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15756_r02
44 ซ.บรมราชชนนี 70 ถ.บรมราชชนนี ศาลาธรรมสพน์ ทวีวัฒนา กทม. 10170.
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A ventilated installation environment and a suitably low
temperature ensure the longest life of the control system.
Before installing or replacing the unit, make sure that the type,
code and times are correct.
The control systems specified as IP00 should be installed in
appliances providing adequate protection against the risk of
electric shock (at least IP20).
ELECTRICAL INSTALLATION
Respect the applicable national and European standards
regarding electrical safety (e.g. EN 60335- 1/EN 50165).
Connect
live
and
neutral
correctly. The non-observance of
live-neutral
polarity may cause a dangerous situation, as
internal and external protection and safety devices may
become ineffective in case the connection cables of the
thermostats and the valves should lose their insulation.
Besides, the non-observance of
live- neutral
polarity causes
lockout at the end of the safety time at start-up.
Before starting the system check the cables carefully. A wrong
wiring can damage the unit and compromise the safety of the
appliance.
Make sure that the
earth
terminal of the control system, the
metal frame of the burner and the
earth
of the mains supply are
well connected.
Avoid placing the detection cable close to power or ignition
cables.
Use heat resistant detection cables and electrodes, and make
sure that they are well insulated to
earth
and protected from
possible moisture or water in general.
Keep the ignition cable as short and straight as possible and
place it far from other conductors to reduce the emission of
electromagnetic interference (max length
<2m and insulation voltage >25kV).
In case of a
live-neutral
network with
unearthed neutral
or a
live-
live
network (with
unearthed
star centre), the control unit can
operate as well thanks to an inbuilt resistor; however, in these
cases we recommend using our step-up transformer type AR1.
In case of bad insulation between
live
and
earth
, the voltage on
the ionization probe can be reduced until it causes the lockout of
the control unit.
CHECKING AT START-UP
Check the control system before the first start-up, after any
overhaul and after a long period of non-operation. Before any
ignition attempt make sure that the combustion chamber is free
from gas, then check the following:
if the start-up attempt occurs without gas supply, the control
system should go to lockout at the end of the safety time;
when stopping the gas flow while the control system is running,
the power supply to the gas valve(s) should be interrupted
within 1s, and the control system should proceed to lockout
after a recycling attempt;
operating times and sequence should correspond to those
declared for the type of control unit you are using;
the level of the flame signal should be high enough (see Fig.6
for the measuring method to adopt);
the ignition probe should be adjusted in the most stable way for
a spark gap between 2-4 mm;
the intervention of limiters or protection devices should cause a
safety shutdown according to the type of application.
OPERATION
At every start-up the control system performs a self- checking of
its own efficiency. During the waiting or pre- purge time (TW) the
internal circuit tests the correct operation of the flame signal
amplifier. Extraneous light or a
fault in the amplifier leading to flame simulation prevent the control
system from starting.
In the types with fan control, before the beginning of the pre-purge
time the air pressure switch contacts are checked to prove their
"no-air-flow" condition. If this test is positive, the air pressure
switch detects the air flow and consequently switches to "air-flow"
position, allowing in this way the pre-purge time to begin.
At the end of the waiting or pre-purge time, the gas valve is
energized and the ignition device is operated. In this way the
safety time (TS) begins.
If a flame signal is detected during the safety time, the ignition
device is disabled and, in some models, the independent auxiliary
contact (SM191N) or the main valve control switch from "off" to
"flame-on" position.
Else, if no flame signal is detected during the safety time, at the end
of the same the control system goes to lockout, the gas valve is
closed, the ignition device disabled and the lockout signal
energized.
Flame failure during the safety time causes the ignition device to be
re-activated within one second.
Please see the attached operating cycle diagrams to better
understand the operation of each control unit.
RESETTING THE CONTROL UNIT
In case of lockout, wait at least 10 seconds before trying to reset
the unit; if this time is not observed, the system may not reset
correctly. In general, the reset push-button should be visible and
placed near the appliance. Reset can only occur by an intentional
manual operation and not by means of any automatic devices such
as thermostats or timers.
In the appliance it is possible to combine the reset push- button
with the main switch; in this case, however, a light alarm will have
to be installed.
Fig.6
DETECTION
ELECTRODE
IGNITION
ELECTRODE