. 1.2 Nm

Rated impulse voltage

4 kV

Pollution degree

3

Short circuit protection, fuse

25 A

Insulation

600 V

IP-index

IP43 or IP55

Pressure switch, Type CS

Product specication

Technical data

Table 2: Specications

(1)

(1)

For water and seawater, max. 80 °C

For water and seawater, max. 80 °C

Figure 2: Resonance frequency

Table 3: Contact load

Table 4: Properties according to EN 60947

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Danfoss

31E43

12Stop pressure screw

Dierential screw

Danfoss

31E47

Turns of
screw

Pressure switch, Type CS

Setting

Figure 3: Adjustment

All standard versions of CS pressure switches are preset and supplied with springs under minimum compression.

1.

Turn the stop pressure screw (1) the given number of times towards + (high stop pressure), see Figure 4: Stop

pressure graph.

2.

Turn the dierential screw (2) the given number of times towards + (max. dierential), see Dierential pressure

nomograms.

3.

Start the plant and let it run until the required stop pressure is reached.

4.

Turn the stop pressure screw (1) towards minus (lower stop pressure) until the plant stops.

5.

Reduce the pressure to the required start pressure.

6.

Turn the dierential screw (2) towards minus (smaller dierential) until the plant starts.

7.

Check that the plant stops and starts at the required pressures.

 NOTE:

If the dierential is set at a value greater than the stop pressure the plant cannot start. If this is the case, set the
dierential at a smaller value (towards minus).

Figure 4: Stop pressure graph

Example:

A compressor is to be regulated by a CS pressure switch. The start pressure is 3.5 bar, and the stop pressure 5 bar.
The choice should be a CS with a range of 2 – 6 bar.

1.

Turn the stop pressure screw (1) about 12 times. See Figure 3: Adjustment.

2.

Turn the dierential screw (2) about 4.5 times. See Figure 8: CS 2–6 [bar]. Take a straight line from 5 bar stop
pressure on the nomogram to the dierential, 1.5 bar and read o the number of turns, i.e. 4.5.

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Danfoss

31E52

Danfoss

31E51

d > 8.5 mm – 1
d ≤ 8.5 mm – 2
031E0293

Danfoss

31E73

Pressure switch, Type CS

Take a straight line from 5 bar stop pressure on the nomogram to the dierential, 1.5 bar and read o the number of
turns, i.e. 4.5.

Installation

Recommended orientation

The pressure switches will operate regardless of their orientation. However, to meet the enclosure requirements of
IP43 and IP55, they must be mounted vertically with the connection downwards. The CS pressure switches are self­supporting (on the connection).

Fitting a pressure relief valve:

1.

Remove the blanking plug

2.

Fit the pressure relief valve

3.

Fit the plastoform screw

Figure 5: Installation

Figure 6: Installation

Fitting screwed cable entries

The accessory bag contains two sets of metal gaskets each with dierent internal diameters. These will give a
sucient cord relief if used correctly with the cable diameter concerned.

Drain hole

If because of large temperature variations there is a risk of condensate forming in the pressure switch, a screwdriver
can be used to make a drain hole in the enclosure.

Figure 7: Drain hole

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Danfoss

31E53

Stop pressure

No. of turns
on Δp screw

CS 2–6 [bar]

Differential

Danfoss

31E54

Stop pressure

CS 4–12 [bar]

Differential

No. of turns
on Δp screw

Danfoss

31E55

Stop pressure

CS 7–20 [bar]

Differential

No. of turns
on Δp screw

Danfoss

31E61

Danfoss

31E62

Danfoss

31E63

Danfoss

31E49

IeU

e

AC-3

12 A

220 V – 415 V

9 A

600 V

DC-13 / 14

2 A

220 V (3 contacts in series)

Pressure switch, Type CS

Dierential pressure nomograms

Figure 8: CS 2–6 [bar]

Figure 9: CS 4–12 [bar]

Dimensions [mm] and weights [kg]

Figure 11: Dimensions [mm]

Figure 10: CS 7–20 [bar]

Weight approx. 0.5 kg

Mains connection

Figure 12: 3-pole AC load

Table 5: Contact load

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Figure 13: 1-pole AC load

Figure 14: 1-pole DC load

Stop pressure p

e

[bar]

Min. dierential

Δp [bar]

Max. dierential

Δp [bar]

Max. test

pressure p

e

[bar]

Grade of

enclosure

Pressure

connection

Code no.

Type

2 – 6 

0.72 – 1.0

1.0 – 2.010IP43

G ¼

031E020266

1-pole

2 – 6  

0.72 – 1.0

1.0 – 2.010IP43

G ¼

031E020066

3-pole

2 – 6  

0.72 – 1.0

1.0 – 2.010IP55

G ¼

031E020566

3-pole

2 – 6  

0.72 – 1.0

1.0 – 2.010IP43

G ½

031E021066

3-pole

2 – 6 

0.72 – 1.0

1.0 – 2.010IP55

G ½

031E021566

(1)

3-pole

4 – 12

1 – 1.5

2.0 – 4.020IP43

G ¼

031E022066

3-pole

4 – 12

1 – 1.5

2.0 – 4.020IP55

G ¼

031E022566

(1)

3-pole

4 – 12

1 – 1.5

2.0 – 4.020IP43

G ½

031E023066

3-pole

4 – 12

1 – 1.5

2.0 – 4.020IP55

G ½

031E023566

(1)

3-pole

7 – 20

2 – 3.5

3.5 – 7.032IP43

G ¼

031E024066

3-pole

7 – 20

2 – 3.5

3.5 – 7.032IP55

G ¼

031E024566

3-pole

7 – 20

2 – 3.5

3.5 – 7.032IP43

G ½

031E025066

3-pole

7 – 20

2 – 3.5

3.5 – 7.032IP55

G ½

031E025566

(1)

3–pole

Stop pressure p

e

[bar]

Min. dierential

Δp [bar]

Max. dierential

Δp [bar]

Max. test

pressure p

e

[bar]

Grade of

enclosure

Pressure

connection

Code no.

Type

2 – 6 

0.72 – 1.0

1.0 – 2.010IP43

G ½

031E101066

3-pole

4 – 12

1 – 1.5

2.0 – 4.020IP43

G ½

031E101266

3-pole

7 – 20

2 – 3.5

3.5 – 7.032IP43

G ½

031E101466

3–pole

Description

Code no.

Three pole contact system (TPST)

031E029166

Pressure relief valve, incl.

xing screw (for 6 mm pipe/hose)

031E029866

Pressure relief valve, incl.

xing screw (for 1/4 in. pipe/hose)

031E029766

Two Pg 16 screwed cable entries with gaskets (cable diam. 6.5 – 15 mm)

031E029366

Nipple with 7/16-20 UNF and M10 x 1 int.

031E029666

File name

Document type

Document topic

Approval authority

BK_W_0862_01_2108

Food and Health - Performance

Certicate

-

PZH

RU C-DK.БЛ08.В.00063_18

Electrical - Safety

Certicate

EMC/LVE

EAC

UA.1O146.D.00075-19

UA Declaration

EMCD/LVD

LLC CDC EURO TYSK

060-9650.AC

EU Declaration

LVD/RoHS

Danfoss

Pressure switch, Type CS

Ordering

Table 6: Standard pressure switch type CS

(1)

(1)

Preferred versions

Preferred versions

Table 7: Special versions with Polyacetal pressure connection - suitable for drinking water

Accessories and spare parts

Table 8: Accessories and spare parts

Certicates, declarations, and approvals

The list contains all certicates, declarations, and approvals for this product type. Individual code number may have
some or all of these approvals, and certain local approvals may not appear on the list.

Some approvals may change over time. You can check the most current status at danfoss.com or contact your local
Danfoss representative if you have any questions.

Table 9: Certicates, declarations, and approvals

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