Grain Systems PNEG-950 - Manual (Page 63)

PNEG-950 63
The scale of adjustment is from 0 to 999 which represents the flow of grain past the metering rolls as a
percent of the maximum grain discharge rate for the dryer. The maximum setting of 999 provides a maximum
100% discharge of 1960 BPH (50 MT / hr) for 1214, 2240 BPH (57 MT / hr) for 1216, 2520 BPH (64 MT / hr)
for 1218, 2800 BPH (71 MT / hr) for 1220, 3080 BPH (78 MT / hr) for 1222, 3640 BPH (92 MT / hr) for 1226
model dryers.
Note: When the control is set to the maximum discharge rate (999), the metering roll speed should be
17.5 RPM for 8" (20 cm) discharge auger.
2. DC electric motor: The direct current (DC) motor provides the drive for the metering roll, and is located
on the front left hand side of standard model dryers. The output shaft of the motor is connected directly to the
gear box assembly.The DC motor requires no operational adjustment as it is completely controlled from the
control box.
3. Speed reducer gear box: The direct drive gear box providesthe required speed reduction, and transmits
power to the metering rolls through a drive chain arrangement. The gear box does not require adjustment. The
drive chain should also be periodically lubricated and retensioned as necessary.
4. Unload auger time delay: The delay controls the bottom auger system and causes the unload auger (and
any connected auxiliary unloading conveyors) to continue operating for a programmed amount of time, even
after the metering rolls stop. This feature permits the cleanout of grain within the unloading equipment at the
end of all discharge cycles.
5. If a foreign object becomes lodged in the metering rolls and jams the system, the unloading auger will stay
in motion. However, the metering roll drive will stop and the DC motor should stall out. The Network Control
System will shut down the dryer after a two minute period.
To determine if the metering problem is from blockage, perform the following test with the power off. Remove
the drive chain by loosening the motor mounting bolts. Refer to photo, and place a pipe wrench on the hub of
the roller chain sprocket, on the left hand metering roll at the drive end of the dryer. Apply up to 100 ft.lbs. (136
N-m) of force, and attempt to rotate the roll toward the inside of the dryer. If the metering roll will turn, then
repeat for right hand side. If the metering roll will turn, it can be assumed that no blockage exists, and the
problem is from some other cause. Check for a break in the power train, chain, drive key, pin, etc.
CAUTION : Keep hands away from sprocket teeth to avoid injury from chain backlash, as a result of
torsion build up in the system caused by the jam.
HOW TO CLEAR A JAMMED METERING ROLL
Place a pipe wrench on the hub of the sprocket of the jammed metering roll and turn the roll. First, backward,
and then, forward several times in an attempt to dislodge the object, and clear it through the roll. If this is not
successful, have an assistant turn the metering roll, and attempt to locate the jam by sound. Shut down the
fan/heater, and eliminate any other noise when making this check. Once the location is determined, the roll
can be reached from the outside by opening the access door to remove the foreign object causing the jam
(before opening doors see below). The service tool must be inserted before opening doors. First, swing open
the plenum bottom closure panel. Insert the service tool above the metering roll.