Alarko ACK2, Operation Manual

Page: 17 / 42

Heating system shall be equipped with safety arrangements against, exceeding
the maximum operating temperature and exceeding the maximum operating
pressure. Safety arrangements shall be designed in accordance with the type of
heating system, energy source, and the way which the heat supply is provided to
the heating system, i.e. automatically controlled or manually operated. Minimum
required safety arrangement is under the responsibility of the installer and must
be according to local codes and/or EN 12828.
MINIMUM SAFETY EQUIPMENT REQUIRED FOR SEALED SYTEMS
Protection against exceeding the maximum operating temperature : Each
boiler shall be served by a safety temperature limiter (manual reset thermostat)
including a specific sensor and the boiler temperature shall not rise by more then
10 K after switching off the heating or fuel supply line. The temperature limiter
shall confirm current EN 60730-2-9 or have CE mark. If one of the boiler control
panel is purchased (optional) then this item is present on all kinds of boiler control
panels.
Protection against exceeding the maximum operating pressure: Each boiler
shall be served by at least one safety valve in order to protect the system against
exceeding the maximum operating pressure. The safety valve is not a standard
supply with the boiler, it must be fitted by the installer on the flow line of the boiler
without any isolation valve or similar items and they must confirm prEN 1268-1
with a minimum size of DN 15.They must open at a pressure not exceeding the
maximum design pressure of the system and shall be designed to prevent the
maximum operating pressure from being exceeded by more then 10 %. Safety
valves shall be installed so that the pressure drop on the inlet pipe does not
exceed 3 % and the pressure drop of the discharge pipe does not exceed 10 %
of the safety valve set pressure.
Safety valves shall discharge safely and boilers greater then 300 kW nominal
heat output have special requirements, please refer to EN 12828.
Each boiler greater then 300 kW nominal heat output shall be served by a pressure
limiter. This is not a standard supply with the boiler; it must be fitted by the
installer on the flow line of the boiler without any isolation valve or similar items.
If the operating pressure of the heating system exceeds the given pressure limit,
the pressure limiter shall shut-off the heating or fuel supply and interlock it against
automatic restoring. Pressure limiter shall be adjusted so that it responds before
the safety valve(s) operate.
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SAFETY ARRANGEMENTS