Operating Conditions For Buderus G And Ge Cast Iron Boilers - Buderus Logano GE315 Installation And Maintenance Instructions Manual

2 System start-up
3.6

Operating conditions for Buderus G and GE cast iron boilers

Thermostream technology is a unique feature of Buderus cast iron boilers. Return water is preheated and mixed within
the boiler before it comes in contact with the heated surface of the combustion chamber. The Thermostream technology
ensures there is an even temperature distribution in the boiler and avoids condensate forming within the combustion
chamber. This reduces thermal stress, the main cause of failure of normal cast iron boilers. The benefit of this
technology is that if the minimum boiler operating temperature of the boiler is maintained (see table below), there is no
need for a conventional shunt pump to be installed, saving the cost of a pump, the electricity it consumes and the
breakdown it can cause. The minimum boiler operating temperature as shown in the table below must be reached
within 10 minutes and then be maintained while the burner is running.
3.7 Operating conditions GE 315
Logano
In conjunction
with a
GE315 Logamatic
control
2)
device
In conjunction
with a
Logamatic
control device
GE315 for constant
boiler water
temperatures,
e.g. Logamatic
4212
Tab. 3
21/2 Operating conditions for Logano GE315
1) A heating circuit control with mixer improves the control characteristics, and is recommended, in particular, in systems with several heating
circuit.
2) If heating circuits or a boiler circuit actuator cannot be regulated via the control device (for example pump logic), an operating temperature
of 50 °C must be reached within 10 min of switching the bumer ON by restricting the colume flow.
3) Modulation for gas combustion < 60% partial load, min. boiler water temperatur 65 °C.
This operating condition can be easily achieved by the controls monitoring the boiler temperature and reducing the flow
rate through the boiler until the required temperature is reached. This is then maintained by continuing to control flow
based on the boiler temperature. The controls can reduce the flow rate by closing the valves on the mixed heating
circuits or by modulating the boiler primary pumps or by closing the motorised butterfly valves or by having a motorised
valve in the boiler return on a single boiler installation. The Buderus 4000 series controls can manage this process or
it can be done by the BMS.
If it is not possible for the controls to regulate the flow sufficiently to meet this operating condition then a shunt pump
circuit must be fitted to avoid the type of thermal stress that all boilers would experience in these conditions. This shunt
pump circuit can be controlled either with a Buderus 4000 control or with a Buderus 4212 fitted with a ZM427 module.
Failure to ensure that the operating condition is maintained may lead to thermal stress in the boiler and eventual failure
of the sections which would be outside the scope of the warranty.
38
Min. boiler
Min. boiler water
water volume
temperature
flow
Not obligatory
Operating
Not obligatory
temperatures are
safeguarded by
the Logamatic
control device
Not obligatory 55 °C
Logano GE315 - We reserve the right to make any changes due to technical modifications
Operating conditions (Guarantee conditions!)
Operating
Interruption
(complete boiler
shut-down)
Not obligatory
Possible if, after
Interruption of
the operation,
2)
there follows at
least
3 hrs. heating
operation
Minimum return
temperature
For operation with two-
stage oil and gas
pressure jet bumers:
Not obligatory
Set the partial load
stage to 60%
For operation with two-
stage oil and gas
pressure jet bumers:
Not obligatory
Set the partial load
stage to 60%
Others