Combustion Head Setting; Modulation Minimum Output - Riello RS 50/E Installation, Use And Maintenance Instructions

4.8

Combustion head setting

Installation operations are now at the stage where the blast tube
and sleeve are secured to the boiler as shown in Fig. 13.
The fan part of the burner shall be completely back-
ward using the guides.
WARNING
4.8.1

Modulation minimum output

When the MIN output is within the value range given in Tab. H, the
gas ring 2) (Fig. 13) is adjusted to zero.
Model
RS 50/E 321 - 488
There are two possible cases:
A The MIN burner output is not in the values of Tab. H
In diagram (Fig. 14), depending on the MAX output, find the notch
to use for adjusting the air and the gas.
Proceed as follows.
Air adjustment (Fig. 13)
 Turn screw 4) until the notch identified is aligned with the front
surface 5) of the flange.
Gas adjustment (Fig. 13)
 Loosen screw 1) and turn ring 2) until the notch identified is
aligned with index 3).
 Tighten the screw 1) fully down.
Example:
the burner varies its output between:
MIN = 450 and MAX = 1650 MBtu/hr.
The MIN output of 450 MBtu/hr is not found in the values of Tab. H
and therefore diagram (Fig. 14) is valid, from which it results that
for a MAX output of 1650 MBtu/hr the gas and air adjustments are
done on notch 3, as in Fig. 13.
In this case the pressure load loss of the combustion head is given
by column A Tab. I, page 21.
Diagram (Fig. 14) shows the ideal settings for the ring 2)(Fig. 13).
If the gas supply pressure is too low to reach the max output oper-
ation pressure indicated in Tab. I, and if the ring 2)(Fig. 13) is not
fully open, it can be opened wider by 1 or 2 notches.
Continuing with the previous example, Tab. I indicates that for
burner with output of 1650 MBtu/hr a pressure of approximately
1.9" WC is necessary at test point 6)(Fig. 13).
If this pressure cannot be reached, open the ring 2)(Fig. 13) to
notch 4 or 5.
Make sure that the combustion characteristics are satisfactory and
free of pulsations.
MBtu/hr kW
94 - 143
Installation
AIR
Tab. H
Notches (Air = Gas)
B The MIN burner output is found in the values of the Tab. H
Air adjustment (Fig. 13)
 The same as the previous case: follow diagramm (Fig. 14).
Gas adjustment (Fig. 13)
 The gas ring 2)(Fig. 13) is always adjusted to position 0, irre-
spective of the MAX burner.
 In this case the pressure load loss of the combustion heads is
given by column B in Tab. I.
19
D2315
Burner max output
GAS
Fig. 13
D11847
Fig. 14
20053677