Rendamax R2000 Series, Техническая документация инструкция

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26
DOC2012/2000en
Positioning the pump and expansion vessel
We advise that the pump should be mounted in the return pipe in the following order:
expansion vessel, pump, boiler.
If you mount the pump in the flow pipe, the lifespan of the pump will be reduced.
Always connect the expansion vessel to the suction side of the boiler pump.
If the boiler is installed on the roof, you should take into account the maximum permitted pressure in
radiators on the ground floor and that the flow and return connections are taken upwards from the boiler
before descending to ensure the heat exchanger is filled with water.
Pump switching
It is necessary to electrically switch the boiler in such a manner that it will never operate before the
installation and boiler pump is running. It is essential that an overrun switch is used to allow the pump
to operate for
at least 3 minutes after the burnes have turned off.
The effect of flow velocity of the installation on boiler water temperature
ALWAYS MOUNT SECONDARY MOTORIZED OR MIXING VALVES IN THE SECONDARY WATER
CIRCUIT WITH AN OPENING TIME OF AT LEAST 120 SECONDS!
Fast acting mixing valves in the secondary water circuit may give the boiler regulator insufficient time to
make proper corrections.
This may lead to an unacceptable high temperature, as a result of which the high limit thermostat
may lock-out the boiler.
Such a problem may also occur if all flow governors close simultaneously. The flow governors should
therefore close one after the other.
The sudden disconnection of an important warm air heating unit may cause the same problem.
If a large fan can be switched off immediately, you should consider switching off the boilers first
(temporarily if necessary), and subsequently the fan using a time relay.
When the flow governors are opened for night time temperature reduction for example, it is essential
that
the return water temperature of the heat exchanger does not fall below 40°C
(as condensation in the combustion chamber may occur).
If an installation is to be optimized, the primary water circuit consisting of boilers, boiler pumps and open
header should be started before the system is switched on.
Open the groups subsequently one after the other by using a return water temperature regulator for
example, adjusted to 40°C. Switch on the secondary pumps one after the other.
The primary circuit must have a low water volume. This enables faster heating and reduces the
condensing time of the boiler.
The recommended maximum volume of the primary circuit per 100 kW installed boiler capacity is
200 litres. When the installation is switched off, the boilers must be switched off first. After approximately
3 minutes the boiler pumps and the heating groups can be switched off.
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