Electrical Connections; Bu Rn Er Start- U P - Ygnis BLU 7000.1 PR Manuel D'instructions

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420010391600 BLU 7000. 1 - 12000. 1 PR / M D
ELECTRI CAL CO N N ECTI O N S
All burners factory tested at 400 V 50 Hz three-phase for motors and 230 V 50 Hz monophase with neutral for auxi-
liary equipment. If mains supply is 230 V 50 Hz threephase withuot neutral, change position of connectors on burner
as in fig. Protect burner supply line with safety fuses and any other devices required by safety standards obtaining in the
country in question.
CO N N ECTI O N TO TH E G AS PI PELI N E
Once connected the burner to the gas pipeline, it is necessary to control that this last is perfectly sealed. Also verify that
the chimney is not obstructed. Open the gas cock and carefully bleed the piping through the pressure gauge connector,
then check the pressure value trough a suitable gauge. Power on the system and adjust the thermostats to the desired
temperature. When thermostats close, the sealing control device runs a seal test of valves; at the end of the test the bur-
ner will be enabled to run the start-up sequence.

BU RN ER START- U P

Before starting the burner, make sure it is mounted correctly. Then check connections are correct according to the dia-
gram and piping is appropriate to the system. Before connecting the burner to the electricity supply, make sure voltage
corresponds to burner plate data. The connection diagram and start-up cycle are shown separately. For wiring from
control box to burner, see the enclosed connection diagram. Pay particular attention to neutral and phase connections :
never exchange them!. Vent air and impurities of gas pipe. Check gas pressure conforms to the limits stated on the bur-
ner plate when connecting a master gauge to the test port provided on the burner. Blower motor starts and pre-purging
begins. Since pre-purging has to be carried out with the max. air delivery, the burner control circuit turns the air dam-
per to the max. delivery position by the air servocontrol in approximately 30 seconds time. When the servocontrol is
fully open, a signal to the electronic control unit starts the 66 seconds pre-purge cycle. At the end of the prepurging
time, the air servocontrol gets to the Low Flame position so that burner ignition is ensured at min. output.
Simultaneously the ignition transformer receives voltage and after 3 seconds (pre-ignition) opens the pilot gas valve.
Fuel flows to the combustion head and ignites. Two seconds after pilot gas valves have opened, the ignition transformer
is excluded from the circuit. In case of no ignition the burner goes to lock-out within two seconds. After 6 sec. open the
working gas valve, governed by the gas firing butterfly valve.Now the burner is operating at the min. firing rate (about
30% of the max. firing rate). The air servocontrol runs at the Low Flame position and in case the temperature control
has to be set at the max. output it goes to a fully open position of air damper and butterfly valve. During the burner-off
periods the air damper closes up fully.
AD J U STI N G TH E CO M BU STI O N PRO CESS
I M PO RTAN T:to obtain the right adjustment of the combustion and thermal capacity it is important to analyze the reducts of
combustion with the aid of suitable instruments. The combustion and thermal capacity adjustment is done simultaneously,
together with the analysis of the products of combustion, making sure that the measured values are suitable and that they comply
with current safety standards. On this matter, please refer to the table and figure below.
TH ESE O PERATI O N S M U ST BE D O N E BY PRO FESSI O N ALLY- QUALI FI ED TECH N I CI AN S.
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