Grain Systems PNEG-1798 - Manual (Page 26)

7. Procedure
26 PNEG-1798 Tower and T-Series Dryers Vaporizer
ASCO 3/4" liquid valve solenoid.
NOTE: The ASCO 3/4" liquid valve is a normally closed (N.C.) valve and it must be ‘energized to
open’ for the performance of this test. The valve is activated by 120 volts AC applied to
the two (2) red leads coming from the body of the valve. There will actually be three (3)
wires on the solenoid, two (2) reds and one green wire.
(See Figure 7D on Page 15.)
Depending on when the vaporizer is installed; the electrical portion of the dryer may have
been completed prior to this test. The ASCO wires may already be in conduit and
connected to the panel wiring. Regardless of that this test can still be performed. If the
electrical contractor has not completed their portion of the wiring, the wiring will be
exposed as in
Figure 7D on Page 15 . If the electrical contractor has finished the wiring
there should be a 1/2" conduit LB or tee where the wires from the solenoid valve have
been terminated or connected with wire nuts. The wire nuts can be removed from the
solenoid’s two (2) red wires and one green wire at this location. Note any wire colors and
how they were terminated to ensure they are re-connected exactly ‘as found’.
7.4.6. Connect the 3 prong power cord of 6.5 to the ASCO 3/4" liquid valve wires that were identified in
the note preceding this step. Connect the wires as delineated in the following steps. Any field
wires that are disconnected, if applicable will need to be re-connected after the test completion.
Note the wire connections and colors.
7.4.7. Connect the 3 prong power cord’s black wire to one of the two (2) solenoid’s red wires by using
an orange wire nut.
7.4.8. Connect the 3 prong power cord’s white wire to the solenoid’s remaining red wire by using an
orange wire nut.
7.4.9. Connect the 3 prong power cord’s green ground wire to the solenoid’s green wire by using an
orange wire nut.
7.4.10. Connect or plug the cord’s 3 prong male end into a powered or live 120 volt AC receptacle or
extension cord.
7.4.11. Verify the ASCO liquid solenoid energized open by the audible click or pop at the solenoid valve.
Record that this action occurred on the data sheet.
NOTE: Most large nitrogen cylinders when full are approximately 2000-2500 PSIG depending on
the overfill percentage. For the purpose of this test the cylinder bottle’s pressure should
be at least 500-800 PSIG to allow for enough volume to fill the vaporizer coils and
piping and pressure depending on how many leaks there are and how long the system
is pressurized.
7.4.12. Slowly open the nitrogen cylinder’s valve by turning the cylinder’s hand valve knob in a
counterclockwise (CCW) direction. Verify there is a pressure indication on the regulator’s high
pressure gauge. Record the pressure reading on the regulator’s high pressure gauge on the
data sheet.
7.4.13. Close or verify closed the brass 3/4" liquid line manual isolation valve where the nitrogen hose
is connected.
7.4.14. Slowly adjust the regulator mounted on the nitrogen cylinder by turning the regulator’s handle in
clockwise (CW) direction. This should start providing a pressure indication on the regulator’s low
pressure gauge. Continue turning the regulator handle until there is approximately 200 PSIG on
the regulator’s low pressure gauge. Record the pressure reading on the regulator’s low pressure
gauge on the data sheet.
7.4.15. Using leak detection solution, verify there are no leaks on the nitrogen cylinder’s connection at the
regulator and the regulator gauges or at the hose connection from the regulator or at the
connection to the manual 3/4" manual isolation valve. Repair any leaks that were found before
proceeding to the next step.