Strebel S-CB Px 120, Руководство по установке, эксплуатации и техническому обслуживанию

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S-CB Px 120 Manual 18
6.3. Flow and return connections
In the picture, an example is shown of the installation
of the flow and return connections in combination with
several functional and/or safety components. The pic-
ture does not necessarily contain ALL safety compo-
nents that may or must be applied
→
always have the
installation carried out by a skilled installer according to
all applicable standards and regulations.
It is advised to install two service valves underneath
the boiler, so the boiler can be isolated from the heat-
ing system, when needed. The valves must be posi-
tioned in such a way that no safety components like
pressure relief valves and expansion vessels can be
isolated from the boiler.
The boiler pump should always be mounted in the re-
turn pipe of the boiler.
When using a system pump, this pump should always
be mounted in the return pipe of the heating system.
Never use chlorine-based fluxes for soldering any
pipes of the water system.
NOTICE: Accessories in the picture are NOT supplied
with the boiler.
6.4. The expansion vessel
A properly selected expansion vessel must be mounted according to all applicable standards an regulation.
6.5. Pressure relief valve
The boiler has no internal pressure relief valve. This should be installed in the flow pipe of the heating system and
close to the boiler. When having cascaded boilers, each boiler should have its own pressure relief valve. It is ad-
vised to use a T-piece for this.
Advise is always to install service valves, so the boiler can be isolated from the heating system, when needed.
Make sure that the pressure relief valve is mounted between the boiler and the service valves.
The pressure relief valve must always be installed in such a way that it cannot be isolated from the boiler by a
valve. The specifications and size of the relief valve should be determined by the installer and must comply with
all applicable regulations and boiler capacity.
6.6. Bypass
The boiler has no internal bypass. When many thermostatic valves are being used, the system should have a
bypass to allow an adequate flow when all thermostatic valves are closed. Instead of a bypass also a low-loss
header can be used for this function.
The boiler flow will also be influenced when a pipe of the heating system is frozen/blocked. Make sure all hea-ting
pipes are free from the risk of frost. If there is the risk of freezing of the heating system, all the pipe sections must
be insulated and/or protected with the help of a tracing.
6.7. Pump functionality
High efficiency pump (default settings)
The pump is controlled by a PWM signal from the burner controller. Its set point is based on a delta T of 20°C.
This means, that when the burner is on full load, delta T = 20°C, and when the burner modulates down, the pump
also modulates down keeping delta T 20°C (provided it is still in range of the lowest limit of the pump).
•
The external pump must be mounted in the return pipe of the boiler.
•
The boiler pump must be controlled by the S-CB Px 20 boiler control. If, for any reason, an exter-
nal pump control is applied without written approval of Strebel Ltd , the complete warranty on the
S-CB Px 120 boiler and all supplied parts will become invalid.
flow return
BOILER
NOT
supplied
with boiler
NOT
supplied
with boiler
boiler bleed
valve for
service
pressure
relief
valve
boiler
service valves
expansion
vessel