DORCHESTER DR-SA 16, Инструкция по установке, наладке и обслуживанию

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Figure 2 - Top view of the heater
A) Hot water outlet
B) Cold water inlet
1) Electrical connection
2) ON/OFF switch
3) Ignition controller reset button
4) Control thermostat knob
5) Safety thermostat reset button.
1.2 Technical description
1.2.1 Gas control valve
The water heater is equipped with a gas control valve
c/w burner control that regulates the flow of gas to the
burner. To improve ignition the opening mechanism of
the gas control valve is fitted with a delay (softlite). The
gas control valve is suitable for gases of the second and
third family. The maximum inlet pressure is 60 mbar. The
pilot system has an automatic spark ignition that make
sure that the burner ignites consistently when there is a
demand for hot water.
1.2.2 Control panel
The temperature control for the water heater is housed
in the control panel (See figure 2). For safety reasons,
heaters are fitted with two thermostats: a control
thermostat is adjustable between 40°C and 80°C and a
safety thermostat is pre-set to 90°C. The control panel
is also fitted with an ON/OFF switch (I/0). At setting “I”,
the gas control is activated on the basis of heat demand
from the control thermostat. At setting “0” the heater is
switched off.
1.2.3 Operation of the water heater
Normal operation
When there is a demand for heat a waiting period
of about 1 second elapses before the built-in spark
generator and pilot gas valve are switched on. The
ignition spark lights the pilot burner and the flame probe
detects the resulting flame. Almost immediately after the
pilot flame is detected, sparking stops and the main gas
valve is opened. The pilot flame lights the main burner.
The unit is now in operation. When the water in the unit
reaches the set temperature the thermostat switches the
burner off.
Ignition failure
If the flame is not established within the safety period of
25 seconds the automatic ignition controller locks out.
The lamp on the reset button in the control panel shows a
lockout when lit. Pushing the reset button must manually
reset the heater. If the flame is lost during normal run, the
automatic ignition controller repeats the start sequence.
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