MAKING MODERN LIVING POSSIBLE
Fitters Notes
Hints and tips for the installer
REFRIGERATION &
aIR CONDITIONING DIVISION
Manual
This Fitters Notes, gives practical hints about Danfoss commercial refrigeration controls (mechanical) and Danfoss compressors.
If you need further information about the Danfoss product range please contact your dealer or local Danfoss agency. You can also find some very useful information on our web site:
www.danfoss.com
We hope that this book will help you in your daily work.
Danfoss A/S
Fitters notes
Chapter 1 . . . . . . . . . Thermostatic expansion valves . . . . . . . . . . . . . page 3
Chapter 2 . . . . . . . . . Solenoid valves . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .page 13
Chapter 3 . . . . . . . . . Pressure controls . . . . . . . . . . . . . . . . . page 19
Chapter 4 . . . . . . . . . Thermostats . . . . . . . . . . . . . . . . . page 27
Chapter 5 . . . . . . . . . Pressure regulators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .page 35
Chapter 6 . . . . . . . . . Water valves . . . . . . . . . . . . . . . . . page 45
Chapter 7 . . . . . . . . . Filter driers & sight glasses . . . . . . . . . . . . . . .page 51
Chapter 8 . . . . . . . . . Danfoss compressors . . . . . . . . . . . . . . . . . page 61
Chapter 9 . . . . . . . . . Practical tips . . . . . . . . . . . . . . . . . page 125
Chapter 10 . . . . . . . . Trouble shooting . . . . . . . . . . . . . . . . . page 145
<![if ! IE]> <![endif]>valves expansion |
<![if ! IE]> <![endif]>Thermostatic |
<![if ! IE]> <![endif]>valves Solenoid |
|
<![if ! IE]> <![endif]>controls Pressure |
|
<![if ! IE]> <![endif]>Thermostats |
|
<![if ! IE]> <![endif]>regulators |
<![if ! IE]> <![endif]>Pressure |
<![if ! IE]> <![endif]>valves Water |
|
<![if ! IE]> <![endif]>glasses sight |
<![if ! IE]> <![endif]>& driers Filter |
<![if ! IE]> <![endif]>compressors |
<![if ! IE]> <![endif]>Danfoss |
<![if ! IE]> <![endif]>tips Practical |
|
<![if ! IE]> <![endif]>shooting Trouble |
|
© Danfoss A/S (AC-DSL/MWA), 10 - 2006 |
DKRCC.PF.000.G1.02 / 520H1459 |
1 |
Fitters notes |
Thermostatic expansion valves |
|
|
Contents
Page
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5 Superheat . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5 Subcooling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 External pressure equalization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 Charges . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Universal charge . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . |
. |
.6 |
MOP charge . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . |
. |
. 6 |
MOP ballast charge . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . |
. |
.7 |
Thermostatic expansion valve selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7 Identification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8
Setting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . |
. . .9 |
Orifice assembly replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . |
10 |
Danfoss product range . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . |
. 11 |
<![endif]>Thermostatic valves expansion
© Danfoss A/S (AC-DSL/MWA), 10 - 2006 |
DKRCC.PF.000.G1.02 / 520H1459 |
3 |
Notes
DKRCC.PF.000.G1.02 / 520H1459 |
© Danfoss A/S (AC-DSL/MWA), 10 - 2006 |
Fitters notes |
Thermostatic expansion valves |
|
Introduction |
A thermostatic expansion valve is built up around |
|
|
||
|
a thermostatic element (1) separated from the |
|
|
valve body by a diaphragm. |
|
|
A capillary tube connects the element to a bulb |
|
|
(2) and a valve body with valve seat (3) and a |
|
|
spring (4). |
|
|
A thermostatic expansion valve works like this: |
|
|
The function of a thermostatic expansion valve is |
|
|
determined by three fundamental pressures: |
|
|
P1: Bulb pressure which acts on the upper |
|
|
surface of the diaphragm, in the valve |
|
|
opening direction. |
|
|
P2: Evaporating pressure which acts on the |
|
|
underside of the diaphragm, in the valve |
|
|
closing direction. |
|
|
P3: Spring pressure which also acts on the |
|
|
underside of the diaphragm, in the valve |
|
|
closing direction. |
|
|
When the expansion valve regulates, balance is |
|
|
created between bulb pressure on one side of the |
|
|
diaphragm and evaporating pressure plus spring |
|
|
force on the other side. |
|
|
The spring is used to set superheat. |
|
|
|
|
Ad0-0001
Superheat |
Superheat is measured at the point where the |
|
bulb is located on the suction line and is the |
|
difference between the temperature at the |
|
bulb and the evaporating pressure/evaporating |
|
temperature at the same point. |
|
Superheat is measured in Kelvin (K) and is used as |
|
a signal to regulate liquid injection through the |
|
expansion valve. |
Ad0-0012
Subcooling |
Subcooling is defined as the difference between |
|
condensing pressure/temperature and liquid |
|
temperature at the expansion valve inlet. |
Subcooling is measured in Kelvin (K). Subcooling of the refrigerant is necessary to avoid vapour bubbles in the refrigerant ahead of the expansion valve.
Vapour bubbles in the refrigerant reduce capacity in the expansion valve and thereby reduce liquid supply to the evaporator.
Subcooling of 4-5K is adequate in most cases.
Ad0-0015
<![endif]>Thermostatic valves expansion
© Danfoss A/S (AC-DSL/MWA), 10 - 2006 |
DKRCC.PF.000.G1.02 / 520H1459 |
5 |
Fitters notes |
Thermostatic expansion valves |
|||||
|
|
|
|
|
|
|
External pressure |
|
Expansion valves with external pressure equali- |
|
|
|
|
|
|
|
||||
equalization |
|
zation must always be used if liquid distributors |
|
|
|
|
|
|
are installed. |
|
|
|
|
|
|
Typically, the use of distributors gives a pressure |
|
|
|
|
|
|
drop of 1 bar across distributor and distribution |
|
|
|
|
|
|
tubes. |
|
|
|
|
|
|
Expansion valves with external pressure equali- |
|
|
|
|
|
|
zation should always be used in refrigeration |
|
|
|
|
|
|
systems with heavy evaporators or plate |
|
|
|
|
|
|
exchangers, where normally the pressure drop |
|
|
|
|
|
|
will be greater than pressure corresponding to |
|
|
|
|
|
|
|
|
|||
|
|
2K. |
Ad0-0016 |
|||
|
|
|
|
|
|
|
Charges |
|
|
|
|
||
|
Thermostatic expansion valves can contain one |
|||||
|
|
of three different types of charge: |
||||
|
1. |
Universal charge |
||||
|
2. |
MOP charge |
||||
|
3. |
MOP charge with ballast, standard for Danfoss |
||||
|
|
|
expansion valves with MOP. |
|||
Universal charge |
|
Expansion valves with Universal charge are used |
|
|
||
|
|
|
||||
|
|
in most refrigeration systems where there is no |
|
|
||
|
|
pressure limitation requirement and where the |
|
|
||
|
|
bulb can be located warmer than the element |
|
|
||
|
|
or at high evaporating temperature/evaporating |
|
|
||
|
|
pressure. |
|
|
||
|
|
Universal charge means that there is liquid |
|
|
||
|
|
charge in the bulb. The amount of charge is so |
|
|
||
|
|
large that charge remains in the bulb irrespective |
|
|
||
|
|
of whether the element is colder or warmer than |
|
|
||
|
|
the bulb. |
|
|
||
|
|
|
|
|
|
|
MOP charge |
Expansion valves with MOP charge are typically |
|
used on factory-made units where suction |
|
pressure limitation on starting is required, e.g. |
|
in the transport sector and in air conditioning |
|
systems. |
|
All expansion valves with MOP have a very small |
|
charge in the bulb. |
|
This means that the valve or the element must be |
|
located warmer than the bulb. If it is not, charge |
|
can migrate from the bulb to the element and |
|
prevent the expansion valve from functioning. |
Ad0-0017
Ad0-0018
MOP charge means limited liquid charge in the bulb.
“MOP” stands for Maximum Operating Pressure and is the highest suction pressure/ evaporating pressure permissible in the evaporator/suction line.
The charge will have evaporated when the temperature reaches the MOP point. Gradually, as the suction pressure rises, the expansion valve begins to close at approx. 0.3/0.4 bar below the MOP point. It becomes completely closed when the suction pressure is the same as the MOP point.
MOP is often called “Motor Overload Protection”.
DKRCC.PF.000.G1.02 / 520H1459 |
© Danfoss A/S (AC-DSL/MWA), 10 - 2006 |
Fitters notes |
Thermostatic expansion valves |
|
|
MOP ballast charge |
Expansion valves with MOP ballast charges are |
|
used mainly in refrigeration systems with “high- |
|
dynamic” evaporators, e.g. in air conditioning |
|
systems and plate heat exchangers with high |
|
heat transfer. |
With MOP ballast charge, up to 2 - 4 K less superheat can be obtained than with other types of charge.
The bulb in a thermostatic expansion valve contains a material of high porosity and large surface area in relation to weight.
Ad0-0021
MOP charge with ballast has a damping effect on expansion valve regulation.
The valve opens slowly as bulb temperature rises and closes quickly as bulb temperature fails.
Thermostatic expansion |
The thermostatic expansion valve can be selec- |
|
|
|
valve selection |
ted when the following are known: |
|
|
|
|
|
Refrigerant |
|
Subcooling |
|
|
|
||
|
|
Evaporator capacity |
|
Pressure drop across valve |
|
|
|
||
|
|
Evaporating pressure |
|
Internal or external pressure equalization |
|
|
|
||
|
|
|
||
|
|
Condensing pressure |
|
|
|
|
|
|
Identification |
The thermostatic element is fitted with a laser |
|
||
|
engraving on top of the diaphragm. |
|
||
|
The code refers to the refrigerant for which the |
|
||
|
valve is designed: |
|
||
|
L |
= |
R410A |
|
|
N |
= |
R134a |
|
|
S |
= |
R404A/ R507 |
|
|
X |
= |
R22 |
|
|
Z |
= |
R407C |
|
|
This engraving gives valve type (with code |
|
||
|
number), evaporating temperature range, MOP |
|
||
|
point, refrigerant, and max. working pressure, |
|
||
|
PS/MWP. |
|
|
|
|
With TE 20 and TE 55 the rated capacity is |
|
||
|
stamped on a band label fastened to the valve. |
|
||
|
|
|
|
Ad0-0019 |
|
The orifice assembly for T2 and TE2 is marked |
|
||
|
with the orifice size (e.g. 06) and week stamp + |
|
||
|
last number in the year (e.g. 279). |
|
||
|
The orifice assembly number is also given on the |
|
||
|
lid of its plastic container. |
Ad0-0023 |
||
|
|
|
|
On TE 5 and TE 12 the upper stamp (TE 12) indicates for which valve type the orifice can be used. The lower stamp (01) is the orifice size.
On TE 20 and TE 55 the lower stamp (50/35 TR N/B) indicates the rated capacity in the two evaporating temperature ranges N and B, and the refrigerant. (50/35 TR = 175 kW in range N and 123 kW in range B).
The upper stamp (TEX 55) refers to the valve type for which the assembly can be used.
Ad0-0020
<![endif]>Thermostatic valves expansion
© Danfoss A/S (AC-DSL/MWA), 10 - 2006 |
DKRCC.PF.000.G1.02 / 520H1459 |
7 |
Fitters notes |
Thermostatic expansion valves |
Installation |
The expansion valve must be installed in the |
|
liquid line, ahead of the evaporator, with its |
|
bulb fastened to the suction line as close to the |
|
evaporator as possible. |
|
If there is external pressure equalization, the |
|
equalizing line must be connected to the suction |
|
line immediately after the bulb. |
The bulb is best mounted on a horizontal suction line tube and in a position corresponding to between 1 o’clock and 4 o’clock.
Location depends on the outside diameter of the tube.
Note:
The bulb must never be located at the bottom of the suction line due to the possibility of oil laying in the bottom of the pipe causing false signals.
The bulb must be able to sense the temperature of the superheated suction vapour and must therefore not be located in a position that will expose it to extraneous heat/cold.
If the bulb is exposed to a warm air current, insulation of the bulb is recommended.
The Danfoss bulb strap allows a tight and secure fitting of the bulb to the tube, thereby securing that the bulb has ultimate thermal contact to the suction tube. The TORX design of the screw makes it easy for the fitter to transfer the torque from the tool to the screw without having to press the tool into the screw slot. Furthermore, with the TORX slot design, there is no risk of damaging the screw slot.
The bulb must not be installed after a heat exchanger because in this position it will give false signals to the expansion valve.
Ad0-0002
Ad0-0003
Ad0-0004
Ad0-0005
The bulb must not be installed close to components of large mass as this also will give rise to false signals to the expansion valve
Ad0-0006
8 |
DKRCC.PF.000.G1.02 / 520H1459 |
© Danfoss A/S (AC-DSL/MWA), 10 - 2006 |
Fitters notes |
Thermostatic expansion valves |
|
|
Installation (cont.) |
As previously mentioned, the bulb must be |
<![if ! IE]> <![endif]>valvesexpansion |
<![if ! IE]> <![endif]>Thermostatic |
|
installed to the horizontal part of the suction line |
||
|
|
|
|
|
immediately after the evaporator. It must not be |
|
|
|
installed to a collection tube or a riser after an oil |
|
|
|
pocket. |
|
|
|
|
Ad0-0007 |
|
The expansion valve bulb must always be installed ahead of any liquid lock.
Ad0-0008
Setting |
The expansion valve is supplied with a factory |
|
setting suitable for most applications. |
If necessary, readjustment can be made using the setting spindle on the valve.
Turning the spindle clockwise increases the expansion valve superheat and turning it counterclock-wise reduces it.
For T /TE 2, one turn of the spindle produces a change of approx. 4K in the superheat at 0°C evaporating temperature.
Ad0-0009
© Danfoss A/S (AC-DSL/MWA), 10 - 2006 |
DKRCC.PF.000.G1.02 / 520H1459 |
9 |
Fitters notes |
Thermostatic expansion valves |
|
|
Setting (cont.) |
For TE 5 and following sizes, one turn of the |
|
spindle produces a change of approx. 0.5K in |
|
the superheat at 0°C evaporating temperature. |
For TUA and TUB, one turn of the spindle produces a change of approx. 3K in the superheat at 0°C evaporating temperature.
Ad0-0010
Hunting in the evaporator can be eliminated by the following procedure:
Increase the superheat by turning the expansion valve setting spindle well to the right (clockwise) so that hunting stops. Then turn the setting spindle in counter-clockwise steps so that hunting again occurs.
From this position, turn the spindle about once clockwise (but only 1/4 turn for T /TE 2 valves).
On this setting the refrigeration system will not |
|
hunt and the evaporator is fully utilized. |
|
A variation of 1 K in superheat is not regarded as |
|
hunting. |
Ad0-0011 |
|
If the superheat in the evaporator is too high, the reason might be an inadequate supply of liquid refrigerant.
The superheat can be reduced by turning the expansion valve setting spindle counterclockwise in steps until hunting is observed.
From this setting, the spindle must be turned about once clockwise (but only 1/4 turn for T/TE 2). This setting fully utilizes the evaporator.
A variation of 1 K in superheat is not regarded as hunting.
|
|
Ad0-0013 |
Orifice assembly |
If the evaporator continues to hunt, regardless of |
|
replacement |
the superheat setting, the valve capacity might |
|
|
be too high and the orifice assembly, or the valve, |
|
|
needs replacing with a smaller one. |
|
|
If the evaporator superheat is too high the valve |
|
|
capacity is too low and the orifice assembly must |
|
|
be replaced with a larger one. |
|
|
TE, T2, TUA, TCAE valves are supplied with an |
|
|
interchangeable orifice. |
|
|
|
Ad0-0014 |
10 |
DKRCC.PF.000.G1.02 / 520H1459 |
© Danfoss A/S (AC-DSL/MWA), 10 - 2006 |
Fitters notes |
Thermostatic expansion valves |
|
|
|
|
|
|
Danfoss product range |
Danfoss offers a comprehensive range of |
|
|
Thermostatic expansion |
thermostatic expansion valves with capacities |
|
|
valves |
from 0.4 to 1083 kW (R134a). |
|
|
|
|
|
|
|
T/TE 2 valves have a brass housing and flare/ |
TDE valves have a brass housing and copper |
|
|
flare or solder/flare connections. |
solder connections. |
|
|
Rated capacity: 0.4 - 10.5 kW (R134a). |
Rated capacity: 10.5 - 140 kW (R407C) |
|
|
|
|
|
|
TUA, TUB, TUC valves have a stainless steel |
The valves are supplied with a fixed orifice and |
|
|
adjustable superheat. |
||
|
housing and stainless steel/copper bimetal |
|
|
|
solder connections. |
TE 5 - TE 55 valves have a brass housing. |
|
|
Rated capacity: 0.5 - 12 kW (R134a). |
||
|
The valves are supplied as a part programme |
||
|
|
|
|
|
The valves can be supplied with or without |
consisting of valve housing, orifice and thermo- |
|
|
external pressure equalization. |
static element. |
|
|
|
TUA has an interchangeable orifice |
The valve housing is available in a straightway |
|
|
||
|
|
||
|
|
assembly and adjustable superheat. |
or angleway version with solder, flare and flange |
|
|
TUB has a fixed orifice and adjustable |
connections. |
|
|
||
|
|
||
|
|
superheat. |
Rated capacity: 12.9 - 220 kW (R134a). |
|
|
TUC has a fixed orifice and factory set |
|
|
|
The valves are supplied with external pressure |
|
|
|
||
|
|
||
|
|
superheat. |
|
|
|
equalization. |
|
|
TUB and TUC are primarily for OEM customers. |
||
|
|
||
|
All TUB and TUC valves can be replaced by TUA |
|
|
|
valves. |
PHT 85 - 300 valves are supplied as a part |
|
|
|
|
programme consisting of valve housing, flanges, |
|
TCAE, TCBE, TCCE valves have a stainless steel |
orifice and thermostatic element. |
|
|
Rated capacity: 55 - 1083 kW (R134a). |
||
|
housing and stainless steel/copper bimetal |
||
|
|
||
|
solder connections. |
|
Rated capacity: 12 - 18 kW (R134a).
The valves are designed as the TU valves but with a higher capacity.
The valves are supplied with external pressure equalization.
TRE valves have a brass housing and stainless steel/copper bimetal connections.
Rated capacity: 18 - 196 kW (R134a).
The valves are supplied with a fixed orifice and adjustable superheat.
For further information consult the internet or the catalogue material.
<![endif]>Thermostatic valves expansion
© Danfoss A/S (AC-DSL/MWA), 10 - 2006 |
DKRCC.PF.000.G1.02 / 520H1459 |
11 |
Fitters notes |
Solenoid valves |
|
|
Contents |
|
|
|
|
|
Page |
|
Installation . . . . . . . . . |
. . . . . . . . . . . . . . . . . . . . |
. . . . . . . . . . |
. . . |
. |
. 15 |
||
EVRA 32 & 40 precautions |
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . |
. . . . . . . . . . . . . . . . . . . |
. |
. . . . . |
. |
. . |
. 15 |
When pressure testing . . |
. . . . . . . . . . . . . . . . . . . . |
. . . . . . . . . |
. |
. . |
. |
. |
16 |
The coil . . . . . . . . . . . |
. . . . . . . . . . . . . . . . . . . . |
. . . . . . . . . |
. |
. . |
. |
. |
17 |
The correct product . . . . . |
. . . . . . . . . . . . . . . . . . . . |
. . . . . . . . . |
. |
. . |
. |
. |
18 |
|
|
|
|
|
|
|
<![if ! IE]> <![endif]>valves Solenoid |
© Danfoss A/S (AC-DSL/MWA), 10 - 2006 |
DKRCC.PF.000.G1.02 / 520H1459 |
13 |
Notes
14 |
DKRCC.PF.000.G1.02 / 520H1459 |
© Danfoss A/S (AC-DSL/MWA), 10 - 2006 |
Fitters notes |
Solenoid valves |
|
|
||||
|
|
|
|
|
|
|
|
Installation |
All EVR/EVRA, and EVH types solenoid valves |
|
|
|
|
||
|
|
|
|
|
|
||
|
operate only when installed correctly in the |
|
|
|
|
||
|
direction of flow, i.e. in the direction indicated by |
|
|
|
|
||
|
the arrow. |
|
|
|
|
||
|
Normally, solenoid valves installed ahead of a |
|
|
|
|
||
|
|
|
|
|
|
|
|
|
|
|
|
||||
|
thermostatic expansion valve must be close to |
|
|
|
|
||
|
that valve. |
|
|
|
|
||
|
|
<![if ! IE]> <![endif]>valves Solenoid |
|||||
|
This avoids liquid hammer when the solenoid |
|
|
|
|||
|
valve opens. |
|
|
|
|||
|
|
|
|
|
|
|
|
|
|
|
Af0_0001 |
|
|||
|
|
|
|
|
|||
|
Ensure that pipes around the valve are properly |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
installed so that no fracture can occur. |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Af0_0003 |
|
|
||
|
Brazing/welding EVR/EVRA and EVH solenoid |
|
|
|
|||
|
|
|
|
|
|
||
|
valves does not normally necessitate dismantling, |
|
|
|
|||
|
provided steps are taken to avoid heating the |
|
|
|
|||
|
valve. |
|
|
|
|||
|
Note! Always protect the armature tube against |
|
|
|
|||
|
weld spatter. |
|
|
|
|||
EVRA 32 & 40 precautions |
After tacking the valve to the pipe, remove the |
|
|
|
|||
|
valve body to protect O-rings and gaskets against |
|
|
|
|||
|
heat. In installations with welded steel pipe, a |
|
|
|
|||
|
FA type strainer or similar mounted ahead of the |
|
|
|
|||
|
solenoid valve is recommended. (On new plant, |
|
|
|
|||
|
flushing out before starting up is recommended). |
|
|
|
|||
|
|
Af0_0004 |
|
|
|||
|
|
|
|
|
|
|
|
© Danfoss A/S (AC-DSL/MWA), 10 - 2006 |
DKRCC.PF.000.G1.02 / 520H1459 |
15 |
Fitters notes |
Solenoid valves |
When pressure testing |
All solenoid valves in the system must be open, |
|
|
||
|
either by applying voltage to the coils or by |
|
|
opening the valves manually (provided a manual |
|
|
operation spindle is fitted). |
|
|
Remember to screw the spindle back before |
|
|
starting up, otherwise the valve will be unable to |
|
|
close. |
|
|
|
|
Af0_0005
Always use counter force when finally tightening the solenoid valve on pipes, i.e. two spanners on the same side of the valve.
Af0_0006
16 |
DKRCC.PF.000.G1.02 / 520H1459 |
© Danfoss A/S (AC-DSL/MWA), 10 - 2006 |
Fitters notes |
Solenoid valves |
|
|
The coil |
When fitting the coil, it has merely to be pressed |
|
down over the armature tube until a click is |
|
heard. This means that the coil has been correctly |
|
fitted. |
Note: Remember to fit an O-ring between valve body and coil.
Be sure that the O-ring is smooth, not damaged |
|
<![if ! IE]> <![endif]>Solenoid |
and that the surface is free from paint or any |
|
|
|
|
|
other material. |
|
|
Note: The O-ring must be changed at service. |
|
<![if ! IE]> <![endif]>valves |
|
Af0_0018 |
|
|
|
|
The coil can be removed by inserting a |
|
|
screwdriver between valve body and coil. The |
|
|
screwdriver can then be used as a lever to loosen |
|
|
the coil. |
|
|
|
Af0_0019 |
|
Be careful with cable entries. It must not be possible for water to enter the terminal box. The cable must be led out via a drip loop.
Af0_0009
The entire cable circumference must be retained by the cable entry.
Therefore, always use round cable (which is the only type of cable that can be sealed effectively).
Af0_0010
Be aware of the colour of leads in the cable.
Yellow/green is always earth.
Leads of one colour are either phase or neutral.
Af0_0011
© Danfoss A/S (AC-DSL/MWA), 10 - 2006 |
DKRCC.PF.000.G1.02 / 520H1459 |
17 |
Fitters notes |
Solenoid valves |
|
|
The coil (cont.) |
When removing a coil it might be necessary to |
|
use hand tools, e.g. two screwdrivers. |
Af0_0012 |
The correct product |
Make sure that coil data (voltage and frequency) |
|
|
||
(The “old” coil type) |
and supply voltage correspond. If they do not, |
|
|
the coil might burn out. Always ensure that valve |
|
|
and coil match each other. |
|
|
When replacing a coil in an EVR 20 NC |
|
|
(NC = normally closed) note: |
|
|
- A valve body using an a.c. coil has a square |
|
|
armature. |
|
|
- A valve body using a d.c. coil has a round |
Af0_0013 |
|
armature. |
|
|
Fitting the wrong coil results in a lower MOPD. |
|
|
See data on the top nut. As far as possible, always |
|
|
choose single-frequency coils. These give off |
|
|
less heat than double-frequency coils. |
|
|
Use NC (normally closed) solenoid valves for |
|
|
systems in which the valve must remain closed |
|
|
(de-energised) for most of the operating time. |
|
|
Use NO (normally open) solenoid valves for |
Af0_0014 |
|
systems in which the valve must remain open |
|
|
|
|
|
(de-energised) for most of the operating time. |
|
|
Never replace an NO (normally open) solenoid |
|
|
valve with an NC (normally closed) valve - or vice |
|
|
versa. |
|
|
|
|
(The new “clip-on” coil type) |
Two labels are supplied with each clip-on coil |
|
|
||
|
(see illustration). |
|
|
The adhesive label is for attaching to the side of |
|
|
the coil, while the other, perforated label should |
|
|
be placed over the armature tube before the coil |
|
|
is clicked into position. |
|
|
|
Af0_0015 |
Af0_0020
18 |
DKRCC.PF.000.G1.02 / 520H1459 |
© Danfoss A/S (AC-DSL/MWA), 10 - 2006 |
Fitter notes |
Pressure controls |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Contents |
|
|
|
Page |
|||
|
Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 |
||||||
|
Placing of surplus capillary tube . . . . . . . . . . . . . . . . . . . . . . |
. . . . . . . . . |
. |
. |
22 |
|
|
|
Setting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . |
. . . . . . . . . . . . . . . . . . |
. . |
. . |
. 22 |
|
|
|
Low-pressure control . . . . . . . . . . . . . . . . . . . . . . . . . |
. . . . . . . . . |
. |
. |
. 22 |
|
|
|
High-pressure control . . . . . . . . . . . . . . . . . . . . . . . . . |
. . . . . . . . . |
. |
. |
22 |
|
|
|
Example with four compressors in parallel (R404A) . . . . . . . . . . . |
. . . . . . . . . |
. |
. |
23 |
|
|
|
Setting LP for outdoor location . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 |
||||||
|
Indicative evaporating pressures (pe) for different types of systems . . . . . |
. . . . . . . . . |
. |
. |
23 |
|
|
|
Test of contact function . . . . . . . . . . . . . . . . . . . . . . . . . . |
. . . . . . . . . |
. |
. |
24 |
|
|
|
The correct pressure control for your system . . . . . . . . . . . . . . . . |
. . . . . . . . . |
. |
. |
25 |
|
|
|
|
<![if ! IE]> <![endif]>controls Pressure |
|||||
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
© Danfoss A/S (AC-DSL/MWA), 10 - 2006 |
DKRCC.PF.000.G1.02 / 520H1459 |
19 |
Notes
20 |
DKRCC.PF.000.G1.02 / 520H1459 |
© Danfoss A/S (AC-DSL/MWA), 10 - 2006 |
Fitter notes |
Pressure controls |
||||
|
|
|
|
|
|
Installation |
Mount the KP pressure control on a bracket or on |
|
|
||
|
|
|
|
||
|
a completely flat surface. |
|
|
||
|
The pressure control can also be mounted on the |
|
|
||
|
compressor itself. |
|
|
||
|
In unfavourable conditions, an angle bracket |
|
|
||
|
could amplify vibration in the mounting plane. |
|
|
||
|
Therefore, always use a wall bracket where strong |
|
|
|
|
|
|
||||
|
vibration occurs. |
|
|
|
|
|
|
|
|
|
|
Al0_0001
If the risk of water droplets or water spray is |
|
|
present, the accompanying top plate should be |
|
|
used. The plate increases the grade of enclosure |
|
|
to IP 44 and is suitable for all KP pressure controls. |
|
|
To obtain IP 44, the holes in the backplate of the |
|
|
control must be covered by mounting on either |
|
|
an angle bracket (060-105666) or a wall plate |
|
|
(060-105566). |
|
|
The top plate is supplied with all units incor- |
|
|
porating automatic reset. It can also be used on |
|
|
units with manual reset, but in that case must |
|
|
be purchased separately (code no.: for single unit, |
|
|
060-109766; for dual unit, 060-109866). |
|
|
If the unit is to be used in dirty conditions or |
|
|
Al0_0007 |
||
where it might be exposed to heavy spray - |
||
|
||
from above or from the side - it should be fitted |
|
|
|
||
with a protective cap. The cap can be used |
|
|
together with either an angle bracket or a wall |
|
|
bracket. |
|
|
|
|
Al0_0008
If the unit risk being exposed to heavy water influence a better grade of enclosure can be achieved when mounting the product in a special IP 55 enclosure.
The IP 55 enclosure is available for both single unit (060-033066) and dual unit (060-035066).
Ak0_0020
<![if ! IE]> <![endif]>controls Pressure |
© Danfoss A/S (AC-DSL/MWA), 10 - 2006 |
DKRCC.PF.000.G1.02 / 520H1459 |
21 |
Fitter notes |
Pressure controls |
|
|
Installation (cont.)
Placing of surplus capillary tube
The pressure connection of the control must always be fitted to the pipe in such a way that liquid cannot collect in the bellows. This risk is present especially when:
the unit is located in a low ambient condition, e.g. in an air current,
the connection is made on the underside of the pipe.
Such liquid could damage the high-pressure control.
Consequently, compressor pulsation would not be damped and might give rise to contact chatter.
Al0_0009
Surplus capillary tube can fracture if vibration occurs and might lead to complete loss of system charge. It is therefore very important that the following rules are observed:
When mounting direct on compressor: Secure the capillary tube so that the compressor/control installation vibrates as a whole. Surplus capillary tube must be coiled and bound.
Note:
According to EN rules it is not allowed to use capillary tube for connecting safety pressure controles. In such case a 1/4 inch tube is prescribed.
Other types of mounting:
Coil surplus capillary tube into a loose loop. Secure the length of capillary tube between compressor and loop to the compressor.
Secure the length of capillary tube between loop and pressure control to the base on which the pressure control is mounted.
In case of very strong vibrations, Danfoss steel capillary tubes with flare connection are
recommended: |
|
|
Code no. 0.5 m |
= |
060-016666 |
Code no. 1.0 m |
= |
060-016766 |
Code no. 1.5 m |
= |
060-016866 |
Al0_0010 |
Al0_0011 |
Setting |
KP pressure controls can be preset using a com- |
|
|
|
|
|
|
||
|
pressed air cylinder. Ensure that the change-over |
|
|
|
|
contacts are correctly connected for the required |
|
|
|
|
function. |
|
|
|
|
|
|
|
|
Low-pressure control |
Set the start pressure (CUT IN) on the range scale |
|
|
|
|
(A). Then set the differential on the differential |
|
|
|
|
scale (B). |
|
|
|
|
Stop pressure = CUT IN minus DIFF. |
|
|
|
High-pressure control |
Set the stop pressure (CUTOUT) on the range |
|
|
|
|
scale (A). The set the differential on the |
|
|
|
|
differential scale (B). |
|
|
|
|
Start pressure = CUT OUT minus DIFF. |
|
|
|
|
|
Al0_0012 |
||
|
Remember: The scales are indicative only. |
22 |
DKRCC.PF.000.G1.02 / 520H1459 |
© Danfoss A/S (AC-DSL/MWA), 10 - 2006 |
Fitter notes |
Pressure controls |
|
|
Example with four compressors |
Medium: ice cream at –25°C, |
in parallel (R404A) |
t0 ≈ –37°C, |
|
p0 ≈ –0.5 bar, |
|
∆p suction line corresponding to 0.1 bar. |
|
Each pressure control (e.g. KP 2) must be set |
|
individually in accordance with the following |
|
table. |
Compressor |
CUT OUT |
CUT IN |
1 |
–0.05 bar |
0.35 bar |
2 |
0.1 bar |
0.5 bar |
3 |
0.2 bar |
0.6 bar |
4 |
0.35 bar |
0.75 bar |
The pressure control must be mounted in such a way that liquid cannot collect in the bellows.
Example:
Lowest occurring temperature around the compressor –20°C means, for R404A, a pressure of 1 bar. CUT IN must be set at –24°C (corresponding to 1.6 bar).
Al0_0013
Room temp. (tr) |
System type |
Difference |
Evaporating |
RH |
Setting of KP2/KP1 |
||
|
|
between te |
pressure (pe) |
[%] |
(cut in - cut out) |
||
|
|
and tmedia (air) |
|
|
D = Operating press. cont. |
||
|
|
|
|
|
|
S = Safety press. cont. |
|
+0.5°/+2°C |
Fan-cooled |
10K |
1.0 - 1.1 bar |
85 |
0.9 |
- 2.1 bar (D) |
|
|
meat cold room |
|
|
(R134a) |
|
|
|
+0.5°/+2°C |
Meat cold room with |
12K |
0.8 - 0.9 bar |
85 |
0.7 |
- 2.1 bar (D) |
|
|
natural air circulation |
|
|
(R134a) |
|
|
|
–1°/0°C |
Refrigeration meat |
14K |
0.6 bar |
85 |
0.5 |
- 1.8 bar (D) |
|
|
counter (open) |
|
|
(R134a) |
|
|
|
+2°/+6°C |
Milk cold room |
14K |
1.0 bar |
85 |
0.7 |
- 2.1 bar (D) |
|
|
|
|
|
(R134a) |
|
|
|
0°/+2°C |
Fruit cold room |
6K |
1.3 - 1.5 bar |
90 |
1.2 |
- 2.1 bar (D) |
|
|
Vegetable chiller |
|
|
(R134a) |
|
|
|
–24°C |
Freezer |
10K |
1.6 bar |
90 |
0.7 |
- 2.2 bar (S) |
|
|
|
|
|
(R404A) |
|
|
|
–30°C |
Ventilated deep |
10K |
1 bar |
90 |
0.3 |
- 2.7 bar (S) |
|
|
freeze room |
|
|
(R404A) |
|
|
|
–26°C |
Ice cream freezer |
10K |
1.4 bar |
90 |
0.5 |
- 2.0 bar (S) |
|
|
|
|
|
(R404A) |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Al0_0015
<![if ! IE]> <![endif]>controls Pressure |
© Danfoss A/S (AC-DSL/MWA), 10 - 2006 |
DKRCC.PF.000.G1.02 / 520H1459 |
23 |
Fitter notes |
Pressure controls |
||
|
|
|
|
Test of contact function |
When the electrical leads are connected and the |
|
|
|
|
||
|
system is under normal operating pressure, the |
|
|
|
contact function can be tested manually. |
|
|
|
Depending on the bellows pressure and setting, |
|
|
|
the test device must be pressed up or down. |
|
|
|
Any reset mechanism becomes inoperative |
|
|
|
during the test. |
|
|
|
On single units: |
|
|
|
Use the test device at top left. |
|
|
|
On dual units: |
|
|
|
Use the test device on the left for low-pressure |
|
|
|
testing and the one at bottom right for high- |
|
|
|
pressure testing. |
|
|
|
|
Al0_0018 |
|
|
Warning! |
|
|
|
|
|
|
|
The contact function on a KP |
|
|
|
Pressure Control must never be |
|
|
|
tested by activating the device at top |
|
|
|
right. If this warning is ignored, the control may |
|
|
|
go out of adjustment. In the worst case function |
|
|
|
can be impaired. |
|
|
|
|
|
|
Al0_0019
On the KP 15 dual pressure control with optional automatic or manual reset on low-pressure
and high-pressure side, automatic reset must be set when servicing is being carried out. The pressure control can then automatically restart. Remember, the original reset function must be set after servicing.
The pressure control can be protected against being set on automatic reset: Simply remove the washer controlling the reset function!
If the unit is to be protected against tampering, the washer can be sealed with red lacquer.
Al0_0020
|
|
|
|
|
Low pressure |
Manual reset *) |
Automatic reset |
Automatic reset |
Manual reset |
|
|
|
|
|
High pressure |
Manual reset *) |
Manual reset |
Automatic reset |
Automatic reset |
|
|
|
|
|
*) Factory setting |
|
|
|
Al0_0021 |
24 |
DKRCC.PF.000.G1.02 / 520H1459 |
© Danfoss A/S (AC-DSL/MWA), 10 - 2006 |
Fitter notes |
Pressure controls |
||
|
|
|
|
The correct pressure control |
KP with solder connections can be used instead |
|
|
|
|
||
for your system |
of flare connections on hermetic systems. |
|
|
|
|
|
|
Al0_0006
In ammonia plant where KP pressure controls are used, they must be type KP-A.
A connector with M10 × 0.75 – 1/4 - 18 NPT (code no. 060014166).
Al0_0002
For refrigerating systems containing a large quantity of charge medium and where extra safety is desired/demanded (Fail-safe): Use KP 7/17 with double bellows. The system will stop if one of the bellows ruptures - without loss of charge.
Al0_0003
For systems operating with low pressure on the evaporator side, and where the pressure control must regulate (not just monitor): Use KP 2 with a small differential.
An example where pressure control and thermostat are in series:
KP 61 regulates the temperature via compressor stop/start.
KP 2 stops the compressor when suction pressure becomes too low.
KP 61: |
|
|
CUT IN |
= |
5°C (2.6 bar) |
CUT OUT |
= |
1°C (2.2 bar) |
KP 2 low pressure: |
||
CUT IN |
= |
2.3 bar |
CUT OUT |
= |
1.8 bar |
Al0_0004
<![if ! IE]> <![endif]>controls Pressure |
© Danfoss A/S (AC-DSL/MWA), 10 - 2006 |
DKRCC.PF.000.G1.02 / 520H1459 |
25 |
Fitter notes |
Pressure controls |
|
|
The correct pressure control For systems where KP is activated occasionally for your system (cont.) (alarm) and for systems where KP is the signal source for PLC, etc.: Use KP with gold contacts;
these give good contact at low voltages.
Al0_0005
26 |
DKRCC.PF.000.G1.02 / 520H1459 |
© Danfoss A/S (AC-DSL/MWA), 10 - 2006 |
Fitters notes |
Thermostats |
|
|
Contents |
|
|
|
Page |
|
Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . |
. . . . . |
. . . . . |
. . . . . |
. |
. 29 |
KP thermostat with air sensor . . . . . . . . . . . . . . . . |
. . . . . |
. . . . . |
. . . . . |
. |
29 |
Setting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . |
. . . . . . . . . . |
. . . . . . . . . . |
. . . . . . . . . . |
. . |
. 30 |
Thermostats with automatic reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 |
|||||
Thermostats with maximum reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 |
|||||
Thermostats with minimum reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 |
|||||
Setting example . . . . . . . . . . . . . . . . . . . . . . . . |
. . . . . |
. . . . . |
. . . . . |
. |
. 31 |
Test of contact function . . . . . . . . . . . . . . . . . . . . . |
. . . . . |
. . . . . |
. . . . . |
. |
31 |
KP 98 dual thermostat . . . . . . . . . . . . . . . . . . . . |
. . . . . |
. . . . . |
. . . . . |
. |
31 |
The correct thermostat for your refrigeration system . . . . . . . |
. . . . . |
. . . . . |
. . . . . |
. |
32 |
Vapour charge . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 |
|||||
Absorption charge . . . . . . . . . . . . . . . . . . . . . |
. . . . . |
. . . . . |
. . . . . |
. |
. 32 |
Low voltage . . . . . . . . . . . . . . . . . . . . . . . . . |
. . . . . |
. . . . . |
. . . . . |
. |
32 |
Placing of surplus capillary tube . . . . . . . . . . . . . . . . . |
. . . . . |
. . . . . |
. . . . . |
. |
33 |
Thermostats with vapour charge . . . . . . . . . . . . . . . . |
. . . . . |
. . . . . . . . . . |
. |
. 33 |
|
|
|
|
|
|
<![if ! IE]> <![endif]>Thermostats |
© Danfoss A/S (AC-DSL/MWA), 10 - 2006 |
DKRCC.PF.000.G1.02 / 520H1459 |
27 |
Notes
28 |
DKRCC.PF.000.G1.02 / 520H1459 |
© Danfoss A/S (AC-DSL/MWA), 10 - 2006 |