Trane GHND-SVX01A-EN - Manual (Page 33)

GHND-SVX01A-EN • High Efficiency Propeller Fan Gas Unit Heater 33
Operation
PRIMARY AIR SHUTTER ADJUSTMENT
After the unit has been operating for at least 15 minutes, adjust the primary air flow to
the burners. Turn the friction-locked, manually-rotated air shutters clockwise to close, or
counterclockwise to open.
Note: IMPORTANT! For correct air adjustment, close the air shutter until yellow tips
in the flame appear. Then open the air shutter to the point just beyond the
position where yellow tipping disappears. Refer to Figure 19, Main burner
flames.
Note: There may be momentary and spasmodic orange flashes in the flame. This is
caused by the burning of airborne dust particles, and not to be confused with the
yellow tipping, which is a stable or permanent situation when there is insufficient
primary air.
PILOT ADJUSTMENT
1. Remove the pilot adjustment cap.
2. Adjust the pilot screw to provide a properly sized flame.
3. A proper pilot flame is a soft steady flame that envelops 3/8 to 1/2-inch (9.5 to 12.7
mm) of the flame sensor.
4. Replace the pilot adjustment cap.
MANIFOLD PRESSURE ADJUSTMENT
If the manifold pressure requires minor adjustment, remove the cap from the pressure
regulator and turn the adjustment screw clockwise to increase the pressure, or
counterclockwise to decrease the pressure. The adjusted manifold pressure should not
vary more than 10% from the pressures specified in Table 5.
Figure 19. Main burner flames
Y E LLOW T IP P ING
(MAR G INAL)
LIF T ING
(T OO MUC H AIR )
NOR MAL
(HAR D F LAME )
Y E LLOW F LAME
(T OO LIT T LE AIR )