Danfoss KV Data sheet

Pulse Motor

Expansion Valves

Type KV

REFRIGERATION AND AIR CONDITIONING

TECHNICAL LEAFLET

Technical leaflet	Pulse Motor Expansion Valves, Type KV

Contents	Page
Introduction......................................................................................................................................................................................	3
Features..............................................................................................................................................................................................	3
Explanation of Action....................................................................................................................................................................	4
Operation Principles..................................................................................................................................................................	4-5
Common Refrigerant Valve and Coil Specifications...........................................................................................................	6
Application Examples....................................................................................................................................................................	7
Selection Method........................................................................................................................................................................	8-9
Capacity R410A.............................................................................................................................................................................	10
CO2 Applications...........................................................................................................................................................................	11
Dimensions....................................................................................................................................................................................	12

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USCO.PD.V1.A1.22 / 521U0082

© Danfoss Inc (USCO / mks), 1-2008

Technical leaflet	Pulse Motor Expansion Valves, Type KV
Introduction	As environmental consciousness is being raised
	and global warming concerns are bringing ever
	more stringent regulations, the demand is
	quickly growing for energy-saving cooling and
	heating devices in household and commercial
	applications, including cold storage warehouses
	and, rapid freezing devices.
	The KV series of stepper motor expansion valves
	have been solidly respected in Japanese markets
	since 1982. Danfoss Saginomiya offers KV series
	pulse motor expansion valves for numerous
	applications. KV reliability has been extensively
	field proven.

Features	• Wide selection for refrigeration and air
	conditioning applications
	• Compatible with various refrigerants:
	R-410A, R-407C, R-134a, R-404A, R-22
	• Stepper motor drive provides high-precision
	flow control
	• A range of full closing valve types is available
	that generally require no solenoid valve
	• High resolution: 480 steps from fully closed
	to fully open

•Compact and lightweight design

•Power-saving design requires no energy for stopping.

•Ideally suited for microcomputer control

•Unipolar drive system (for bipolar drive, please contact us)

•Bi-flow design for heat pump applications

•UKV, SKV, VKV, AKV: UL recognized

•KV valves have excellent flow characteristics, including high resolution at low load.

In KV valves that have an inflected flow characteristic as shown in (a) and (c), the flow per pulse has one rate for low flow and a higher rate for greater flow. With these valves, fine control can be accomplished with a low load (low flow). Full closing KV valves having a flow characteristic (b), (c) are available with inflected flow characteristic or continuous flow characteristic, the latter having very nearly the same change in flow rate per pulse.

a	b	c
Max	Max	Max
Flow	Flow	Flow

0

Pulse

480

0

Pulse

480

0

Pulse

480

•Long valve lift range results in a wider range of controllable capacity

3

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<![endif]>Capacity (U.S.R.T)

0

Our mechanical		Our pulse motor
expansion valves		expansion valves
	3.0

2.62 VPX-3415BPC

1.40

VPX-3408BPC

PKV-18BS

0.87 VPX-3405BPC

0.52 VPX-3403BPC

(capacity ..... R407C)

As can be seen in the diagram above, pulse motor expansion valves have a much greater range than mechanical valves.

© Danfoss Inc (USCO / mks), 1-2008

USCO.PD.V1.A1.22 / 521U0082

3

Technical leaflet	Pulse Motor Expansion Valves, Type KV
Explanation of Action	In operation of the KV valve, the magnet-needle valve assembly is rotated by the stepper motor
	(principle described in next paragraph) and by means of a screw structure has linear motion, opening
	and closing to regulate refrigerant flow. This simple structure results in compact products.
	Magnet
	Coil	Male screw
		Female screw
		Needle valve
		Body
		B
		Fluid direction
		A

Sectional diagram of KV series

Operation Principle I
	Figs.1-1 and 1-2 show a vertical cross section of the coils (upper coil (A and A) and lower coil (B and
	B). Each coil comprises a clockwise winding A, B and a counterclockwise winding A, B. Each coil has 3
	terminals. Fig.1-3 shows the arangement of the stators that surround the armature. The polarities of the
	magnetic poles change depending on the direction of current flow.

Upper coil

Housing

N	N
S	S

Stator

Lower coil

Fig.1-1

A Phase

A,B Phase

B Phase

Phase

A,B

Fig.1-3

Upper coil

A

	COM	Connector No.		ON
		1	A Phase
				OFF
	A	2	B Phase
		3	A Phase
	Lower coil	4	B Phase
	B	5	COM.(
				Valve operation Valve opens
	COM			Valve is closed
	B	Fig.1-4 Excitation sequence
			(1-2 phase excitation)
	Fig.1-2
4	USCO.PD.V1.A1.22 / 521U0082			© Danfoss Inc (USCO / mks), 1-2008