Orion KU Installation And Operating Instructions Manual

Website : www.orion-instruments.com

Kaustubha Udyog (Orion Instruments)

S. No. 36/1/1, Sinhgad Road, Vadgaon Khurd, Pune 411 041 INDIA
Tel.: [phone]
Telefax : [phone] / 25460486

Email : [e-mail] / [e-mail]

Certificate No.: FM72815

BULLETIN NO. : KA170306

INSTALLATION AND OPERATING INSTRUCTIONS

KU Pressure Switches

Construction:

KU series pressure switches are housed in pressed steel powder coated enclosure and are recommended for panel mounting or indoor
service. The repeat accuracy is better than +/-1.5 % FSR. Pressure port is 1/4” BSPM standard.

Principle of Operation:

The pressure in the pressure capsule is converted into force by means of a reinforced rubber diaphragm and a calibrated piston, which is
balanced by a compression spring from above. When the force generated by the pressure in the pressure capsule exceeds/falls beyond
the balancing spring force, an electrical element is actuated through a bell crank lever mechanism for accurate switching.

Please use the pressure switch well within the pressure and also the electrical parameters

Mounting

The pressure switches can be mounted in any direction.
a) Pressure switches can be mounted directly in case the mounting is rigid.
b) For panel mounting, Please use M4 bolts of appropriate length through the mounting holes . If the equipment is subject to vibration,

please use rubber washers / pads between the panel and the switch.

Connect the pressure tubing to the pressure port. The pressure port size is generally 1/4" B.S.P. Male, unless specially ordered
otherwise. Other sizes can be obtained via adaptors.

Electrical Connections

Please use electrical loads well
within the limits specified for the
microswitch.

Wiring:

Please refer figure 2.
a) Remove the cover.
b) Pass the cable through the cable

bush (usually provided with the
switch) and connect the wiring as
per the wiring diagram.

The wiring code is as per the details
given below.

Terminal 1 : (C) Common
Terminal 2 : (NC) Normally Closed
Terminal 3 : (NO) Normally Open

Please disconnect supply before wiring the switch, or removing the wiring. The cover should not be removed, if the supply is on.

APPROX. DIMENSIONS IN

mm

inches

INSTALLATION DRAWING

Fig 1.1

(0.90)

23

Pressure Port

(3.26)

83

(0.35)

9

17.5

(0.68)

33.5

(1.31)

12

(0.47)

(0.94)

24

1/4" BSP(M)

Cable Entry

12.5

(0.49)

60.5

(2.38)

Ø5, Mtg. Holes, 3 Nos.

(0.19)

Set Screw

Differential Screw

(1.75)

44.5

(0.82)

21

97.5

(3.83)

Fig. 1.2

Z

2 3

1

Set Point Adjustment:

Ensure the supply is off, before setting the switch. Status of
contacts can be checked with a multimeter / continuity tester.

A) For adjustable differential models

Please refer Figure 2

1) Decide the cut-in (lower) pressure P1 & the cut-out
(upper) pressure P2. The differential will be (P2 – P1).

2) Remove the cover.

3) Set the cut-in point on the main-scale with the help of the
set-screw.

4) Turn the differential screw to the extreme positive end.

5) Apply the desired cutout (higher) pressure to the
pressure switch

6) Decrease the differential pressure setting by turning the
differential screw till contacts changeover.

7) Some minor adjustment will be required to achieve the
exact cutin (lower) / cutout (higher) point, which can be
checked with the help of a proper pressure measurement device.

8) Replace the cover back in the position.

Operating Temperatures:

The operating condition temperature restrictions for the KU Switch are as follows:

o o

Ambient : -5 C to +60 C

o o

Operational (all models): -5 C to +80 C
Note : Switches with temperature ranges beyond the ones specified above can be
supplied on request.

o o

storage :-5 C to +60 C

Trouble Shooting Tips:

Generally no problems are observed if the pressure switch selection, wiring and the
setpoint is proper. For a pressure switch selection procedure, please consult our sales
office. For properly selected pressure switches, if following symptoms are observed,
the likely causes and remedies are as stated below.

Symptom 1: Switch does not operate

1) Wiring may not me correct. Check electrical connections to the pressure switch, if
they are as per wiring diagram.

2) Pressure does not reach the pressure port.
a) Check if the entry to the pressure capsule is not blocked by frozen process or

scales or impurities in the process.
i) If this is the case, try freeing the blocked path by a blunt tool in case of

scales or impurities.

ii) For frozen process, it is advisable to use chemical seals.

DO NOT OPEN THE PRESSURE CAPSULE IN ANY EVENT.

If the cause is none of the above mentioned probabilities, proceed as per the
following steps.

b) Check the system pressure & set point of pressure switch. For use of

pressure switch for falling setpoints, system pressure has to be greater than
cutin point. For use of pressure switch for rising setpoints, the system
pressure may not be reaching / exceeding the cutout point.
i) For adjustable differential models turn the differential screw to the extreme

negative end.

ii) Use 'T' connection & connect calibrated pressure gauge to the 'T'

connection as shown in the figure 4.

iii) Adjust the setpoint such that the system pressure is greater than the cut-

out point of the pressure switch.

iv) If the switch still does not operate, remove the pressure switch physically

from the system. There should be continuity between terminals 1 & 2. If no
continuity is observed, the pressure switch should be returned to the
factory.

Symptom 2: Short Wiring

Isolate the switch electrically. Check the continuity between terminals and the screws fitted to the body. If no continuity is observed in
between any of the terminals and screws fitted to the body, check the short connection elsewhere in the circuit. If continuity is observed,
the wires of the pressure switch have internally touched the body, and the switch should be returned to the factory.

Symptom 3: Leakage

In case leakage is observed, the pressure switch has to be returned to the factory without opening the pressure capsule. Check for the
following likely causes and use a new switch taking proper precautions.
a) System pressure is greater than working pressure : Use an overrange protector or a switch with appropriate maximum working

pressure.

b) Incompatible wetted parts : The working medium may not be compatible with wetted parts, which damages the sealing of the process

from working parts. Use a chemical seal for the pressure switch or use proper compatible wetted parts.

c) Excessive process temperature : Process temperature may exceed maximum allowable temperature, which in turn damages the

diaphragms. Use an impulse tubing of proper length for cooling the process temperature. There may be a pressure drop depending
on length of the impulse tube used. Adjust the setpoint of the pressure switch accordingly.

Symptom 4: Chattering

1) Check the system pressure for surges. Chattering is observed where the system pressure is close to the cutin / cutout point and the
surge pressure exceeds the on-off differential. Use a pressure switch with an adjustable differential or use surge dampers in your
system.

2) If there is a relay in the circuit, check if the relay is properly plugged in. Chattering may be due to loose contacts.

Fig. 2

Front Cover

Main Body

Scale Plate Set Screw

Differential Screw

C - Terminal 1
NC - Terminal 2
NO - Terminal 3

Cable Bush

Fig. 3

Cover

Pressure Port

Fig. 4

'T' Connection

System Pressure

Calibrated

Pressure

Gauge