Danfoss KPU 74B, KPU 74, KPU 75, KPU 77, KPU Data sheet

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Data sheet

Thermostat KPU

The KPU Thermostats are temperature controlled electrical switches, which are applied for regulation and safety monitoring of refrigeration and air conditioning systems.

KPU sensors are available with vapor charge or with adsorption charge. The Thermostats with adsorption charge are widely used to give frost protection, while vapor charged sensors are used where small dierential is required.

All KPU Thermostats have a single pole double throw (SPDT) contact system. Theposition of the switch depends on the thermostat setting and the bulb temperature.

Features

Approvals

• Wide temperature regulating range allows use in low, medium, and high temperature refrigeration application and air-conditioningsystems

• Snap-action electrical contacts minimize chatter, bounce and wear, and ensure long-term electrical and mechanical reliability

• Fingertip manual trip feature allows contact function testing without tools

• Easily replaces other manufacturers’ thermostats

• Ultra-short bounce time

UL listed for USA and Canada, le E31024

• Long operating lifetime

• Vibration and shock resistant

• SPDT switch allows NC or NO function option as well as alarm capability

• Automatic and manual reset versions available

Data sheet | Thermostat, KPU

Technical data

Regulating ranges in [°F]

Ambient temperature -40 – 122 °F, 175 °F up to 2 hours

Cable entry

⁄ in cable entry for ½ in male pipe thread connection (conduit boss)

Maximum wire dimension 10 AWG

Enclosure ~NEMA 1

Switch SPDT – single pole double throw

FLA = 24 A at 120 V AC

24 A at 240 V AC

NAM rating

Alternating current

) = 144 A at 120 V AC

LRA

144 A at 240 V AC

Contact load

Direct current 12 W pilot duty at 240 V DC

AC1: 16 A, 400 VA

European rating (acc. to EN 60947)

Alternating current

AC3: 16 A, 400 VA

Direct current DC13: 12 W, 220 V control current

LRA is rated for make only

KPU 61

KPU 62 (room sensor) Vapor charge

KPU 63

KPU 68 (room sensor)

KPU 69

KPU 62

KPU 71

KPU 73 Adsorption charge

KP U 74

KPU 75

KPU 77

-50 0 50 100 150

Data sheet | Thermostat, KPU

Ordering

Typ e

Bulb type

Range

Dierential

at lowest

temperature

setting

at highest

temperature

setting

Max. bulb

temp.

Reset

function

Capillary

tube length

Code no.

[°F] [°F] [°F] [°F] [in]

Vapour 1)

KPU 61 A -20 – 60 10 – 40 2.5 – 13 250 auto. 80 060L5201

KPU 61 B -20 – 60 10 – 40 2.5 – 13 250 auto. 80 060L5203

KPU 61B B -20 – 60 ﬁx e d 11 ﬁxed 3.5 250 man.

) 80 060L5204

) 200 060L5205

KPU 62 C1 -20 – 60 10 – 40 2.5 – 13 250 auto. room sensor 060L5206

KPU 61 B -20 – 60 10 – 40 2.5 – 13 250 auto.

) 80 060L5210

KPU 63 A -60 – 15 18 – 125 5 – 15 250 auto. 80 060L5213

KPU 63 B -60 – 15 18 – 125 5 – 15 250 auto. 80 06 0L5214

KPU 68 C1 25 – 95 8 – 45 3 – 13 250 auto. room sensor 060 L5215

KPU 69 B 25 – 95 8 – 45 3 – 13 250 auto. 80 060 L5217

Adsorption 2)

KPU 62 C2 -20 – 60 9 – 36 3 – 14 175 auto. 4) room sensor 060L5207

Contact system

KPU 73 E3 -15 – 60 6.5 – 32 5 – 50 175 auto. 80 060L5208

KPU 73 E1 -15 – 60 22 – 125 15 – 45 175 auto. 80 060L5209

KPU 73B E3 -15 – 60 ﬁxed 6 ﬁxed 6 175 man.

) 80 060 L52 11

KPU 73 D -15 – 60 6 – 35 5 – 32 175 auto. 80 060L 5212

KPU 71 E2 25 – 70 5.5 – 18 4 – 16 175 auto. 80 06 0L5218

KPU 71B E2 25 – 70 ﬁxed 5 ﬁxed 5 175 man.

) 80 060L 5216

KP U 74 E1 0 – 80 9 – 35 9 – 35 175 auto. 80 06 0L5219

KP U 74 B E1 0 – 80 ﬁxed 10 ﬁ xe d 10 175 man.

) 80 060L5220

KPU 75 F 30 – 95 6 – 29 4.5 – 21.5 230 auto. 80 06 0L 5221

KPU 77 E3 60 – 140 6 – 18 6.3 – 18 265 auto. 80 060L5223

Bulb must be installed in colder position than thermostat

housing and capillary tube.

) Bulb can be placed warmer or colder than thermostat housing and capillary tube, but variations from 70 °F ambienttemperature will inuence the scale accuracy.

) Manual minimum reset. Marked with letter B. Fixed dierential.

These controls have no hand knob.

) With manual switch and top plate.

Switch type – singlepoledoublethrow Switch action Applicaton

1. Terminals 1 – 4 close high and open low Terminals 1 – 2 can be used as

1. Low temperature cut-out

low temperature alarm

2. Terminals 1 – 2 open high and close low Terminals 1 – 4 can be used as

2. High temperature cut-out

high temperature alarm

Data sheet | Thermostat, KPU

Design / Function

1. Temperature setting spindle

2. Dierential setting spindle

3. Main spring

4. Dierential spring

5. Bellows

6. Capillary tube

7. Main arm

8. Switch

9. Cable entry

11. Temperature sensor

12. Setting knob

13. Dierential setting screw

14. Control terminals

15. Ground terminal

16. Contact housing

Key sketch of KPU Thermostat KPU Thermostat without front cover

Switches in KPU Thermostats have a snap-action function, triggered when cut-in or cut-out temperature is reached.

Snap-action creates anumber of advantages:

• High contact load capability

• Ultra-short bounce time

• Long mechanical and electrical life

• High resistance to pulsation and vibration

• Vibration resistance up to 4 g in range 0 – 1000 Hz

• Long mechanical and electrical service life

Data sheet | Thermostat, KPU

Terminology Set point

A predetermined value to which a thermostat is adjusted and at which it performs its intendedfunction.

Dierential

The dierential is the dierence between the cutin and cut-out temperatures. The dierential is necessary for satisfactory automatic operation of the controlled system.

Mechanical dierential (intrinsic dierential)

The mechanical dierential is the dierential set by the dierential spindle.

Snap function

A specic contact force is maintained until snap is initiated. The time over which contact force reaches zero is a few milliseconds; therefore, contact bounce due to vibration, for example, cannot occur at cut-out. The snap-action contact system will continue to function even when micro-welds are created between the contacts during cut-in. The force created to separate the contacts is strong enough to instantly shear o all contact surface welds that may have been created by cut-in action. These design features ensure that the cut-out setting of the KPU thermostat remains highly accurate and completely independent of the magnitude of the current load.

Reset

1. Manual reset: A unit with manual reset can only be restored to operational mode by activating the external reset button. On min. reset units the set value is equal to the cut-out value for falling temperature. On max. reset units the set value is equal to cut-out value for rising temperature.

2. Automatic reset: A unit with automatic reset is restored tooperational mode automatically.

FLA – Motor Full Load Amperes

FLA is the largest current that a motor or other device is designed to carry at rated voltage and other specic conditions. Also often called current at rated conditions.

LRA – Locked Rotor Amperes

LRA is the largest current that the motor is designed to carry with shaft or rotor immobilized.

Setting and resets Thermostats with automatic reset

Set the cut-in temperature on the “RANGE” scale. Set the dierential on the “DIFF” scale. Thecontrolled system will start at the temperature set on the RANGE scale and will be stopped when the temperature falls the number of degrees set on the DIFF scale.

Please note that the dierential scale is only areference. The exact value of distances on thescale depends on where in its range thecontrol cut-in is set. Use the dierential scale asaguide, and if precise function is required, establish the dierential setting by comparing function with an accurate thermometer in thecontrolled zone. If the compressor does not stop at the desired low temperature, check thedierential to ensure that it is not set at too high avalue.

The thermostat automatically resets and thecompressor starts once the temperature risesabove the range scale setting.

Thermostats with manual minimum reset

Set the cut-out temperature on the range scale. The dierential is xed.

Restart the compressor by pressing the reset button after the temperature of the sensor rises to a value equal to the range scale setting plus the xed dierential.

Thermostats with manual maximum reset

Set the cut-out temperature on the range scale. The dierential is xed.

Restart the compressor by pressing the reset button after the temperature of the sensor falls toa value equal to the range scale setting minus thexed dierential.

Data sheet | Thermostat, KPU

Charges

1. Vapor charge 2. Adsorption charge

Bellows

Capillary tube

Sensor

The sensor contains saturated vapor with asmallquantity of liquid. When temperature rises, liquidevaporates, and pressure inside thesensorincreases. After all of the liquid has evaporated, additional heat results in only a small pressure rise inside the element. Vapor charges are appropriate for low temperature applications and others where the bellows must be protected from deformation by

As long as the sensor is the coldest part of the thermostat, ambient temperature has no eect on regulating accuracy. Sensors with adsorption charges contain asuperheated gas together with a solid having alarge adsorption surface. The sensor can be placed in zones that are warmer or colder than the control housing and capillary tube, but variations

of more than 70 °F may inuence scaleaccuracy. ambient temperature. The sensing element must be colder than the bellows at all times so that condensation of evaporated uid occurs in the element only, and not in the bellows.

Bellows

Capillary tube

Sensor

Dimensions of KPU withoutcapillary tube

All thermostats are supplied with universal mountingbracket and mounting screws asstandardaccessory.

Approximate weight of the bracket and mounting

screws: 0.615 lb

Net weight of KPU without capillary tube: ~ 0.77 lb

Net weight of 80 in capillary tube: ~ 0.17 lb

Net weight of 200 in capillary tube: ~ 0.43 lb

Charges

KPU 61 KPU 63

Vapor charge

KPU 61 KPU 69

Vapor charge

KPU 62 KPU 68

Vapor charge

KPU 62

Adsorption charge

KPU 73

Adsorption charge

Straight capillary tube Sensing length: 15 in a = 3 1/8 in

Remote air coil a = ⁄ in b = 2 ¾ in

Room sensor C1 a = 1 ½ in b = 1 ¼ in Room sensor C2 a = 1 in b = 3 in

Double contact remote bulb a = ⁄ in b = 3 ⁄ in

NOTE!

Can not be used in sensor pocket!

Remote bulb

KPU 73, KPU 74

Adsorption charge

KPU 71, KPU 75

Adsorption charge

KPU 73, KPU 77

Adsorption charge

KPU 75

Adsorption charge

E1 a = ¼ in b = 3 ¾ in

E2 a = ⁄ in b = 4 ½ in

E3 a = ⁄ in b = 3 ⁄ in

Remote duct coil a = 1 in b = 3 ⁄ in

Danfoss KPU 74B, KPU 74, KPU 75, KPU 77, KPU Data sheet

Specifications and Main Features

Frequently Asked Questions

User Manual