Product and Functional Description
The thermal drive actuator N 605 has been specially developed
to control miniature valves with electrothermal valve drives for
AC 230 V operating voltage. It is a DIN rail mounted component
for the instabus EIB. All the cable connections are carried out
via screw terminals except for the bus cable which is plugged
in.
6 channels with semiconductor outputs are available to control
the valve drives. The outputs each have 2 output terminals
available (for N and switched L). A maximum of 4 thermal
drives may be connected in parallel to one channel (actuator
output). The outputs are monitored for short circuits and
overload. If a short circuit or overload is detected, all the
outputs are temporarily de-energized and the red LEDs are
triggered to show a circulating light. After a cooling down
period of 6 minutes, the individual outputs are switched on in
sequence to determine where the short circuit or overload has
occurred. It is reported via a special communication object
which outputs are affected. These outputs are disabled for
further operation and the associated red LEDs flash rapidly. All
the other outputs are then operated as normal. It is only
possible to reset a disabled channel by switching off the
actuator from the mains voltage.
The application program enables the actuator outputs to be
controlled via ON/OFF switching commands or via positioning
commands expressed as a percentage. The latter are
converted into switching commands with pulse width
modulation under consideration of the heating up and cooling
down periods of a thermal drive. A changed status or the
current state of an output can be queried via a separate status
object or sent automatically. The type of the output status
object is always the same as the trigger object. The behaviour
of the actuator on bus voltage failure can also be preselected
(no action, switch on, switch off, forced position).
If the program function “Calcification protection” is activated,
each actuator output is switched on and off once within a
period of 6 days to prevent the valves from being fixed in
position outside the heating respectively cooling period.
If you do not want that, in a room with several windows, the
opening of only one window will switch the room thermostat
to the building protection mode, hereby closing all heating and
cooling valves, then the program function “Constrained
Position” has to be activated. In this case, only the valve of the
respective radiator or cooling ceiling element that is located in
the immediate vicinity of the opened window is closed, except
for a set residual opening (constrained position). If a logical
connection of the “Constrained Position” object with the
“Frost alarm” or “Outside temperature” object is selected and
a frost alarm is not present or the outside temperature is >
1°C, the valve is fully closed if the “Constrained Position”
object is identical to logical 1.
There are 6 additional binary inputs available for floating signal
contacts in order to record and transmit the switching state
e.g. of the window contacts or dew point detectors.
The power supply of the actuator electronics is carried out via
an integrated power supply unit which is independent of the
EIB bus voltage. Each output in a group of three outputs
(outputs 1-3 or outputs 4-6) can be manually switched on or off
or to the 50% open position via three push buttons which are
integrated in the actuator and each have 1 red LED. The
manual switching also functions if the bus cable is not
connected or if the bus communication fails. After a long push
button action (> 2 s), the other valve group is selected. The
yellow LED indicates which of the two output groups can be
operated (continuous light = outputs 1-3, flashing light =
outputs 4-6).
Prerequisites
The user of the program must ensure that the following
requirements are met for the error-free operation of the
application program for the N 605:
-
The user must specify via a parameter whether the room
thermostat only sends switching command telegrams of
type EIS 1 to activate a valve whereby a logical 0
corresponds to the command for closing the valve and a
logical 1 corresponds to the command for opening the valve.
Otherwise, it must be defined whether the valve is triggered
via positioning commands of type EIS 6 expressed as
percentage values whereby 0% corresponds to a closed
valve and 100% to an opened valve.
-
The room thermostat must ensure that it never sends
switching or positioning commands which lead to the
simultaneous opening of the heating and cooling valves (i.e.
a switching/positioning command to open a valve may only
be sent by the thermostat if it has previously sent a
switching/positioning command to close the other valve).
-
Thermal drives of the same type from the same
manufacturer must be connected to all the outputs of the N
605. The user must indicate for each valve whether it is
closed or opened in the de-energized state.
-
If dew point detectors have been installed and are
connected to the EIB, the room thermostat must send a
“CLOSE” command (0% command) to the cooling supply
valve if a dew point alarm is present followed by an “OPEN”
command (100% command) when the dew point alarm is no
longer present and further cooling is required.
-
If the opening of a window is reported to the room
thermostat via the EIB and the program function
“Constrained Position” has not been activated, the
thermostat must switch to “Building protection mode” and
immediately send a “CLOSE” command (0% command) to
the currently opened supply valve. In the “Building
protection mode”, the room thermostat must ensure by
controlling the valves that the room temperature does not
fall below the setpoint value for frost protection respectively
does not exceed the setpoint value for heat protection.