Great Plains NP4000B Operator Manual - Manual (Page 112)

108 2013+ NP4000/A/B Table of Contents Index Great Plains Manufacturing, Inc.
417-199M Table of Contents Index 2014-05-14
NH
3
Metering System Troubleshooting
Problem Cause Solution
Pressure Spikes (no
alarm) Plugged tine or tines Stop application per page 70. Lift
applicator and inspect tines. Clear
any plugging per “Clearing Plugged
Tines” on page 120.
Flow divider pressure
sag Open line or lines Stop application per page 70. Lift
applicator and inspect tines for open
line plugging. Clear any plugging per
“Clearing Plugged Tines” on
page 120
Temperature Rise (no
alarm) Plugged refrigerant vapor line Stop application per page 70. Lift
applicator and inspect tines. Clear
any plugging per “Clearing Plugged
Tines” on page 120.
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 69).
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 69).
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.