Rapid 7500 136 Installation, operation & service manual - page 66
7500-S
ERIES
I
NSTALLATION
, O
PERATION
AND
S
ERVICE
M
ANUAL
54 of 143
press
u
re is the lo
w
gas press
u
re s
w
itch. The lo
w
gas
press
u
re s
w
itch m
u
st
b
e set to the minim
u
m req
u
ired
gas press
u
re as indicated on the data plate.
The high gas press
u
re s
w
itch m
u
st
b
e set to 1"
w
c
(2.5 m
b
ar) a
b
o
v
e the high fire setting esta
b
lished
d
u
ring commissioning.
If either s
w
itch senses a press
u
re
w
hich is lo
w
er (lo
w
gas press
u
re s
w
itch) or higher (high gas press
u
re
s
w
itch) than its set point, then the s
w
itch
w
ill open
and lock o
u
t, sh
u
tting the
bu
rner do
w
n. The s
w
itch
w
ill ha
v
e to
b
e reset man
u
ally, once the condition has
b
een corrected.
14.5.6 Flame Control
This de
v
ice
w
ill check for
b
oth pilot flame and main
flame (main flame only on oil fired eq
u
ipment)
w
ithin
the
bu
rner. When a flame signal from the pilot flame
is a
v
aila
b
le (on gas-fired eq
u
ipment), it
w
ill allo
w
the
main gas
v
al
v
e to open.
If the pilot flame (gas-fired) or the main flame signal
(oil-fired) is not present, the electrical signal cannot
b
e contin
u
ed so the pilot
v
al
v
e (gas-fired) or main
v
al
v
e (oil-fired)
w
ill close. If ignition does not occ
u
r,
the flame safeg
u
ard relay
w
ill locko
u
t, and m
u
st
b
e
man
u
ally reset. (See the Tro
ub
le-Shooting G
u
ide -
)
14.5.7 Dischar
g
e Temperature Sensor
This de
v
ice senses the discharge temperat
u
re of the
air t
u
rno
v
er
u
nit. The discharge temperat
u
re sensor
reports the discharge temperat
u
re to the
bu
rner
control de
v
ice. Sho
u
ld this system fail, the a
u
tomatic
and man
u
al high temperat
u
re limit s
w
itches
w
ill t
u
rn
the
bu
rner off. DDC-ready air t
u
rno
v
er
u
nits do not
come eq
u
ipped
w
ith this sensor and m
u
st
b
e field-
s
u
pplied.