26
Hoval STU Wood Pellet Boiler
In addition to the stoker control panel (see below) a boiler flow temperature gauge is fitted at the front of the boiler.
Control Details and Safety Features
• The stoker control panel consists of:
•
Mains Isolator (not shown above)
•
LRP control unit and Display. Slave LRP Control unit
(for boilers fitted with the optional electric ignition system).
•
Wood burner selector switch with settings ID Fan Only
/Off/Auto
•
Wood burner shutdown selector switch with settings
Burnout/Normal
•
Optional ignition selector switch with settings Auto /
Ignition
•
Optional pick-up auger selector switch
(where specified)
• The Mains Isolator will:
•
Electrically isolate the stoker and pick-up auger(s)
•
The isolator is provided with a lock-off facility.
• The LRP controller and display
has a wide variety of
settings available for fine control of the wood pellet-burning
stoker. In normal operation only a few of these may be
required to be displayed but they can be altered at the time
of commissioning to suit the site conditions. The following
are the most common parameters available for display:
IMPORTANT - 3 Phase 32A 400V supply is required for stoker and control panel operation.
•
Boiler Flow set point.
•
Wood pellet feed speed.
•
Oxygen set point.
• The stoker ID Fan Only/Off/Auto switch will:
•
Turn the stoker off when in the off position.
•
In the Auto position the stoker will be under control of
the LRP and time clock or the Building Management
System and will modulate to follow the load accordingly
and may kindle if the set point water temperature is
satisfied (includes frost protection).
•
Select the ID Fan Only position prior to opening the
boiler door
• The Burnout/Normal switch will:
•
Normally be in the Normal position.
•
In the burnout position, the conveyor auger tube will be
run out of fuel and the fire allowed to burn itself out.
• The Auto/Ignition switch (where fitted) will:
•
Normally be in the Auto position.
•
In the Ignition position the retort will be primed (from
empty) with pellets and the ignition process started.
LRP Control unit and
display screen
Selector switches
Slave LRP control unit
(only for boilers fitted
with the optional electric
ignition system)
Cooling fan inlet grille
(only for panels fitted
with the motor invertor
drive units)
