Nu-Way PO160, Installation & Maintenance Manual

Page: 20 / 56

Page C.5
PO Series Technical Specification
Oil Nozzle
The oil nozzle is of the spill-back type and is fitted
to the front end of the inner assembly and located
in the flame tube. Page C.6.
The primary function of the nozzle is to spray oil
in a suitable pattern into the combustion air stream
at a rate appropriate to the appliance’s thermal
rating.
Oil Solenoid Valve (tip shut-off)
This valve operates the needle that releases oil to
the burner tip.
Non-return Valve
This valve allows flow in one direction only.
Control Panel
The control panel is a separate unit, free-standing
or wall-mounted, that is positioned adjacent to the
burner unit. The panel design depends upon
whether the boiler is for water heating or steam
raising. The sequence controller, relays, indicating
lamps, panel isolating switch etc. are contained
within this unit.
The burner is also fitted with an ignitor/terminal
box on the side of the burner casing. This is a
junction for all electrical components that are held
in the free standing control panel.
Connections must be made between the control
panel and the terminal box.
Flame Monitor
All P Series burners are fitted with continuous flame
supervision systems employing a photo electric cell
to detect the presence of a flame.
B BB
BB
URNER URNER URNER URNER URNER
O O
O O
O
PERA PERA PERA PERA PERATING TING TING TING TING
S S
S S
S
EQUENCE EQUENCE EQUENCE EQUENCE EQUENCE
The operating sequence of P Series Burners begins
with checks on external interlocks and a check for
no flame, a pre-purge period on full air is then
initiated.
On completion of the pre-purge period the
appropriate oil valve or valves open, ignition is
initiated and low fire is established then the burner
modulates to high fire.
The burner sequence controller will then continue
to its normal operating position (i.e. it continues
to supervise the control functions and is therefore
able to shutdown the burner safely should this be
necessary), after driving to high fire, the modulating
controller will drive the burner towards the low
flame position, but, depending on the temperature/
pressure, will stop in any intermediate position
between low and high flame.the burner will be
controlled by the modulation controller.
Burner Sequence Controller
The burner sequence controller, together with the
flame monitoring system, provide a safe light-up
sequence for the burner.
A Landis & Staefa burner controller of the type
LAL2.25 (see the diagram Burner Sequence
Controller : Landis & Staefa LAL2.25 on Page C.14)
is fitted as standard.
RWF40 M RWF40 M
RWF40 M RWF40 M
RWF40 M
ODUL ODUL ODUL ODUL ODULA AA AATING TING TING TING TING
C C
C C
C
ONTROL ONTROL ONTROL ONTROL ONTROL
Operation
The burner employs a modulation system using a
Landis & Staefa RWF40 Universal Controller
(shown on Page C.17).
The modulating unit drives a reversible motor
that is coupled directly to the combustion air
damper linkage. When the RWF40 determines
that a change to the burner output is required,
the air damper and the oil spill back regulating
valve are adjusted accordinly.
Basic display
The diagram on Page C.17 shows the RWF40 after
switching on the supply voltage. This condition is
called the basic display. The actual operating value
and the currently active set-point will be shown.
Manual operation, self-optimization, the operating
parameter and the configuration levels can be
activated from this display.
To change the working set point.
The basic display shows the actual pressure/
temperature of the boiler in red and the required
set point pressure/temperature beneath in smaller
green digits.
One quick press of the PGM button, the display
changes to show the set point as the larger red
digits and the SPI in the lower small green digits.