January 2005
55
ABB i-bus
®
EIB
ABB Powernet EIB
a)Electrothermal valve drive:
To fully open an electrothermal valve
drive takes approx. 2-3 minutes. A
shorter cycle time than 15 minutes
is therefore not advisable.
b)Floor heating:
The time constant of a floor heating
system is very high. A cycle time of
20 minutes is therefore sufficient.
c) Warm water heating:
Electrothermal drives are frequently
used here. A cycle time of 15
minutes produces very good
results.
d)Electric fan heating:
Cycle times between 10 and 15
minutes are recommended,
depending on the electric heating
and spatial conditions.
If a two-position controller is used for
heating or cooling control, it is
possible to select the hysteresis by
which the setpoint fluctuates. If e.g.
the setpoint in heating mode is 20°C
and the hysteresis is 0.5 K, the
controller switches on at 19.75°C and
switches off again at 20.25°C. The
hysteresis that is set then depends
on how quickly the heating can heat
up the room or how quickly the
cooling cools down the room as well
as how sensitive the customer is to
temperatures. The hysteresis should
not be set too low as otherwise the
valve drive continually opens and
closes. The hysteresis should
however not be set too high as the
temperature fluctuations in the room
are then relatively high.
To increase the accuracy of the
control, the parameter “Lowering of
hysteresis” is used. If this parameter
is active the hysteresis is reduced
e.g. every minute by 0.1 K, if required
until 0 K. The temperature fluctuations
are effectively reduced during the
control by the lowered hysteresis. If a
reduction should be used, it is
advisable to select a reduction that is
less than one fifth of the hysteresis.
e.g. Hysteresis 0.5 K =>
Reduction < 0.1 K/min
In certain cases (floor heating), it may
be necessary to install a fast-acting
additional system to enable you to
heat the room up quickly. If the
“Additional heating” is active, the
panel has a second heating system
available with a switching control
(1 bit) or a quasi continuous control
which regulates the heating with the 1-
byte values 0% and 100%.
With the parameters “Level distance
from the base level to the additional
level in K” and “Hysteresis (one-
sided)”, it is determined when the
additional level is switched on and
when it is switched off. If e.g. the
setpoint for the second heating level
is set at 18°C with a hysteresis at
0.5 K (one-sided), the thermostat
switches on at 18°C and switches off
at 18.5°C.
As some valve drives close at a 1-byte
value of 255 or a 1-bit value of 1 and
open at the corresponding inverted
values, the “Effective mode” can be
inverted.
The toggling between heating and
cooling is carried out automatically by
the room thermostat. If this is not
required, the “Toggle between heating
and cooling” can be carried out by an
external, central control via the 1-bit
object “Toggle heating cooling”. In this
setting, the heating or cooling
symbols are permanently visible
during the corresponding operating
mode. If an ON telegram is received
at the operating mode object, the
heating mode is switched on. If an
OFF telegram is received, the cooling
mode is switched on.
Automatic shading
To prevent the room warming up due
to sunlight, automatic shading can be
carried out by lowering one or several
blinds. The object “Shading” is used
for this purpose.
The parameter “Shading setpoint”
determines at which temperature the
blinds should be lowered.
If the temperature falls below the set
shading temperature, no commands
for lowering the blinds are sent. The
blinds could be raised at a specific
time e.g. with a central command.
Group master mode
In rooms such as large open-plan of-
fices, it can be difficult to achieve effec-
tive control throughout the room with
only one panel operating as a room
thermostat. In such cases, it is advisab-
le to divide the room into several zones
in which one room thermostat is used
per zone. So that these room thermos-
tats always use the same setpoint, the-
LEANtouch (monochrome),
SMARTtouch (monochrome, colour)
Type: 6x36/30M(-500), 6x36/100x(-500), 6x36/100CB
