Start-Up Inspection - Accorroni MEC MIX C Technical Information

Flame monitoring
The flame detecting device exploits the self rectifying
property of the flame. Note that, about safety, this
device is more sensitive to the flame during the purging
ventilation and the ignition steps (negative differential
switching).
Minimum ionizing current:
System's temperature probes
- Control probe (SR)
The control probe is used for heat-exchanger
temperature detection and thus for both fan control and
safety stop. It is a NTC double sensor type (standard
version) and BRAHMA ST16 sensor is required (see
picture 3).
- Room temperature probe (SA) - optional
The room temperature probe can be used in case the
remote control panel, equipped with room temperature
sensor, is placed in a separate room or the room
temperature shall be related to the outdoor one either.
See "FUNCTIONS" paragraph for more details.
To this purpose BRAHMA ST07 sensor is required for
room temperature detecting and BRAHMA SSE for
outdoor temperature.
Fire damper (STF) - optional By means of this contact
the status of the eventual fire damper can be detected,
considering it normally closed. If the contact opens the
unit's control interrupts the running cycle and keeps it
on stand-by. An alarm activates as well and it is shown
by lighting of the led.
Upon request, the response of the unit in case of
"contact open" may be changed.

4.4 START-UP INSPECTION

It is strictly recommended to perform the unit inspection
before the start-up and any time it occurs the unit hasn't
been running for a long time or periodic check-up has
been carried out. Before starting the unit check the
followings:
- the combustion chamber is free from gas
- if ignition cycle is simulated without gas, check the
unit lockout occurs after the safety time
- if gas supply is interrupted while the unit is
running, check the solenoid valve cut-off happens
within 1 s. After restarting, the unit lockout shall
occur after a certain number of cycles (see set-up
parameter)
- operation timing and sequence shall correspond to
those declared for the type of control unit used
- the flame sensor signal shall be high enough
(Fig. 4)
- the ignition electrodes shall be properly fixed to
have clearance equal to 2-4 mm
- the activation of safety devices shall cause the unit
lockout or the safety stop, in compliance
with the type of application.
5. CHRONO-THERMOSTAT GA1
0.5 μA 5.1 APPLICATION
The digital chrono-thermostat GA1canbeweekly
Programmed for remote controlling the MEC MIX and
the room temperature, allowing 3 different temperature
levels and driving one or more heaters. It doesn't
require power supply connection nor battery and it
can control 3 different heaters but they need to be
equipped with relative interfacing pcb, which shall be
specified in the order.
To the aim of a flexible management of the facility
heating, this control panel allows of different
function modes: manual control; holidays; freezing
prevention.
The heater control is included in the chrono thermostat
as well, which manages the power output and the
automatic alarm resetting.
Here below a detailed description of the chrono
thermostat function and the user guide are
reported.
Picture 5 shows the look of this unit and picture 6
shows the display of the panel and picture 7 shows
the performances.
The use of serial interface is possible by adding
BRAHMA 810 unit and dedicated software.
Connection of the probe double NTC
Measuring of the flame signal
15
Brown
Black
Blue
Mirco amper measure
Fig. 3
Fig. 4