Buderus Logamax plus GB162 Technical Manual page 55

Pos. General design information on hydraulics and control
Provide the discharge pipes from safety valves in accordance with DIN-EN 12828 so that any expelled heating
water can be drained off safely. This requirement is met, because with the Logamax plus GB162-15/25/35/45 gas
condensing boilers, the discharge pipe of the integral safety valve terminates in the appliance siphon.
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For the Logamax plus GB162-50/65/80/100 appliances, the safety valve is part of the pump assembly. Where no
pump assembly is used, provide appliance protection on site. The required drain outlet with siphon is available as a
connection accessory.
Check the sizing of the diaphragm expansion vessel in accordance with DIN 4807-2 and DIN-EN 12828. Install a
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suitably sized expansion vessel on site.
The maximum transferable output of the Logamax plus GB162 with an underfloor heating system directly
downstream is limited. When transferring greater outputs, allow for a low loss header with flow temperature
10 sensor. Underfloor heating systems with pipes that are permeable to oxygen require system separation.
Weather-compensated control is recommended in conjunction with underfloor heating systems due to the inertia
during heat-up.
For open flue operation of the Logamax plus GB162 gas condensing boiler, the IP rating is IP 40. For balanced
flue operation of the Logamax plus GB162, the IP rating is IP X4 D. The Logamax plus GB162 is equipped with a
plug-in strip that includes a suitable plug for the power cable. A further connection is provided in the cable harness
that provides an output for supplying power to a function module of the Logamatic EMS control system, which can
be sited inside the gas condensing boiler. A pre-assembled terminal and a matching slot for the mains output is
part of every function module; this is suitable for supplying an additional function module inside the appliance with
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mains power. The connection from the mains output to the wall mounted function module or within the relevant
pipe assembly must be provided on site.
The mains supply must be 230 V AC, 50 Hz. Install an isolator in the power cable (MCB 10 A, type B with at least
3 mm contact separation). The power supply must only be made by an authorised electrician. For electrical
installations, observe all relevant local and national regulations plus those specified by your local power supply
utility.
Alongside standard operation via the Logamatic BC10 base controller, the Logamatic EMS control system
requires an RC25 or RC35 programming unit. The flexibility of the Logamatic EMS control system enables the
arrangement of the RC35 programming unit either on the wall in the living space or in the gas condensing boiler
itself. If the RC35 programming unit is clipped into the appliance, an additional RC25 programming unit can be
12 used as a remote control. Only one RC35 programming unit can be used per system. It can be allocated to any
heating circuit. As a remote control for another heating circuit (only feasible with the RC35 programming unit in
conjunction with the MM10 mixer module and WM10 low loss header module), a further RC25 programming unit
can be installed in the living space of the second heating circuit. One RC25 programming unit can be used per
heating circuit, i.e. not more than two per system.
The RC35 programming unit can control further control components in conjunction with the additional function
modules. The flexibility of the Logamatic EMS control system enables the installation of the function modules either
in the appliance itself (two slots) or on the wall near the relevant pipe assembly. For more complex hydraulic
systems, use the Logamatic 4121 control unit. Primarily, this applies to the following:
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• Systems with more than one heating circuit with mixer
• Systems with solar central heating backup
• Systems with a primary system
• Cascade systems
The Logamax plus GB162-45/50/65/80/100 appliances are equipped with an integral 3-way diverter valve.
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The 3-way diverter valve is available as an accessory and must be installed on site.
Protect the 40 l stratification cylinder of the GB162-25 T40S in accordance with DIN 1988/EN 1717.
15 The cylinder has a maximum operating pressure of 10 bar. The safety assembly that is available from the factory is
equipped with an 8 bar safety valve, a cold water shut-off valve and a non-return valve.
Table 22 Information regarding the sample circuit diagrams (
the Logamax plus GB162
6 720 645 821 (2010/09) – Logamax plus GB162
fig. 46 and fig. 47, page 53) for all systems that include
System examples 6
Further
information
Page 22 f.
Pages 27 ff.
Pages 87 ff.
Page 65 f.
Page 58
Pages 70 ff.
Pages 73 f.
Pages 39 ff.
Pages 70 ff.
Page 31
Pages 34 ff.
Page 42
Pages 70 ff.
Page 31
Pages 37 ff.
Pages 70 ff.
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