Great Plains NP30A 30-foot Operator Manual - Manual (Page 100)

96 NP30A or NP40A Table of Contents Index Great Plains Manufacturing, Inc.
407-502M Table of Contents Index 2014-05-20
Anhydrous Coulter Spring Setting
If the NH
3
coulter is ever disassembled for maintenance,
reset the spring length to factory setting. Raise the
applicator to ensure that the coulter is relaxed.
Refer to Figure 79
At the rear end of the spring
, loosen the outer jam nut.
Adjust the inner nut for a spring length of:
10
3 ⁄
8
inches (26.4 cm)
This corresponds to a vertical trip force of
1557 pounds (705 kg).
Machine Damage Risk:
Do not attempt to compensate for extreme field conditions by
adjusting the springs to higher forces (shorter springs).
Higher trip force is not likely to improve penetration, and
results in premature blade wear, higher risk of blade damage,
and may simply lift the applicator.
Anhydrous Coulter Castering
Coulters may be operated locked in-line, or with limited
free castering.
Refer to Figure 80
To lock the coulter, loosen the jam nut at
. Align the
coulter front to back. Tighten the set screw at , then the
jam nut.
To unlock the coulter, loosen the jams nut at . Loosen
the set screw bolts at , then tighten the jam nuts.
Note: Do not loosen the stop bolts .
Anhydrous Coulter Blade Wear
Blade wear is normal and the rate of wear varies with
field conditions and operating depth. Consider replacing
the blade when the initial diameter has been reduced by
1 to 2 inches.
Note: Although a nominal 22 inches in diameter, blades
are lightly larger.
2
1
Figure 79
Coulter Spring Length
34929
1
2
2
b
b
a
Figure 80
Anhydrous Coulter Castering
34929
a
a
a
a
b