Control Box For The Air/Fuel Ratio (Lmv52 - Riello RS BLU Series Installation, Use And Maintenance Instructions

4.11

Control box for the air/fuel ratio (LMV52...)

Warnings
To avoid accidents, material or environmen-
tal damage, observe the following instruc-
tions!
The LMV52 control box... is a safety device!
WARNING
Avoid opening or modifying it, or forcing its
operation.
Riello S.p.A. cannot assume any responsibili-
ty for damage resulting from unauthorised in-
terventions!
Risk of explosion!
An incorrect configuration can provoke fuel
overcharging, with the consequential risk of
explosion!
 All interventions (assembly and installation operations,
assistance, etc.) must be carried out by qualified personnel.
 Before modifying the wiring in the LMV52... control box con-
nection area, fully disconnect the system from the power
supply (omnipolar separation). Check the system is not pow-
ered and cannot be accidentally reconnected. Failure to do
this will lead to the risk of electrocution.
 Protection against electrocution from the LMV52... control
box and all connected electric components is ensured by
correct assembly.
 Before any intervention (assembly and installation opera-
tions, assistance, etc.), ensure the wiring is in order and that
the parameters are correctly set, then make the safety
checks.
 Falls and collisions can negatively affect the safety func-
tions.
 In this case, the control box must not be operated, even if it
displays no evident 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.
As for automatic operation, the actuators are guided togeth-
er to the positions requested and, if an actuator does not
reach the position requested, adjustments are made until
the position is actually reached. However, in contrast to au-
tomatic operation, there are no time limits to these corrective
actions. The other actuators maintain their positions until all
actuators have reached the positions currently required.
This is absolutely important to set the fuel / air ratio control
system. During the time the fuel / air ratio curves are being
programmed, the person making the plant settings must
continuously monitor the quality of the combustion process
(e.g. by means of a flue gas analyser). Also, if combustion
levels are poor, or in the event of dangerous situations, the
commissioning engineer must take appropriate action (e.g.
switching off manually).
To ensure the safety and reliability of the LMV52... system, the
following instructions must also be followed:
– Avoid conditions that can favour the development of conden-
sate and humidity. Otherwise, before switching on again,
make sure that the entire control box is perfectly dry!
– Static charges must be avoided since they can damage the
control box's electronic components when touched.
20085953
Technical description of the burner
Mechanical structure
The LMV52... control box is a system to check the burners, based
on a microprocessor and equipped with components to adjust
and monitor medium and large capacity forced draught burners.
The base control box of the LMV52... system incorporates the fol-
lowing components:
• Burner adjustment device with system for checking the seal of
• Electronic fuel/air ratio monitoring device with a maximum of 6
• Optional PID temperature / pressure controller (load control-
• Optional VSD module Mechanical design
Installation notes
• Check the electric wiring inside the boiler complies with the na-
• Do not confuse the powered conductors with the neutral ones.
• Make certain that strain relief of the connected cables is in
• Ensure that spliced wires cannot get into contact with neigh-
• Arrange the HV ignition cables separately, as far as possible
• The burner manufacturer must protect unused AC 230V termi-
• When wiring the unit, make sure that AC 230V mains voltage
Electrical connection flame detector
It is important for signal transmission to be almost totally free of
any disturbances or loss:
•
14 GB
D9301
the gas valves
(LMV52...) actuators
ler)
tional and local safety regulations.
compliance with the relevant standards (e.g. as per DIN
EN 60730 and DIN EN 60 335).
bouring terminals. Use adequate ferrules.
from the control box and the other cables
nals with dummy plugs (refer to sections Suppliers of other ac-
cessory items).
cables are run strictly separate from extra low-voltage cables
to avoid risks of electrical shock hazard.
Always separate the detector cables from the other cables:
– The capacitive reactance of the line reduces the size of the
flame signal.
– Use a separate cable.
Fig. 7