Grain Systems PNEG-1702 - Manual (Page 87)

11. Service
PNEG-1702 ETL Listed GSI/FFI Portable Dryer Manual 87
4. Main Gas Orifice: With fuel shut off and gas purged from system, proceed as follows:
a. Disconnect the plumbing support brackets from the pipe train.
b. Disconnect gas solenoid valve coils. Be sure to mark their original locations.
c. Lift pipe (with orifice, solenoid valve and other parts attached), straight up and remove from
fan/heater housing. Orifice and other parts can now be removed from pipe train, if desired.
5. Reassemble: To reassemble parts, reverse the disassembly procedure and check the following:
a. Make sure all parts are thoroughly cleaned and open.
b. Use a dependable brand of high temperature pipe caulking compound when assembling gas
connections. Apply only a light coating onto male threaded end of fittings.
c. Solenoid valves and gas regulations are directional and must be properly installed. Do not attempt
to connect gas solenoid valves by applying force to the valve core stem as it may ruin the unit.
d. Make sure all electrical wires are properly connected. Refer to wiring diagrams on Pages 89-107 .
Metering Roll Servicing
This dryer is equipped with an SCR metering roll drive assembly. The metering rolls are driven by a
separate DC type electric motor. The speed of the motor is variable and is controlled by an electric
SCR control within the main control box.
Main Controls
1. SCR Speed Control 4" (GSI): The metering roll speed pots on the front of the control box regulate
the speed of the DC motor which drives the metering rolls. 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.
NOTE: When the control is set to the maximum discharge rate (999), the metering roll speed should
be 17.5 RPM for 8" discharge auger.
SCR Speed Control 7" (FFI): The metering roll speed pots on the front of the control box regulate
the speed of the DC motor which drives the metering rolls. 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
NOTE: When the control is set to the maximum discharge rate (999), the metering roll speed should
be 4.3 RPM for 8" 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 gearbox assembly. The DC motor requires no operational adjustment as it
is completely controlled from the control box.
3. Speed Reducer Gearbox: The direct drive gearbox provides the required speed reduction and
transmits power to the metering rolls through a drive chain arrangement. The gearbox does
not require adjustment. The drive chain should also be periodically lubricated and tightened
as necessary.