Direct Gas Make-Up Air
29
Start-Up: Direct Gas-Fired Heating
All Units
Adjust fan RPM via adjustable motor sheaves (if
equipped), VFD (if equipped) or sheave replacement to
achieve proper burner pressure drop. Motor amp draw
must not exceed Full Load Amperage (FLA) on motor
nameplate. If fan RPM cannot be adjusted, evenly
adjust the baffles above and below the burner, keeping
the burner centered in the opening until the required
pressure is obtained. To increase the static pressure,
decrease the opening. To decrease the static pressure,
increase the opening. The pressure drop was set at the
factory and may not need adjustment. When required
pressure is obtained, be sure to reconnect the outer
sensing probes.
If burner baffles have been adjusted, this process
may need to be repeated until the proper pressure is
achieved. This adjustment will change the air quantity
delivered by the unit and therefore the air quantity
delivered should be rechecked. Reference the
Supply
Fan,
Start-Up
section in this Installation, Operation and
Maintenance Manual for more information.
7. Set the Low Fire Time Delay
Identify the type of Maxitrol amplifier installed.
Reference the
Start-Up:
Direct Gas-Fired Heating,
Optional Features, Temperature Control Identification
section in this Installation, Operation and Maintenance
Manual for more information
.
The Maxitrol Series 14 and
Series 44 have a DIP switch to control the low fire start
time. The Low Fire Start Time DIP switch must be set
to the 10 second position. The Maxitrol SC Series must
have the J3 jumper placed on pins 2 and 3 to ensure
low fire start occurs.
