Reznor YDSA Unit Installation Manual - Manual (Page 46)

Form I-Y, P/N 273646R6, Page 46
Gas Pressure Tap Location
Locate the 1/8” pressure taps on both manifolds. (See FIGURE 24B, page 43). Both
high-fire and low-fire pressure can be checked at the manifold pressure taps.
With the manual valve turned OFF, connect a manometer to the 1/8” pressure tap on
the manifold in Heat Section 1. Open the manual valve.
Unit Test Mode Must be Enabled - Refer to Paragraph 10.3 to enable Test Mode
Follow the instructions to enter Test Mode and proceed to Test Mode Screen E.a.5.
Manifold Pressure Measurements
From the Test Mode Screen E.a.5:
•
Press the enter key until the cursor is flashing on the Heat Capacity: field. Adjust the
Heat Capacity value to 100% which will result in a signal of 10vdc to the modulating gas
valve.
•
Press the enter key until the cursor is flashing on the
Stg 1: field. Press the up arrow to set the Stg 1 value to ON.
•
Press the enter key until the cursor is flashing on the
Stg 2: field. Press the up arrow to set the Stg 2 value to ON.
•
Press the enter key until the cursor is flashing on the
Stg 3: field. Press the up arrow to set the Stg 3 value to ON.
Step 1 - High-Fire Manifold Pressure Reading Heat Section 1
Using the manometer, measure the pressure on high fire. Check the pressure with
the chart on page 49. Normally adjustments to the factory settings should not
be necessary.
• If no adjustment is required, proceed to Step 5.
• If an adjustment is required, proceed to Step 2.
Step 2 - Single-Stage Valve Output Pressure Heat Section 1
Set the value of Stg 1, 2 and 3 to OFF. Locate the output pressure tap on the top of
the single-stage valve. Close the manual valve and connect a second manometer to
the 1/8” output pressure tap on the single-stage valve. Open the manual valve. Set the
value of Stg 1, 2 and 3 to ON and measure the gas pressure.
If the output from the valve is not correct, remove the cap from the adjustment screw on
the single-stage valve. Adjust the output pressure setting by turning the regulator screw
IN (clockwise) to increase pressure. Turn the regulator screw OUT (counterclockwise)
to decrease pressure. Replace the cap.
CAUTION: DO NOT bottom out the gas valve regulator adjusting screw. This
can result in unregulated manifold pressure causing excess over fire and heat
exchanger failure.
Cycle the burner by turning the value of the Stg 1 field OFF and ON to actuate the
valve.
When the outlet pressure is correct, set the value of Stg 1, 2, and 3 to OFF. Close the
manual valve and remove the manometer. Open the manual valve and proceed to
Step 3.
Step 3 - Rechecking High-Fire Manifold Pressure Heat Section 1
Set the value of Stg 1, 2, and 3 to ON. Recheck the pressure at the manifold tap in the
high fire condition (Heat capacity field 100% 10vdc). Check the pressure with the
chart on page 43. Normally adjustments to the factory settings should not be
necessary.
Instructions for
Measuring Manifold
Pressure - Option AG74
(modulation with two
heat sections)
NOTE: Two digital
manometers may be
required.
9.2.2 Checking Gas Pressure (cont’d)
9.2 Gas Heat Section (cont’d)
9.0 Optional Equipment including Heat Sections (cont’d)