F
IRE
F
LEX
®
N
2
B
LAST
®
Integrated Fire Protection System
O
WNER
'
S
O
PERATION
&
M
AINTENANCE
M
ANUAL
Page 18 of25
FM-076B-0-6A
5.3 OPERATION
5.3.1 Air supply Style "A"
See figure 5.3.
To apply air pressure:
Establish AC power for the air compressor by activating the
correspondent circuit breaker at the electrical distribution
panel. Close the air inlet drain valve
(E12)
. Start
compressor by activating the
compressor isolating
switch
(E15)
located within the unit (see figure 4.4).
If the air compressor motor fails to start or slows down
under load, shut the compressor off. Check that the supply
voltage agrees with the motor nameplate.
To close the air supply:
Turn off the compressor isolating switch
(E15)
(see
figure 4.4).
To adjust system air pressure (air compressor switch):
WARNING !
The cut-out/cut-in differential switch adjustment
screw (small screw to the right) is factory set. DO NOT
CHANGE ITS SETTING. Any unauthorized modification of
this setscrew adjustment will void the system warranty and
may also prevent the system from operating normally.
The air compressor cut-off pressure switch
(E2)
(shown in
figure 5.1 with its cover removed) has its air compressor
cut-out adjustment screw (middle screw) factory set. This
switch should not need any adjustment but if necessary,
follow the instructions below:
1. Remove the cover of the air compressor cut-off
pressure switch
(E2)
.
2. To raise the cut-out pressure of the air compressor,
turn the cut-out adjustment screw (middle screw) half a
turn CLOCKWISE.
3. Open the main drain valve
(D3)
and let the pressure
drop until the air compressor
(E1)
restarts. Check
pressure reading on the system pressure gauge
(E3)
when the air compressor stops. Repeat until the
desired pressure is reached (refer to table 5). Once all
is done, replace the cover on the switch
(E2)
.
Note:
Do not turn the cut-out adjustment screw (middle
screw) all the way down in one shot. Proceed by steps. Use
the same method turning the cut-out adjustment screw
COUNTER-CLOCKWISE to lower the air compressor cut-out
pressure.
Figure 5. - Front view of the air compressor cut-off
pressure switch
Turn clockwise to increase
both cut-out and cut-in
pressure adjustment
Factory set
DO NOT CHANGE !
FM-072Q-0-109B
5.3.2 Air supply Style "B"
See figure 5.4.
To apply air pressure:
Turn on upstream air supply. If the unit is equipped
with the optional dehydrator (refer to section 5.5), close
the air inlet drain valve
(E12)
and open the air shut-off
valve
(E14)
.
Open APMD
(E5)
input valve
(E6)
by placing handle in
line with valve body then open APMD
(E5)
output
valve
(E7)
by placing handle in line with the valve body.
In order to accelerate filling of sprinkler piping by air
pressure, bypass valve
(E8)
can be opened by placing
handle in line with valve body while piping is initially
filled by the air compressor. This valve
(E8)
must then
be closed (handle crossways to valve body) and kept in
this position once the system is filled with air.
To close the air supply:
Close APMD output valve
(E7)
by placing handle
crossways to valve body then close APMD
(E5)
input
valve
(E6)
by also placing handle crossways to the
valve body. Be sure bypass valve
(E8)
is closed
(handle crossways to valve body).
To adjust system air pressure:
Be sure APMD
(E5)
input valve
(E6)
and output
valve
(E7)
are both open (handle in line with the valve
body), and bypass valve
(E8)
is closed (handle
crossways to valve body) prior to performing this
operation. Loosen lock nut of the DMPA
(E5)
and turn
pressure adjustment nut clockwise to increase air
pressure or counter-clockwise to decrease pressure.
Tighten lock nut.
Note:
Depending on site conditions, the internal filter of
the APMD
(E5)
may need maintenance on a regular
basis. Refer to Viking Data Sheet #127 for more details.
