Danfoss FEK-IF, FEK-FF Data sheet

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Data Sheet

FEK Sensors - Control of Cooling Circuit

Products

FEK-IF with integrated sensor FEK-FF with remote sensor

Ordering and Specifications

Application

The FEK sensor is installed in rooms which have
surplus heat due to internal or external heat
sources; i.e. only control of cooling circuit is
needed.

When the room temperature rises above the set
temperature the FEK sensor opens the cooling
valve.

FEK-IF as well as FEK-FF sensors can be used for
chilled ceilings, fan-coils and induction units.

Type Sensor Capillary tube Setting range Code no.
FEK-IF Integrated sensor 5 m
FEK-FF Remote sensor 2 + 2 m 013G5464

Control of cooling circuit - chilled ceiling

For cooling circuits in fan-coils and induction
units use the FEK-FF with remote sensor.

The remote sensor can e.g. be placed below the
cabinet of the air inlet or on a separate wall
surface.

By placing the sensor in the air inlet a quicker
reaction time of the air temperature changes is
achieved.

17-27 °C

013G5465

1. FEK-IF

2. RA-C

3. Cooling circuit

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Data Sheet FEK Sensors - Control of Cooling Circuit

Control of cooling circuit - fancoils and inductions units

FEK Sensor Design

1. FEK-FF

2. RA-C

3. Cooling circuit

1. Cooling adapter

2. Remote temperature adjuster

3. Actuator

4. Remote sensor (only FEK-FF)

Temperature Setting

The FEK sensors are applied with RA-C valves.

The FEK sensors are equipped with a reverse
device for the control of cooling circuits.

Comfort temperature ~ 22 °C at Xp = 0 K

The FEK sensors have been developed for room
cooling via water-based cooling systems.

With the reverse device the valve in the cooling
circuit will open when the temperature rises
above the set temperature.

The FEK sensors are based on the self-acting
principle. The liquid-filled sensors control the
valves via capillaries and adapters.

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Data Sheet FEK Sensors - Control of Cooling Circuit

The scale shows the approximate set-point offset
from the comfort temperature which is
approximately 22° C at Xp = 0 K.

Temperature Control
Through Cooling with FEK
Sensor

Control area of FEK sensor with RA-C valve

Xp = 0 K

Xp = 3 K

A setting in the blue temperature area means
that the setpoint of the cooling circuit is placed
below the comfort temperature, i.e. the valve will
open at a lower temperature than the comfort
temperature of appoximately 22 °C.

With a setting in the red temperature area the
setpoint of the cooling circuit is placed above the
comfort temperature. The valve in the cooling
circuit will open at a room temperature above
the comfort temperature of approximately 22 °C.

1. Waterflow cooling

2. Setpoint on knob

Limiting the Set
Temperature of FEK Sensors

Example

The knob is turned to lower the comfort
temperature with 4 °C from 22 °C to approx. 18 °C
at Xp = 0 K.

As the set point temperature is at Xp = 0 K the
valve in the cooling circuit will not open before

the sensor temperature exceeds 18 °C.

In the presetting N the RA-C valve works with a P­band of maximum 3 K. This means that the RA-C
valve will be fully open and give maximum flow
to the cooling circuit at a sensor temperature of
approx. 21 °C (set point: 18 °C + P-band: 3 K).

1. Waterflow, cooling RA-C valve with
presetting N

The set temperature of the remote temperature
adjuster depends on the sensor type and the
valves, which are used with the sensors.

It is easy to limit or lock the set temperature by
means of the built-in locking/limiting device.

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