Temperature Control - Helios WHS HE Manuel

Installation and Operating Instructions
Temperature Control System WHS HE
3.1

Temperature control

The WHS control system controls the flow temperature to the warm water heater battery with the help of a three point-
valve-actuator. It is controlled by a pulse/break signal in proportion to the control deviation. If the temperature being
controlled approaches the preset setpoint, then the run time of the actuator will reduce and the break time will increase
accordingly.
Three control functions are possible for the temperature control:
1. Constant supply air temperature control with a duct temperature sensor (TFK)
2. Constant room temperature control with an external room temperature sensor (TFR)
3. Constant room temperature control with a minimum supply air temperature limit.
With external room temperature sensor (TFR) and additional duct temperature sensor (TFK).
All three control circuits have an anti-freeze temperature sensor (TFK) behind the WHR
(see wiring diagram SS-953 and system diagram on page 2, Fig.1).
Settings for the three control functions on the control unit
Setpoint Œ MIN Ž
1. Constant supply air temperature control
0 ... 30 °C no function
2. Constant room temperature control
0 ... 30 °C no function
external
3. Constant room temperature control with a minimum supply air temperature limit (see example)
T T
>
set
external
T T
set
<
external
CF setting
Temperatur e differences
between
T and T
set min
10 K
(normal case)
Temperatur e differences
between
³ 10 K
T and T
set min
Standard setting examples for T
20
25
25
30
30
CF 
1
1
min
see table
below
min
CF values
2 – 10
5 – 15
/ T and CF
set min
10 approx. 5
15 approx . 5-10
20 approx . 2-10
15 approx . 10-15
20 approx . 5-10
11
Other
The supply air temp. is set on the electro. control unit
(WHSE) – note DIP switch position!
The room temperature is set on the external room tempera-
ture sensor (TFR) – note DIP switch position!
The setpoint should be greater than the minimum supp-
ly air temperature (normal operation)
The setpoint is less the than the minimum supply air
temperature (e.g. for reduction at weekend or at night,
the minimum supply air temperature T
short of).
The CF value determines the level of the supply air tem-
perature change, i.e. for a room temperature difference
with respect to a preset setpoint, the temperature diffe-
rence multiplied by the CF value determines the supply
air temperature; e.g. 23 °C room temperature, 25 °C
setpoint, minimum supply air temperature 20 °C and CF
3; the supply air temperature will then be increased by
6 °C (25 °C setpoint – 23 °C room value × CF 3 = 6 °C
temperature change in the supply air).
The greater the CF value, the higher the change of sup-
ply air temperature and thus also the temporal reaction
until the preset setpoint is set.
The room size, the specific heat of the room and the air
exchange must be considered when setting the CF va-
lue. Thus, large rooms and halls with frequent air
exchange require a greater CF value than small enclo-
sed spaces with low air exchange. The quicker the con-
troller (heating) should react to disturbances e.g. open
hall doors, doors and windows, the greater the CF va-
lue should be set. For small rooms or rooms with higher
specific heat (e.g. due to machines or sun exposure),
lower CF values should be set. In this respect, there is
often the problem of both warming up supply air and
cooling the room. It is then advisable to reduce the T
value and set the CF value to approximately 2-5. Minor
deviations from the set temperature are possible. The
controller accuracy is approximately ± 1 K.
For industrial halls (with poor air circulation)
For industrial buildings
For special applications e.g. dry halls
UK
is not fallen
min
min