Milnor 7272TG1L, Installation And Service

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Gas and Air Adjustments
PELLERIN MILNOR CORPORATION
1. Connect the high side of the manometer to test point 1 ( Figure 1 ). Leave the other side open
to the atmosphere.
2. Open the manual test valve fully (R, Figure 1 ).
3. Adjust the main gas regulator (W, Figure 1 ) to value shown in Table 2 or Table 3 .
2.9.
Step 6: Setting Burner Minimum Fire
Display or Action Explanation
u
This mode sets the modulating gas valve to 000 and displays
the inlet temperature (Fahrenheit shown).
SETUP MODE E 079F
MIN FIRE ROD GAS SW
1. Calculate the desired minimum fire temperature using data from Table 2 or Table 3 .
2. Slowly adjust the Y minimum adjustment on top of the modulating gas valve (T, Figure 1
and Figure 6 ). Turn adjustment CCW to increase the temperature or CW to decrease
temperature, until value calculated from data in Table 2 or Table 3 appears on control panel
display. After making an adjustment, wait for the dryer display to settle.
2.10.
Step 7: Setting High Gas Pressure Switch
1. Attach one side of manometer (high pressure side of differential pressure gauge) to test point
3 ( Figure 2 ); leave the other side open to atmosphere.
2. Set the high gas pressure switch dial (K, Figure 1 ) to the value in Table 2 or Table 3 .
3. Start with the manual test valve fully open. Close this valve slowly until value shown in
Table 2 or Table 3 is read on manometer.
4. Verify that when the set value is reached, the
$
light blinks, the switch trips, and the burner
extinguishes.
5. Open the manual test valve fully.
2.11.
Step 8: Setting Low Gas Pressure Switch
1. Connect one side of manometer (high pressure side of differential pressure gauge) to test
point 1 ( Figure 1 ); leave the other side open to atmosphere.
2. Start with the external gas shut-off valve open. Close this valve slowly until value shown in
Table 2 or Table 3 is read on manometer.
3. Slowly rotate the low gas pressure switch dial (L, Figure 1 ) until the
#
status light is on .
Open the external gas shut-off valve fully.
4. Slowly close the external gas shut-off valve and verify that when the value is reached, the #
slatus light blinks, the switch trips and the burner extinguishes.
5. Open the external gas shut-off valve fully.
2.12.
Step 9: Setting the Burner Pressure Switch
1. Put dryer in Setup Mode E, (see "Step 6: Setting Burner Minimum Fire.")
2. Attach the low pressure side of the manometer to the plenum air gauge point (item 2, Figure
10 ) and leave the other side open to the atmosphere.
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