Rapid 4044, Installation, Operation & Service Manual

Page: 123 / 162

SECTION 20: D
IRECT
F
IRED
B
URNER
115 of 154
20.1 Direct Fired Burner I g nition
The b u rner that is u sed in the Rapid Engineering
LLC u nit is eq u ipped w ith a pilot assembly. The pilot
assembly consists of a pilot gas t u be, spark
electrode or rod and a flame rod w ith gro u nding
assembly. For proper ignition the spark rod m u st be
adj u sted correctly. A high v oltage arc is generated
bet w een the spark rod and the pilot gas t u be. The
gas flo w ing o u t the ports in the pilot gas t u be is
ignited by this arc. The arc w ill be a brilliant electric
bl u e in color. See Page 115, Figure 72 .
FIGURE 72: Spark Rod Dimensions
The gas s u pplied to the pilot gas t u be sho u ld be 3 1/
2" w c for nat u ral gas and bet w een 9 to 11" w c for
propane or LP. The difference bet w een the t w o f u els
is that a restricting orifice is installed in the propane
or LP pilot gas t
u be. The pilot assembly can be u sed
on propane or LP w itho u t an orifice, if this is the case
then the press u re for LP is 2.0" w .c. Ignition w ill take
place w ith the introd u ction of gas to the pilot gas
t u be. The pilot flame w ill be mostly bl u e in color w ith
streaks of yello w . The flame size w ill be ro u ghly 2" in
diameter. The flame m u st be steady and consistent
in size.
B
C
E
D
A
WARNING: the ignition system on the air handler generates bet w een 6,000 to 10,000 v olts.
A B C D E
in 2.940 0.125 0.125 1.881 0.633
cm 7.468 0.318 0.318 4.778 1.608