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
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
Fitters notes Thermostats
Installation
If the risk of water droplets or water spray is
present, t a top plate. The plate increases the
grade of enclosure to IP 44 and is suitable for all
KP thermostats. The top plate must be purchased
separately (Code no.: for single unit, 060-109766;
for dual unit, 060-109866).
To obtain IP 44, cover all holes in the backplate of
the thermostat.
If the unit is to be used in dirty conditions or
where it might be exposed to heavy spray it
should be tted with a protective cap. The
cap can be used together with either an angle
bracket (060-105666) or a wall bracket (060-
105566).
Aj0_0001
Thermostats
KP thermostat with air sensor
Aj0_0002
If the unit risk being exposed to heavy water
inuence 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
Remember that the dierential is aected by
air circulation around the sensor. Insucient air
circulation can increase the dierential by 2-3°C.
Place the room thermostat so that air is able to
ow freely around the sensor. At the same time,
ensure that the sensor is not exposed to draughts
from doors or radiation from the evaporator
surface.
Never place the thermostat directly on a cold
wall; this increases the dierential. Instead,
mount the unit on an insulating plate.
Aj0_0003
© Danfoss A/S (AC-DSL/MWA), 10 - 2006 DKRCC.PF.000.G1.02 / 520H1459 29
Fitters notes Thermostats
KP thermostat with air sensor
(cont.)
Setting
Thermostats with
automatic reset
When placing the sensor: Remember that air
must be able to circulate freely around the
sensor. With control from, for example, return
air temperature, the sensor must not touch the
evaporator.
KP thermostat with cylindrical sensor
There are three ways of securing the sensor:
1) The pipe.
2) Between evaporator ns.
3) In a pocket.
Always set the highest temperature on the range
scale. Then set the dierential on the DIFF scale.
The temperature setting on the range scale
then corresponds to the temperature at which a
refrigeration compressor will be started on rising
temperature. The compressor will stop when the
temperature corresponds to the value set on the
DIFF scale.
For pre-setting of vapour charged thermostats,
the graph curves stated in the customer
instruction sheet should be used.
If the compressor will not stop when it is set for
low stop temperatures: Check to see whether
the dierential has been set at too high a value.
Ah0_0006
When using a pocket: Always use heat-conductive compound (code no. 041E0110) to ensure
good contact between sensor and medium.
Aj0_0004
Aj0_0005
Thermostats with
maximum reset
Set the highest temperature = stop temperature
on range scale.
The dierential setting is xed. When the temperature on the thermostat sensor corresponds
to the dierential setting, the system can be
restarted by pressing the "Reset" button.
Thermostats with
minimum reset
Set the lowest temperature = stop temperature
on range scale.
The dierential setting is xed.
When the temperature around the thermostat
sensor has risen to the dierential setting, the
compressor can be restarted by pressing the
“Reset” button.
Aj0_0006
30 DKRCC.PF.000.G1.02 / 520H1459 © Danfoss A/S (AC-DSL/MWA), 10 - 2006
Fitters notes Thermostats
Setting example
Test of contact function
The temperature in a deep freeze room is to be
controlled by a thermostat that closes a solenoid
valve. The system is of the pump-down type and
is stopped via a low-pressure control.
Here, the pressure control must not be set to
cut out at a pressure lower than necessary.
At the same time, it must cut in at a pressure
corresponding to the cut-in temperature of the
thermostat.
Example:
Deep freeze room with R404A
Room temperature: –20°C
Thermostat cut out temperature: –20°C
Thermostat cut in temperature: –18°C
Pressure control cut out
pressure: 0.9 bar (–32°C)
Pressure control cut in
pressure: 2.2 bar (–18°C)
Thermostats
Aj0_0007
When the electrical leads are connected, the
contact function can be tested manually.
Depending on the sensor temperature and
the thermostat setting, the test device must
be pressed up or down. Any reset mechanism
becomes inoperative during the test.
Use the test device at top left.
KP 98 dual thermostat
Aj0_0009
Warning!
The contact function on a KP
single thermostat must never
be tested by activating the
device on the righthand side. If this warning
is ignored, the thermostat might go out of
adjustment. In the worst case, function can be
impaired.
Use the test device on the lefthand side to
test function on rising oil temperature and the
test device at bottom right to test function on
rising pressure gas temperature.
Aj0_0010
© Danfoss A/S (AC-DSL/MWA), 10 - 2006 DKRCC.PF.000.G1.02 / 520H1459 31
Fitters notes Thermostats
The correct thermostat for
your refrigeration system
Vapour charge
Absorption charge
A thermostat must contain the correct charge, as
described below.
Low temperatures, coldest bellows, not enclosure-sensitive.
Thermostat with air coil: On gradual temperature
rise and fall (less than 0.2K/min), e.g. in large,
sluggish cold rooms containing many items, KP
62 with vapour charge is recommended.
High temperatures, enclosure-sensitive. Bellows
colder or warmer.
Thermostat with air coil: On fast changes in
temperature (more than 0.2K/ min), e.g. in
smaller cold rooms where the produce turnover
rate is high, KP 62 with absorption charge is
recommended.
Straight
capillary tube
60I8012
Remote air coil
60I8032
Vapour charge
Air coil
(integral with
thermostat)
60I8013
Double contact
remote bulb
60I8017
Cylindric
remote bulb
60I8008
Low voltage
For systems where KP is activated occasionally
(alarm) and for systems where KP is the signal
source for PLC, etc. (low voltage): Use KP with
gold contacts; these give good contact at low
voltages.
Absorption charge
Aj0_0012
Air coil
(integral with
thermostat)
60I8013
Remote air coil
(for duct mounting)
60I8018
32 DKRCC.PF.000.G1.02 / 520H1459 © Danfoss A/S (AC-DSL/MWA), 10 - 2006
Fitters notes Thermostats
Placing of surplus
capillary tube
Thermostats with
vapour charge
Dual thermostat KP 98:
Surplus capillary tube can fracture if vibration
occurs and might lead to loss of thermostat
charge. It is therefore very important that the
following rules be observed:
When mounting direct on compressor:
Secure the capillary tube so that the
compressor/thermostat installation vibrates as
a whole. Surplus capillary tube must be coiled
and bound.
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 thermostat to the base on which the
thermostat is mounted.
Never locate a KP thermostat with vapour charge
in a room where the temperature is or can be
lower than that in the cold room.
Aj0_0017
Thermostats
Never allow the capillary tube from a KP
thermostat to run alongside of a suction line in a
wall entry.
Aj0_0014
Aj0_0015
© Danfoss A/S (AC-DSL/MWA), 10 - 2006 DKRCC.PF.000.G1.02 / 520H1459 33
Loading...