24
Remeha
Gas 3002 ECO
The input resistance at the analog input is approx. 10 k
Ω
(see also electrical wiring diagram at para. 10.9). This
signal represents the start command and the required
output of the boiler according to fig. 16.
B2. Through the RS 232 bus.
Select in the service level the option 'Input selection:
computer'. Through a PC or BMS the start/stop com-
mand and the required flow temperature are now trans-
mitted to the boiler.
Contact our technical department for more information
about RS 232 connection.
10.4.3 High/low control
It is also possible to control the boiler high/low.
The internal PI control cannot be used for high/low con-
trol. Switch off the internal control to select in the service
level the option 'Control selection: external' (see para.
7.3.3). The boiler now can operate on two volt free con-
tacts. The first step should be connected to terminal 23
and 24 and is indicated by the following symbol:
The current through the contacts is approx. 6 mA. And
the second step to 25 and 26 is indicated by the fol-
lowing symbol:
The power for this input is supplied by the boiler at a level
of 24V DC. The current through the contacts is approx. 6
mA. The terminal strip is in the boiler control panel (see
the electrical wiring diagram at para. 10.9).
10.5 Connections
10.5.1 Other inputs
General:
All inputs (with the exception of the analog input) are
powered via the boiler with a voltage of 24 V DC.
The current is approx. 6 mA per input. No connection
whatsoever may be connected in any way with the
phase, zero or earth of the mains power circuit. All con-
nections must be made with potential-free contacts.
10.5.2 Blocking inputs
The control system is equipped with two blocking inputs
which can switch off the boiler. These inputs can be
used, for example, in combination with the limit switches
of
throttling valves, minimum gas pressure switches, etc.
Blocking input 1 is fitted on terminals 29 and 30, whilst
blocking input 2 is fitted on terminals 31 and 32.
The symbol for both inputs is:
If you wish to use either input, the wire bridge must first
be removed. As long as the input is opened, the relevant
message will appear on the display until the contact is
made.
10.5.3 Locking input
The control system is equipped with one input which may
lock the boiler. These input can be used, for example, in
combination with the maximum gas pressure switch, the
locking input is fitted on terminals 33 and 34.
The symbol for the input is:
If you wish to use the input, the wire bridge must first
be removed. As long as the input is opened, the boiler
will be locked, and the relevant message will appear on
the display. Once the contact is closed, the boiler must
once again be released via the reset button.
10.5.4 Gas leak check
A gas leak check, to be supplied by Remeha, can be
connected to inputs 37 and 38. In this case, the control
must be adjusted for the presence of the gas leak check
at the service level (see para. 7.3.3, option 7).
The symbol for this input is:
