Operation - Unigas RX90 Installation Manual

OPERATION

BEFORE STARTING UP THE BURNER, BE SURE THAT THE MAIN SWITCH IS ON AND THE MANUAL SHUTOFF VAL-
VES ARE OPEN.
1 Turn to the "ON" position the main switch A, on the burner's control panel (see Fig. 28).
2 Check the control box is not locked (LED B, on) and eventually release it by means of the pushbutton C (reset - for more informa-
tion about the device, please refer to the manual's Appendix).
3 Check the series of thermostats or pressure switches gives the burner the start signal for operating (closed contact).
4 Check that the gas pressure in the gas network is sufficient (if the pressure is normal, the LED E lights up).
5 The gas proving system checking cycle starts: the proving system LC LED lights up when the cycle ends.
6 The fan motor starts, the actuator drives the air damper to the maximum opening position (LED G on); the pre-purge time
countdown starts now.
7 At the end of the pre-purgue time, the air damper moves to the ignition position (about 5°), the ignition transformer is energised
(LED I on), the solenoid gas valves EV1 and EV2 are energised (LEDs L and M on). As far as burners with pilot gas train, the pilot
gas valves open.
8 The flame must lights up within few seconds after the gas valves opening, otherwise the control box locks out. Few seconds after
the gas valves opening, the transformer is de-energised and the LED I turns off.The burner is now operating and at the same time
the servocontrol moves to the hi-flame position (90° - see page 28).
9 Some seconds after the gas valves opening, the burner starts the automatic operation: it automatically switches to low or high
flame stage (progressive PR- burners) or to the operation requested by the burner modulator (Fully modulating - MD buners)
according to the requirements of the plant. As far as the modulator is concerned, refere to the related manual.
H
G
C
LC
LB
Fig. 28 - Burner front panel
B
O
I
N
M E
L
F
D
A
VPS504
Key
A Main switch
P
B Lock-out LED
C Reset pushbutton for control box
D Reset pushbutton for gas proving system (only
for burners provided with Siemens LDU11)
E "Gas pressure switch signal " LED
F "Lock-out" LED for gas proving system
G Hi-flame operation LED
H Lo-flame operation LED
I "Ignition transformer operation" LED
L "EV2 opening" LED
M "EV1 opening" LED
N "Fan motor overload tripped" LED
O "Burner in stand-by" LED
P Burner Modulator (only on fully modulating bur-
ners)
40