Spec Air Series Technical Manual
17
Cambridge Air Solutions
c
To check the gas tightness of the shut-
off valve (SOV) in the gas train which
is farthest from the burner connect the
manometer to the leak test port between
the valves and verify that the manometer
is properly zeroed. Wait 30 seconds to
read the manometer. If the reading is
greater than 0
inch
WC, refer to the
Maintenance Instruction Section (page
32) for information on Gas Valve Cleaning
for the shut-off valve (SOV) gas valve and
retest. If the reading is 0
inch
WC, remove
the manometer and reinstall the pipe plug.
9. GAS TRAIN LEAK CHECK
a. Turn the blower and burner service
switches to the
“
LOCAL
”
position.
b. With the burner operating, spray the
complete gas train with leak detector
solution, checking all pipe connections and
plugs.
c. Turn the blower and burner service
switches to the
“
OFF
”
position.
WARNING:
Do not use flame to leak check piping.
WARNING:
Any gas leak detected must be repaired before
the ventilation air unit is placed into service.
10. MINIMUM FIRE SETTING
IMPORTANT
All access doors must be closed during this
procedure.
a. For units with an A1044 amplifier: Reinstall
#3 wire on the amplifier that was removed
in Step 7.b. (See page 15).
b. Connect a meter set to read DC
microamps (
m
A) in order to verify the
minimum fire flame signal during the
adjustment process. Connect the meter
by removing the red wire from terminal
FP of the flame safe
g
uard relay (FSR) and
attaching the positive lead of the meter to
terminal FP and the negative lead to the
red wire.
c. Turn the blower and burner switches to
the “LOCAL” position.
d. After the burner has ignited, remove the
#8 wire from the amplifier to drive the
modulating valve to minimum fire.
e. Look through the burner viewport in the
front of the unit to verify that the burner
flame is a very small ribbon (approximately
1-1/2" to 2
"
long
)
that is
evenly spread across the
burner (without gaps).
f. Verify that the minimum fire flame signal is
steady and above 2.0 microamps (
m
A).