UNITED FIRE SYSTEMS -
NITROGEN-
PAC™
MODEL SC-W
INSTALLATION, COMMISSIONING, AND MAINTENANCE MANUAL
REVISION 1.01 MAR 2021 - P/N 30-NPWICM-000
58
4.2. STARTUP.
Step
Procedure
Startup 1
Operate panelboard circuit breaker to
ON
.
Startup 2
Operate
POWER
switch to
ON
.
GREEN
power indicator will illuminate, and air compressor
should start.
Startup 3
Gauge
A
should begin to indicate pressure.
SYSTEM IS READY FOR 30 MINUTE INITIAL FILL
– PROCEED TO 4.3.1. OR 4.3.2.
IF SYSTEM IS
TYPE
I
(INITIAL-FILL BY
INTERNAL
COMPRESSOR),
PROCEED TO 4.3.1
– 30 MINUTE INITIAL FILL (TYPE
I
SYSTEM).
IF SYSTEM IS
TYPE
II
(INITIAL-FILL BY
EXTERNAL
COMPRESSOR),
PROCEED TO 4.3.2
– 30 MINUTE INITIAL FILL (TYPE
II
SYSTEM) .
4.3.1. 30 MINUTE INITIAL FILL (TYPE
I
SYSTEM
).
Step
Procedure
Initial Fill 1
Refer to
Figure 34
. Move Valve
1
to
BYPASS
position (handle facing
LEFT
).
RED
Bypass visual
indicator should be flashing
ON
.
Initial Fill 2
OPEN
inlet valve on one (1) Model NAMD-1. NAMD-1 pressure gauge should indicate pressure.
Initial Fill 3
Adjust NAMD-1 regulator to indicate gauge pressure approximately 5-10% above minimum
pressure required by low air supervisory switch. Examples:
If low air supervisory switch operates at 13 PSI, adjust NAMD-1 regulator so that gauge
indicates approximately 15 PSI.
If low air supervisory switch operates at 40 PSI, adjust NAMD-1 regulator so that gauge
indicates approximately 44 PSI.
IN NO CASE should regulator be adjusted for pressure higher than can be handled by sprinkler
valve.
Initial Fill 4
CLOSE
Model NAMD-1 Inlet Valve, and
OPEN
NAMD-1 Bypass Valve.
Initial Fill 5
After 30 minutes or less, required valve supervisory pressure should be reached.
CLOSE
NAMD-
1 Bypass Valve as soon as possible to avoid overpressurizing. Low air supervisory switch should
be satisfied. Signal indicating low pressure should not be present when control unit is reset. If
supervisory pressure is
NOT
reached in 30 minutes or less, troubleshoot sprinkler system for
leaks. If supervisory pressure still cannot be reached, contact
UNITED
Fire Systems
.
Initial Fill 6
If Model SC-W assembly is connected to two (2) sprinkler valves, repeat Initial Fill steps 1 through
6 for the second valve.
SYSTEM IS READY FOR PURGING
– PROCEED TO 4.4. – PURGING.
4.3.2. 30 MINUTE INITIAL FILL (TYPE
II
SYSTEM).
Step
Procedure
Initial Fill 1
Refer to
Figure 34
. Move Valve
1
to
BYPASS
position (handle facing LEFT).
RED
Bypass visual
indicator should be flashing
ON
.
Initial Fill 2
CLOSE
all valves on Model NAMD-1 connected to outlet of external air compressor.
Initial Fill 3
Apply AC power to external air compressor. Compressor motor should start.
Initial Fill 4
OPEN
inlet valve on Model NAMD-1 connected to outlet of external air compressor.
Initial Fill 5
Adjust the setting of the regulator on this Model NAMD-1 to
be
BELOW
but close to the low air
supervisory switch setting of the sprinkler valve. In the case of a dry-pipe sprinkler valve, this
setting should also be as high as possible
ABOVE
the pressure where the dry-pipe valve trips.
Each system installation requires examination based on the brand and model of sprinkler valve,
and the supplied water pressure. Refer to
Table 10
for an example.
Summary of Contents for Nitrogen Pac SC-W
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