Danfoss KPU Series Installation Manual

Installation guide

Pressure switch

KPU

060R9767

060R9767

© Danfoss | DCS (jmn) | 2016.11

DKRCC.PI.CD0.F4.22 | 520H11543 | 1

Application

KPU pressure switches are for use on commercial
refrigeration and air conditioning systems to give protection
against excessively low suction pressure or excessively
high discharge pressure.

They are also used for starting and stopping refrigeration
compressors and fans on air-cooled condensers.
KPU pressure switches are tted with the Single-Pole Single­Throw (SPST) or Single-Pole Double-Throw (SPDT) switches,
suitable for direct as well as indirect (with a contactor) control.

KPU pressure switches are available in several pressure ranges
and are compatible with refrigerants listed below. KPU 6W and
KPU 6B are fail safe switches for high pressure refrigerants.
Standard enclosure is ~NEMA 1.

Product Specication

Application Typ e

Code number

Reset

Contact system

Regulating

range

[inHg] [psi g]

Dierential

∆p

[psi]

Max.
working
pressure

[psig]

Max.

testing

pressure

[psig]

Ambient

temp.

[°F]

¼ in

male are

36 in. cap.
tube w. ¼

in are nu t

Typ e

Switch
action

Low Pressure
Switch Cut O ut
on pressure
fall

KPU 1 06 0-5231 060 -5233 Auto. SPDT — 6 in. – 108 10 – 60 250 290

-40 – 122

(175 for

max.

2 hours)

KPU 1 060- 5236 — Auto. SPST(NO) close High op en Low 6 in. – 108 10 – 60 250 290

KPU 2 060 -5237 060-52 35 Auto. SPST(NO) close High open Low 6 in. – 73 6 – 30 250 290

KPU 2 060- 5239 060-524 0 Auto. SPDT — 6 in. – 73 6 – 30 250 290

KPU1B 060 -5232 060-523 4 Man (Min.) SPDT — 28 in. – 100 10 x ed 250 290

Fan switch K PU 5 06 0-5241 060 -5242 Auto. SPST(N O) close High op en Low 100 – 465 25 – 85 510 530

High Pressure
Switch
Cut Out on
pressure rise

KPU 6W

060 -5243 06 0-5245 Auto. SPDT — 100 – 600 58 – 145 675 / 610* 725

KPU
6B

060 -5244 06 0-5246 Man. (Max.) SPDT — 100 – 60 0 60 xed 675 / 610* 725

* 610psig - MWP for produc ts used according to 97/23/EG PED directive.

Refrigerants:

R22, R134a, R404A, R407A, R407C, R407F, R410A*), R422B,
R422D, R438A, R448A, R449A, R450A, R452A, R507A, R513A

For complete list of approved refrigerants, go to
http://products.danfoss.com/all-products/

*) R410A only for KPU 6W and KPU 6B

Installation

Select an accessible location, where the switch and pressure connection line will not be subject to damage.

IMPORTANT:

Mount the pressure switch in a position that
will allow drainage of liquids away from switch
bellows. Pressure connection of the switch
must always be located on the top side of the
refrigerant line.
This reduces the possibility of oil, liquids, or
sediment collecting in the bellows, which could
cause the switch malfunction.

IMPORTANT:

Ensure the ambient temperature for the pressure
switch is higher than the refrigeration line as that
will prevent liquid migration and accumulation in
the bellows.

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Recommendations for capillary tube and are connections:

1. Ensure self-draining of the capillary tube to minimize

clogging.

2. Coil excess capillary tube into smooth, circular coils (approx.
3 inch diameter). The coiled tube should be securely fastened
in order to prevent possible damage due to vibration.

3. Leave a little slack in the capillary tube as it helps to damp
mechanical vibrations.

4. Avoid sharp bends as well as re-bending of the capillary tube
on the same point as it weakens the material, increasing the
risk of crack.

5. Never allow for contact between the capillary tube and sharp
or abrasive objects as during vibrations the tube could be
damaged due to friction.

6. Purge the piping before connecting pressure switches.

7. Always use two wrenches

tightening the are nut on
the pressure switch. One
wrench should support the
connector while the second
wrench isused to tighten the
nut.

8. Do not over tighten are nuts as it may damage the threads
causing leaks.

9. Protect the capillary tube from damage caused by vibrations
from compressor:

–

when the switch unit is mounted directly on the compressor,
the capillary must be secured to the compressor so that
everything vibrates as a whole.

– when the switch is mounted remote from the compressor,

make the pressure connections away from thecompressor.

– when the switch is mounted remote from the compressor

and the pressure connections have to be on the compressor,
then damping coils must be used between the compressor
and the pressure switch.

NOTE:

After installing the pressure switch, evacuate theplant in
accordance with applicable EPA and other regulations,
to remove air, moisture, and other contaminants.

Screws for
bracket mounting

Mounting holes
for at surfaces

120 V AC 24 FLA, 144 LRA – make only

240 V AC 24 FLA, 144 LRA – make only

240 V DC 12 W pilot duty

Wiring

Electrical ratings according to UL regulations

European electrical ratings according to EN 60947

AC1 AC3 AC15 LR DC13

16 A 16 A 10 A 112 A 12 W

400 V 220 V

CAUTION:

Disconnect power supply before wiring connections
are made or service to avoid possible electrical shock or
damage to equipment.
Do never touch live parts with your ngers or with
anytool.

NOTE:

All wiring should conform to the National Electrical Code
and local regulations.
Use copper wire only.
Use terminal screws furnished in the contact block.
Do not exceed tightening torque 20 lb. in (2.3 Nm).
Do not exceed electrical ratings for the switch.

The terminal block as well as grounding screw
are accessible after dismounting of the front cover.

Mount the KPU pressure switch on a bracket
or on a completely at surface.
Mounting to an uneven surface might cause improper switch
operation.
For bracket mounting use only the 10-32x3/16 screws provided
with the switch. If other screws are used function of the
pressure switch might be disturbed (they may not protrude
into the switch more than 1/8 in.).

Use only the mounting holes provided; no other holes are to
be added to the switch.

IMPORTANT:

Pressure pulsations in the refrigeration system
reduce life time of the bellows and might disturb
switch function. Pressure pulsations should always be
eectively damped e.g. by connection the pressure
switches to the refrigeration system through a capillary
tube.

Load ~Line

B

C

A

D

C

D

A

B

© Danfoss | DCS (jmn) | 2016.11

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Contact function test (Manual trip)

When the electrical leads are connected the contact function
can be manually tested regardless of pressure condition in
the system. The manual trip lever is located in the left side
of the KPU. It must be operated with ngers only. Do not use
screwdriver as it will damage the switch.

NOTE:

While operating the manual trip on KPU
switches with manual reset it is necessary
to push the reset knob.

NOTE:

Adjust the pressure switch with settings specied by the
manufacturer of the controlled quipment.
Do not exceed the pressure ratings of the controlled
equipment or any of its components when checking
pressure switch operation or operating the controlled
equipment.
Do not adjust pointers beyond the highest or lowest
indicator marks on the scale plate, as this may cause
inaccurate switch operation.

A: Manual trip. Press the lever up. USE FINGERS ONLY!
B: Manual reset button

(available only for contols with manual reset function)

C: Terminal block
D: Grounding screw

A: Dierential adjusting screw
B: Locking plate
C: Range adjusting screw
D: Cover screw

Adjustment

Before adjustment, loosen the locking plate.
For setting use the Universal Refrigeration Wrench.

Wire dimensions: 10 AWG max.
Cable entry: 7/8 in. cable entry for ½ in. male pipe thread
connection (conduit boss) or similar (Pg13.5 or Pg16) screwed
cable entry.

Wiring Option A:

– Low Pressure Switch Cut Out on pressure fall
– Condenser Fan Cycling

Wiring Option B:

– High Pressure Switch Cut Out on pressure rise

Load ~Line

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2

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Adjustment:
Low Pressure Switch

Cut out on pressure fall
with automatic reset.

Scale plate directly indicates
the Cut In and the Dierential
set points.

1. Set Cut In by adjusting range screw.
Turn the screw clockwise to lower the set point.

2. Then set Dierential by adjusting dierential screw. Turn the
screw clockwise to increase the Dierential.

3. The Cut Out setting equals the Cut In
less the Dierential: CUT OUT = CUT IN - DIFFERENTIAL

Adjustment:
Condenser Fan Cycling

Scale plate directly indicates
the Cut In and the Dierential
set points.

1. Set Cut In by adjusting range screw.
Turn the screw clockwise to lower the set point.

2. Then set Dierential by adjusting dierential screw. Turn the
screw clockwise to increase the Dierential.

3.The Cut Out setting equals the Cut In less
the Dierential: CUT OUT = CUT IN - DIFFERENTIAL

Adjustment:
Low Pressure Switch

Cut out on pressure fall
with manual reset.

Scale plate directly indicates the Cut
Out set point. There is no pointer for
the Dierential.
The Dierential pressure value is
xed and printed on the scale plate.

Adjustment:
High Pressure Switch

Cut Out on pressure
rise with automatic reset.

Scale plate directly indicates
the Cut Out and the Dierential
set points.

1. Set Cut Out by adjusting range screw.
Turn the screw clockwise to lower the set point.

2. Then set Dierential by adjusting dierential screw. Turn the
screw clockwise to decrease the Dierential.

3. The Cut In setting equals the Cut Out
less the Dierential: CUT IN = CUT OUT - DIFFERENTIAL

Adjustment:
High Pressure Switch

Cut Out on pressure
rise with manual reset.

Scale plate directly indicates
the Cut Out set point.
There is no pointer for the
Dierential.
The Dierential pressure value is
xed and printed on the scale plate.

1. Set Cut Out by adjusting range screw.
Turn the screw clockwise to lower the set point.

2. The Cut In setting equals the Cut Out
less the Dierential: CUT IN = CUT OUT - 60 psi

1. Set Cut Out by adjusting range screw.
Turn the screw clockwise to lower the set point.

2. The Cut In setting equals the Cut Out plus
the Dierential: CUT IN = CUT OUT + 10 psi

NOTE:

Cut Out set point must be above absolute vacuum!
If the Dierential is set too high then the switch
will not stop the compressor.

IMPORTANT:

The scale plate is only for reference and for more
precise setting a pressure gauge should be used.

IMPORTANT:

After installing and adjusting pressure switch run the
controlled equipment several times (at least three
cycles) at normal operating conditions.

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