UNITED FIRE SYSTEMS -
NITROGEN-
PAC™
SC-W SERIES
INSTALLATION, COMMISSIONING, AND MAINTENANCE MANUAL
REVISION 1.01 MAR 2021 - P/N 30-NPWICM-000
69
SYMPTOM
INDICATION(S)
PROBLEM
SOLUTION
MANUAL
REFERENCE
Excessive compressor
runtime (more than 2-1/2
hours per day) after
purging
Runtime indicator
indicates more than 2-
1/2 hours of runtime in
a 24 hour period.
Compressor intake
filter is clogged
Replace intake filter
5.4.1
Particulate and / or
coalescing filters are
clogged
Replace filter
elements
5.4.4
Leakage in piping
between Model SC-W
assembly outlet and
Model NAMD-1
Repair all leaks.
Leakage at Model
NAMD-1
Repair all leaks.
Excessive leakage in
sprinkler piping
Repair leaks until
leakage is minimized
Model SC-W
assembly regulator
drift
When compressor is
running, check
Gauge
A
for reading
of 100 PSI.
If Gauge
A
reading is too
low, contact
UNITED
Fire
Systems
Low air signal
Control panel
monitoring sprinkler
valve indicates
SUPERVISORY
–
LOW AIR condition
Model NAMD-1
valves not properly
positioned
Position Model
NAMD-1 ball valves
properly
Table 11
Model NAMD-1
regulator not properly
adjusted
Adjust Model
NAMD-1 regulator to
correspond with
required supervisory
pressure
Appendix B
Compressor is not
able to “keep up”
Refer to
“Excessive compressor runtime
(more than 2-1/2 hours per day) after
purging” above
High air signal
Control panel
monitoring sprinkler
valve indicates
SUPERVISORY
–
HIGH AIR condition
Model NAMD-1
regulator not properly
adjusted
Adjust Model
NAMD-1 regulator to
correspond with
required supervisory
pressure
Appendix B
Inadvertent dry-pipe
valve tripping during
purging
Presence of quick-
opening device (dry
accelerator)
Refer to
2.6.9
for information on dealing
with the presence of a quick-opening
device (dry accelerator)
Summary of Contents for Nitrogen Pac SC-W
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