Great Plains 3PYPA Operator Manual - Manual (Page 92)

88 3PYPA Table of Contents Index Great Plains Manufacturing, Inc.
401-647M Table of Contents Index 03/20/2012
Seed Pool Recovery
When a meter has been starved of seed, back-flow of air
through the open shutter reduces delivery air flow. This
causes seed delivery to be slow. If you start or resume
planting with an empty seed pool, the delivery flow may
be too low to keep the meter supplied. The steps below
quickly “prime” the meter by rebuilding the seed pool.
Refer to Figure 119 (which depicts a recovery after an inci-
dence of bridging at air release screen)
1.
Close the shutter . This stops the air back-flow.
2. Clear the bridge or blockage that caused the
meter to run empty.
3. With the fan running, listen for seed to fall into the
inlet.
4. Wait for seed fall to taper off and stop.
5. Open the shutter to the operating setting.
6. Start or resume planting.
Magnehelic
a
Gauge Troubleshooting
If the Magnehelic® gauge does not read zero with the
fan off, or the reading disagrees with the seed monitor
sensor reading by more than a few tenths of an inch of
water pressure, inspect the gauge, and re-zero as
needed.
Check for chamber and breather line problems before re-
zero. Re-zero cannot accurately compensate for leaks
and blockages.
Re-zero the Magnehelic® gauge on level ground with the
fan off, and if possible, under no-wind conditions. Turn
the set screw
on the meter face until it reads zero from
the tractor driver’s viewing position.
Metadata: End of “Seed Pool Troubleshooting“
a. Magnehelic is a registered trademark of Dwyer Instruments, Inc.
Problem Cause Solution
Non-zero
with fan off Zero drift Re-zero per instruc-
tions below
Gauge
reading
lower than
sensor Relief port plug
missing/damaged Replace plug
Breather line
blocked or kinked Clear breather line
Leak in sensing
line Check line to cham-
ber
Gauge damaged Check for loose
cover, damaged
O-ring
29744
Null4:
Figure 119
Seed Pool Recovery
29744
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4
5
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3
4
5
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Null4:
Figure 120
Magnehelic® Gauge
29842
Port ID for Troubleshooting:
Over-pressure relief port (with plug in place)
Low-pressure port (breather/atmospheric pressure)
High-pressure port (from manifold chamber)
Alternate high/low ports are plugged.
Winter testing/maintenance advisory:
Gauge readings may be inaccurate or sluggish below
20
°F
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3
4
3
2
4
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