Thermona Therm 28 KD, Руководство по установке

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A repeated check of the through-flow switch is activated whenever it does not switch within 15 sec after the
pump started to operate. The pump halts and when another 45 passes, another attempt to start the boiler is made.
This is repeated ten times. If the tenth try is not succesfuls, it is necessary to switch the boiler off and switch it
on subsequently by the mode switch. If the non-operation state of the pump between the halt and the repeated
start of the boiler lasts longer than 30 min, the first operation interval of the pump is prolonged at 180 sec. The
intervals between the individual test cycles are indicated according to the following list of malfunctions.
An accredited service technician is bound to inform the user about the correct use of the boiler, about its
parts and safety elements, to fill in the letter of guaranty and to give the user this manual.
The user has to use the boiler only in the ways described in this manual. This is also the condition for
guarantee. The user is strictly forbidden to change or interfere with the fixed parts of the boiler!
8. SIT 848 SIGMA GAS FITTING
gas inlet
solenoid coils
module for measuring
the inlet gas pressure
gas outlet
setting of the air/gas ratio
air pressure signal inlet
module for measuring
the outlet gas pressure
setting of the starting point of regulation
SIT 848 SIGMA is a gas fitting with proportional regulation: air/gas. It is equipped with two solenoid valves that
prevent the penetration of gas at the time when the boiler is out of operation. The regulation system works in
correlation with the feedback signal of the gas pressure from the mixer. Apart from the lockable measuring
modules
of the inlet, outlet and medial gas pressure, there are devices that make it possible to set the correct air-gas
ratio throughout the output regulation range.
1. Starting point of the regulation – setting:
The setting is done by means of a screw that is placed at the pad of the
regulation system of the auxiliary membrane. The screw is only accessible if a
brass cover is removed.
The air-gas ratio is set at the minimum output of the boiler (i.e. at the minimum
running speed of the ventilator.) If the screw is screwed in, the proportion of
gas in the mixture gets lower.
2. The air/gas ratio – setting:
The setting is done by the regulation screw of the gas throttle placed at the
gas valve outlet.
The air-gas ratio is set at the maximum output of the boiler (i.e. at the
maximum running speed of the ventilator). If the screw is screwed in, the
proportion of gas in the mixture gets lower.
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The solenoid coil connector - wiring diagram: