I.C.E. HTDM Food Process Unit - Manual (Page 33)

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displayed the actual voltage to being sent the valve is displayed
(1/2 system tune voltage). Once the valve has reached the low
fire set point allow 10 seconds for sufficient sampling time of
the fan speed.
Click the “Next” button and the system will now display the second
combustion point. Press “Send” to drive the system to this
combustion point. Allow the actuator to travel and stop at the
correct voltage. Allow 10 seconds to achieve an accurate rpm
reading. Repeat the process until the high fire set point is
reached. Press “Exit” to return to the main screen. After a few
second the system will update the combustion points and the
updated tachometer readings will be displayed.
Adjusting Combustion Points
The following tachometer and valve set points provide a rough
guideline.
Point #1: 1200-1800 rpm, 2.5Vdc (5.0Vdc in system tune)
Point #2: 1800-2200 rpm, 3.5Vdc (7.0Vdc in system tune)
Point #3: 2200-2500 rpm, 4.5Vdc (9.0Vdc in system tune)
Point #4: 2400-2700 rpm, 5.5Vdc (11.0Vdc in system tune)
Point #5: 2600-3000 rpm, 6.5Vdc (13.0Vdc in system tune)
Point #6: 3000-3400 rpm, 8.0Vdc (16.0Vdc in system tune)
It is very critical to maintain a minimum 200rpm separation
between combustion points. Once this rough curve has been
established override this system to high fire. Open the firing
valve and set the manifold pressure. Shut the firing valve and
force the system to low fire. Reopen the firing valve when the
system is at low fire. Walk the system through each point in the
combustion curve and check combustion making adjustments to the
gas valve voltage as necessary. Once complete exit system tune
and recheck complete curve. If the curve is satisfactory press
the “Write” button. Confirm that the program has been updated by
clicking the “Read” button.
High fire should be running between 5-7% oxygen, 7-9% CO
2
while at
low fire that number will vary from 18-20% oxygen, 0.1-1% CO
2
.
Remember as the dirt accumulates the combustion fan performance
will drop off so allow excess oxygen during initial factory set
up.