2
Product description
Logano G315 – 6 720 817 939 (2017/02)
6
2.1
Designated use
The Logano G315 oil/gas-fired boilers have been designed for the
heating of water.
The Logano G315 can be operated with oil, gas, and combination
burners. For a list of the approved burners, please contact Bosch
Thermotechnology Corp.
This boiler can be operated with an aquastat, the Logamatic 4000, and
other control systems.
2.2
Operating conditions
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 heating 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 unique feature reduces thermal stress, the
main cause of failure of traditional cast iron boilers. The advantage of
this technology is the maintenance of the minimum operating
temperature of the boiler (
Tab. 3); this makes the installation of a
shunt pump unnecessary. This way, the costs for the pump itself and its
power consumption, as well as possible failure costs are saved. 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.
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 water
temperature. The controls can reduce the flow rate by closing the valves
on the mixed heating circuits, modulating the boiler primary pumps,
closing the motorized butterfly valves or by having a motorized valve in
the boiler return on a single boiler installation. The Buderus 4000 series
controls can manage this process or it can be completed by the BMS.
If it is not possible for the control panel 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 panel or with a third-party controller. 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.
2.3
Compliance with standards and regulations
Installation and operation of the system must comply with all applicable
codes, regulations and statutory requirements.
Installation, connection of the fuel supply and flue connector,
commissioning, connection of the electrical power supply, servicing and
repair may only be carried out by a trained or certified heating
contractor. Only registered gas fitters may carry out work on the gas
train.
The system must be cleaned and serviced once a year. The operation of
the complete system must be tested at the same time. Any faults must be
corrected immediately.
The design and mode of operation of this boiler must comply with the
American National Standard ANSI Z21.13/CSA4.9, latest edition for
Gas Fired Low Pressure Steam and Hot Water Boilers.
Other confirmed approvals and certifications are indicated by labels on
the boiler.
The heat exchanger has been designed and certified in accordance with
the ASME Boiler and Vessel Code, Section IV.
Installation of the boiler must comply with all applicable codes and
regulations imposed by the national, Federal or local authorities and
bodies. If no specific requirements are defined, in the USA, the latest
edition of the National Fuel Gas Code ANSI Z223.1/NFPA 54 applies. In
Canada, installation must comply in all respects with the latest edition of
the Installation Code for Gas Burning Appliances and Equipment, CAN/
CSA-B.149 and the applicable local regulations and requirements for
the appliance category. The relevant authorities and regulatory bodies
must be informed before installation starts.
Where required by local regulations, the system must comply with the
American Society of Mechanical Engineers Safety Code for Controls and
Safety Devices for Automatically Fired Boilers (ASME CSD-1).
The hot water distribution system must comply with all applicable codes
and regulations. When replacing an existing boiler, it is important to
check the condition of the entire hot water distribution system to ensure
safe operation.
Valves external to the boiler must be fitted with T-handles and
condensate piping must be installed in accordance with the State
Plumbing Code.
Control of all
heating zones with
Buderus 4000
External controls
(BMS) or Aquastat
control
Minimum flow rate
none
Minimum return temperature
°F
( °C)
none
Minimum operating
temperature oil boiler
1)
1) This temperature has to be reached within ten minutes of the burner starting and
has to be maintained whilst the burner is firing.
°F
( °C)
122–(50)
Minimum operating
temperature gas boilerNOT
DEFINED
°F
( °C)
122–(50)
2)
2) 65 with partial load < 60 % °C
Maximum supply temperature
°F
( °C)
212
3)
/248
4)
3) The maximum supply temperature is 212 °F (100 °C), if the boiler is operated as
hot water boiler.
4) The maximum supply temperature is 248 °F (120 °C), if the boiler is operated as
a hot water generator.
Maximum operating pressure
PSI
(bar)
87–(6)
For operation with two-stage
oil and gas burners
–
Set the partial load stage to 60 %
Time constant of the
temperature controller
sec
40
Time constant of the monitor/
limiter
sec 40
Table 3
A heating zone with a mixing valve improves
controllability and is specifically recommended for
systems with differing water temperature zones.
Summary of Contents for Logano G315
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