Herz pelletstar 10, Operating Instructions Manual

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4 Equipment funtioning
12 Betriebsanleitung_PS_10_60_Touch_Englisch_V1.3
4.8 Operating temperatures and
impermissible temperatures
4.8.1 Boiler temperature
The HERZ pelletstar boiler is operated at a boiler
temperature between 65 und 90°C. If the return
flow temperature is below 55°C some of the flue
gases condense on the inside of the boiler. When
the boiler is started up, the operating temperature
(from 65 to 90°C) must therefore be reached as
quickly as possible in order to avoid condensation.
The return flow temperature may also be under
the permissible value at correct boiler operating
temperature. This condition should be avoided by
a functioning increase in return flow temperature
(at least 55°C, or preferably 60°C).
Note!
All guarantee or warranty claims are invalidated in
the event of damage from corrosion arising due to
impermissible operation temperatures.
4.8.2 Return flow temperature
The return flow temperature must increase to over
55°C (60°C) as quickly as possible, depending
upon the type of boiler. Retention of the
temperature level for the return flow or the boiler
temperature is achieved using a so-called return
flow
bypass or return flow temperature
maintenance. In this the advance flow water, for
example, is admixed via a pump and the
appropriate valve.
The heat energy of the boiler can only be used
from the time that the return flow temperature has
exceeded 60°C.
4.8.3 Boiler temperatures that are too
high
The HERZ pelletstar boiler can be operated up to
a maximum boiler temperature of 90°. If the
performance of the boiler is suddenly reduced
(mixers shut off, hot water tank load pump
switches off) it is sometimes the case that the
saved heat energy in the boiler heats up the
heating water above this value.
In the pelletstar equipment there are three safety
measures installed in order to prohibit a further
increase in temperature:

Excess temperature outlet (above 92°C boiler
temperature)
From this temperature the consumer pump is
switched on in order to divert the excess heat
energy. To do this, the loads are set to their
maximum value. The precondition for this is
that these are controlled using HERZ
controls. Should this not be the case then
there is a greater probability that the boiler
will overheat and result in a breakdown.

Thermal flow protection
No thermal overload safety device is required
for the PS 10, 20 and 30 systems. Pelletstar
45-60 systems have a safety heat exchanger
installed in the boiler to which a thermal
overload safety device must be connected.

Safety temperature limiter
– STL (above
95°C boiler temperature)
The equipment is switched off above this
temperature. The safety temperature limiter
locks itself and the equipment operation. A
breakdown is indicated and the equipment
stops.
4.8.4 Flue gas temperature
The flue gas temperature depends upon the
operating condition of the equipment, the fuel, the
ventilator setting and the type of boiler.
Therefore applies:
The chimney must not be sensitive to moisture
and must be calculated and dimensioned
according to DIN 4705 or EN 13384. HERZ does
not
carry out chimney calculations. This
calculation must be carried out by an authorised
specialist company. A chimney that is incorrectly
designed may lead to malfunction of the
equipment.