4.12
Control box for the air/fuel ratio (LMV51...)
Warning notes
To avoid injury to persons, damage to property
or the environment, the following warning notes
must be observed!
The LMV51... is a safety device!
WARNING
Do not open, interfere with or modify the unit.
Riello S.p.A. will not assume responsibility for
any damage resulting from unauthorized inter-
ference!
Risk of explosion!
Incorrect configuration can lead to excessive fuel
supply which might cause an explosion!
Operators must be aware that incorrect settings
made on the AZL5... display and operating unit
and incorrect settings of the fuel and / or air actu-
ator positions can lead to dangerous burner oper-
ating conditions.
All activities (mounting, installation and service work, etc.)
must be performed by qualified staff.
Before making any wiring changes in the connection area of
the LMV5..., completely isolate the plant from mains supply
(all-polar disconnection). Ensure that the plant cannot be
inadvertently switched on again and that it is indeed dead. If
not observed, there is a risk of electric shock hazard.
Protection against electrical shock hazard on the LMV5...
and on all connected electrical components must be
ensured through appropriate mounting.
Each time work has been carried out (mounting, installation
and service work, etc.), check to ensure that wiring is in an
orderly state, that the parameters have been correctly set
and make the safety checks.
Fall or shock can adversely affect the safety functions.
Such units must not be put into operation even if they do not
exhibit any damage.
In programming mode, the position check of actuators and
VSD (checking electronic fuel / air ratio control) is different
from the check during automatic operation.
Like in automatic operation, the actuators are still jointly
driven to their required positions. If an actuator does not
reach the required position, corrections are made until that
position is reached.
However, in contrast to automatic operation, there are no
time limits to these corrective actions.
The other actuators maintain their positions until all actua-
tors have reached the positions currently required.
This is essential for setting fuel /air ratio control. This means
that during the time the fuel / air ratio curves are pro-
grammed, the person making the plant settings must contin-
uously monitor the quality of the combustion process (e.g. by
means of a flue gas analyzer).
Also, if combustion levels are poor, or in the event of danger-
ous situations, the commissioning engineer must take
appropriate action (e.g. switching off manually).
To ensure the safety and reliability of the LMV5... system, the
following points must also be observed:
– Condensation and ingress of humidity must be avoided.
Should such conditions occur, make sure that the unit will be
completely dry before switching on again!
– Static charges must be avoided since they can damage the
unit's electronic components when touched.
All manuals and user guides at all-guides.com
Technical description of the burner
13
GB
Mechanical design
The LMV5... is a microprocessor-based burner management sys-
tem with matching system components for the control and super-
vision of forced draft burners of medium to large capacity.
The following components are integrated in the basic unit of the
LMV5...:
• Burner control with gas valve proving system
• Electronic fuel / air ratio control with a maximum of 4
(LMV51...) or 6 (LMV52...) actuators
• Optional PID temperature / pressure controller (load control-
ler)
• Optional VSD moduleMechanical design
Installation notes
• Ensure that the electrical wiring inside the boiler is in compli-
ance with national and local safety regulations.
• Do not mix up live and neutral conductors.
• Make certain that strain relief of the connected cables is in
compliance with the relevant standards (e.g. as per DIN EN
60730 and DIN EN 60 335).
• Ensure that spliced wires cannot get into contact with neigh-
boring terminals. Use adequate ferrules.
• Always run high-voltage ignition cables separately while ob-
serving the greatest possible distance to the unit and to other
cables
• The burner manufacturer must protect unused AC 230 V ter-
minals with dummy plugs (refer to sections Suppliers of other
accessory items).
• When wiring the unit, ensure that AC 230 V mains voltage ca-
bles are run strictly separate from extra low-voltage cables to
warrant protection against electrical shock hazard.
D9301
Fig. 6
20010309