Danfoss KPU 6B, KPU 6W, KPU 5, KPU1B, KPU1 Installation guide

Installation guide

Pressure switch

KPU

Application

KPU pressure switches are for use on commercial
refrigeration and air conditioning systems to give protection

060R9767

against excessively low suction pressure or excessively
high discharge pressure.

They are also used for starting and stopping refrigeration

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

compressors and fans on air-cooled condensers.
KPU pressure switches are fitted 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 Specification

Code number

Application Typ e

KPU 1 060-52 31 060- 5233 Auto. SPDT — 6 in. – 108 10 – 60 250 290

Low Pressure
Switch Cut O ut
on pressure
fall

Fan switch KPU 5 060 -5241 060-5242 Auto. SPST(NO) close High open Low 100 – 465 25 – 85 510 530

High Pressure
Switch
Cut Out on
pressure rise

* 610psig - MWP for products used according to 2014/68/EU PED directive.

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

KPU 2 060-5237 060 -5235 Auto. SPST(NO) close High open Low 6 in. – 73 6 – 30 250 290

KPU 2 060-5239 060 -5240 Auto. SPDT — 6 in. – 73 6 – 30 250 290

KPU1B 060 -5232 060-52 34 Man (Min.) SPDT — 28 in. – 100 10 fixed 250 290

KPU 6W

KPU
6B

¼ in

male flare

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

060 -5244 060-5246 Man. (Max.) SPDT — 100 – 600 60 fixed 675 / 610* 725

36 in. cap.
tube w. ¼

in flare nut

Reset

Contact system

Typ e

Switch
action

Regulating

range

[inHg] [psig]

Differential

∆p

[psi]

Max.
working
pressure

[psig]

Max.

testing

pressure

[psig]

060R9767

Ambient

temp.

[°F]

-40 – 122

(175 for

max.

2 hours)

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.

© Danfoss | DCS (sb) | 2019.12

AN212086434305en-000101 | 520H11543 | 1

Mount the KPU pressure switch on a bracket
or on a completely flat 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
effectively damped e.g. by connection the pressure
switches to the refrigeration system through a capillary
tube.

Recommendations for capillary tube and flare 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 flare 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 flare nuts as it may damage the threads

9. Protect the capillary tube from damage caused by vibrations

–

– when the switch is mounted remote from the compressor,

– when the switch is mounted remote from the compressor

Screws for
bracket mounting

Mounting holes
for flat surfaces

causing leaks.

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.

make the pressure connections away 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.

Wiring

Electrical ratings according to UL regulations

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

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

2 | 520H11543 | AN212086434305en-000101

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 fingers 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.

© Danfoss | DCS (sb) | 2019.12