Danfoss KV Data sheet
REFRIGERATION AND
AIR CONDITIONING
Pulse Motor
Expansion Valves
Type KV
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
Applications .......................................................................................................................................................................... 11
CO
2
Dimensions ....................................................................................................................................................................................12
2 USCO.PD.V1.A1.22 / 521U0082 © Danfoss Inc (USCO / mks), 1-2008
Technical leaflet Pulse Motor Expansion Valves, Type KV
4800
Pulse
Flow
Max
4800
Pulse
Flow
Max
4800
Pulse
Flow
Max
a b c
VPX-3415BPC
2.62
PKV-18BS
Capacity (U.S.R.T)
0
3
VPX-3408BPC
1.40
VPX-3405BPC
0.87
VPX-3403BPC
0.52
Our mechanical
expansion valves
Our pulse motor
expansion valves
(capacity ..... R407C)
3.0
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
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•
High resolution: 480 steps from fully closed •
to fully open
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.
© Danfoss Inc (USCO / mks), 1-2008 USCO.PD.V1.A1.22 / 521U0082 3
As can be seen in the diagram above, pulse motor expansion valves have a much greater range than
mechanical valves.
Long valve lift range results in a wider range of controllable capacity•
Technical leaflet Pulse Motor Expansion Valves, Type KV
Sectional diagram of KV series
B
A
Magnet
Coil Male screw
Female screw
Needle valve
Body
Fluid direction
Lower coil
Stator
Upper coil
Housing
SS
NN
COM
COM
A
A
B
B
A Phase A,B Phase A,B PhaseB Phase
Upper coil
Lower coil
Ｓ
Ｎ
Ｓ
Ｎ
Ｎ
Ｓ
Ｎ
Ｓ
Ｓ
Ｎ
Ｓ
Ｎ
Fig.1-1
Fig.1-2
Fig.1-3
Connector No.
ON
OFF
1
A Phase
2
B Phase
A Phase
B Phase
3
4
5 COM.(＋）
Fig.1-4 Excitation sequence
(1-2 phase excitation)
Valve operation Valve opens
Valve is closed
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.
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.
4 USCO.PD.V1.A1.22 / 521U0082 © Danfoss Inc (USCO / mks), 1-2008
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