Metering system troubleshooting – Great Plains NP3000A Operator Manual User Manual
Page 102

98
NP3000 and NP3000A
Great Plains Manufacturing, Inc.
407-613M
2014-04-22
NH
3
Metering System Troubleshooting
Problem
Cause
Solution
Pressure Spikes (no
alarm)
Plugged tine or tines
Stop application per page 64. Lift
applicator and inspect tines. Clear
any plugging per “Clearing Plugged
Tines” on page 110.
Flow divider pressure
sag
Open line or lines
Stop application per page 64. Lift
applicator and inspect tines for open
line plugging. Clear any plugging per
“Clearing Plugged Tines” on
page 110
Temperature Rise (no
alarm)
Plugged refrigerant vapor line
Stop application per page 64. Lift
applicator and inspect tines. Clear
any plugging per “Clearing Plugged
Tines” on page 110.
Rate Alarm, Low
System not fully charged
Expect early rate alarms until the
cooler is ensuring that all meter flow
is liquid.
One or more manual valves not fully open
Suspend operations (per page 63).
Check all manual valves from nurse
tank withdrawal valve to emergency
shut-off valve.
Solenoid or control valve malfunction or
harness status
Suspend operation (page 63).
Close emergency shut-off valve.
Discharge line from emergency
shut-off valve to tines.
Wait for applicator to be safe to
approach.
Check harness connections and
fuses.
Use console SELF-TEST mode to
command Raven valves open. Check
valve ball indicators at valves.
Field speed too high (higher than available
pressure can supply NH
3
)
Slow down, or wait for warmer
conditions.
Tank pressure low
Ambient or tank temperature may be
too low to provide sufficient delivery
pressure. Wait for tank to warm, or
wait for warmer weather.