Power Flame C Series Installation & Operation Manual page 18

C16
Rev.304
Low Fire Operating Position Adjustment in addition to the
light off and high fire operating positions. (See manufacturer's
bulletin included with the burner.)
An additional temperature or pressure controller is added
to the system, which at a selected preset point will electrically
switch the Motorized Gas Valve and Air Dampers (3) to either
the low fire or the high fire position, as the system load
demand requires. Depending on system load conditions,
the burner can alternate indefinitely between the low and
the high fire positions without shutting down. When the
system demand is satisfied, the Motorized Gas Valve closes
(normally the burner will be in the low fire position at this
time) and the Air Dampers are returned to the light off
position, in preparation for the next operating cycle. The
Driver Arm (10) connected to the Motorized Gas Valve will
Figure 19
Typical Gas Burner with Full Modulation Fuel/Air Control Mode (Model C-G)
1
7
MECHANICAL OPERATION: This Full Modulation system
uses a Diaphragm (1) or Motorized Gas Valves to ensure
opening and positive closure of the gas source to the Blast
Tube (2). A Modulating Motor (3) controls the positioning of
a Modulating Butterfly Gas Valve (4) and movable Air
Dampers (5) through Mechanical Linkage (6). The gas flow
control rate is accomplished through adjustment of the
Main Gas Pressure Regulator (7) and the Butterfly Valve. A
proven spark ignited gas pilot* provides ignition for the
main flame. When the gas pilot has been proven by the
flame detector*, the Diaphragm or Motorized Gas Valve
opens and allows gas at a rate controlled by the Butterfly
Valve to go to the Blast Tube for main flame low fire light off.
After a short period of time at the low fire position, the
Modulating Motor will drive the Butterfly Valve and the Air
Dampers to the high fire position. The burner will stay at
high fire until the system pressure or temperature increases
to a selected preset point, at which time a modulating type
controller will drive the Modulating Motor to low fire, or
whatever firing position between low and high fire is
required to match the system load demand. The Modulating
Figure 20
Typical Oil Burner with On-Off Fuel/Air Control Mode
7 Nozzle
Field Piped
Inlet
1 8
4
6
Low Oil
1 Oil Solenoid
Pressure Switch **
Valves
COMBU Oil Pump 2
Filter*
Check Valve Fuel Shutoff
(At Tank)* Valve*
increase the travel of the Air Damper Arm (13) as the
Linkage Rod ball joint (11) is moved away from the Gas
Valve Crank Shaft (12). The travel of the Air Damper
Driven Arm will be increased as the Linkage Rod ball
joint (14) is moved toward the Air Damper Axle Shaft (15).
When adjusting linkage travel, make certain that the
driven arm Linkage Return Iron Weight (16) does not
interfere with the Linkage operation - and that all linkage
components are free from binding.
*
Note 1
Component operational sequencing will vary with the specific
Flame Safeguard Control being used. Refer to the specific
Flame Safeguard Control bulletin supplied with the burner for
complete information.
2 3
5
Motor will continually reposition the firing rate in an effort to
exactly match system load demand. Blast Tube gas pres-
sures can be taken at the
between the Butterfly Valve and the gas Blast Tube. Refer to
the Burner Specification computer printout supplied with
the burner, for specific high fire gas pressure values. When
the system pressure or temperature cutoff point is reached,
the Diaphragm or Motorized Gas Valve closes (normally
the burner will be at the full low fire position at this time) and
the Air Dampers will go to the low fire light off position in
preparation for the next firing cycle. This depiction shows
the Linkage in the low fire light off position. Refer to page
22, Figure 27 for information on linkage adjustments. Also
see page 22 for information on the Varicam
characterized fuel metering system.
*
Note 1
Component operational sequencing will vary with specific
Flame Safeguard Control being used. Refer to the specific
Flame Safeguard Control bulletin supplied with the burner for
complete information.
Pressure Gauge
Vacuum Gauge Port
Test Port 6
Optional Inlet Ports
Nozzle Port Oil
Pump
Side
View
Return
Inlet Port
Vent Ports
Port
Fusible Link Valve Check
(If Required by Code)* Valve*
Not shown in this depiction. See page 4, Figure 2.
1 / " Plugged Test Port (8) located
4
Not shown in this diagram. See page 4, Figure 3.
*
Vacuum Gauge Port
** Burners with Remote Pressure
3 / " Allen Screw
5
32
For Oil Nozzle
CAUTION:
Pressure
All field piped components must be
Adjustment mounted in the proper location and
proper direction of oil flow.
CAUTION:
Return
Oil supply pressure to Burner Pump
To Tank
must not exceed 3 PSI per NFPA Code.
Field
Piped DO NOT USE TEFLON TAPE
TM modulating
By Others Unless Specified
on Order.
Atomizing Oil Pumps require a
Low Oil Pressure Switch.