2019-03-11
407-502M
NP30A or NP40A
Troubleshooting
108
Metering System Troubleshooting
Problem
Cause
Solution
Pressure Spikes (no
alarm)
Plugged knives or tines
Stop application per page 77. Lift applicator and inspect knives or
tines. Clear any plugging per “
Clearing Plugged Knives or Tines
Flow divider
pressure sag
Open delivery line or lines
Stop application per page 77. Lift applicator and inspect knives or
tines for open line plugging. Clear any plugging per “
Temperature Rise (no
alarm)
Plugged refrigerant vapor line
Stop application per page 77. Lift applicator and inspect knives or
tines. Clear any plugging per “
Clearing Plugged Knives or Tines
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 76). 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 76).
Close emergency shut-off valve.
Discharge line from emergency shut-off valve to knives or 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.
Rate Alarm, High
Incorrect VALVE CAL for Control
Valve or METER CAL for flow
meter.
Recheck console setup against values provided for components
Control Valve failed, or harness
status
Suspend operation (page 76).
Close emergency shut-off valve.
Discharge line from emergency shut-off valve to knives or tines.
Wait for applicator to be safe to approach.
Check harness connections and fuses.
Use console SELF-TEST mode to command rate to zero open.
Check valve ball indicators at valves. Command rate to maximum.
Check ball indicator.
Excess NH
3
Remaining
(but no alarms)
Incorrect console setup
Re-check METER CAL and BOOM CAL.
Field size different.
After ruling out metering problems, re-check geography.
Excessive gaps between
fertilizer applicator passes.
Gap between opposing pass end trenches should be one row
space (e.g. 30in)
Flow meter malfunction
Consult dealer.
NH
3
Consumption
Too High (but no
alarms)
Incorrect console setup
Re-check METER CAL and BOOM CAL.
Field size different.
After ruling out metering problems, re-check geography.
Excessive overlap
Gap between opposing pass end trenches should be one row
space (e.g. 30in). Also check tracks for unintended re-applications,
particularly if relying on GPS mapping.
Tank or system Leak
Suspend application. Carefully approach applicator and nurse tank
from up-wind. Check for leaks in
Flow meter malfunction
Consult dealer.