Datasheet
9
Eclipse RatioMatic Burner, RM Series, V5, Design Guide 110, 11/11/2011
Step 3: Control Methodology
Figure 3.4. Air : Gas Flow
All standard RatioMatic burners are designed for:
• air:gas ratio controlled combustion
• 10 - 15% excess air at high fire
• higher excess air at low fire
Burner Control
RatioMatic burners come with a ratio regulator that
maintains the air:gas ratio, see figure 3.4.
Figure 3.5. Basic Burner Components
• A control signal is sent from a process temperature
controller (sold separately) to the control motor.
(Refer to Bulletin 818C or contact Eclipse for further
information on temperature controllers.)
Figure 3.6. Basic Control Loop
• The control motor modulates the air butterfly valve
(BV) which controls the combustion air flow.
• Air pressure in the burner body sends an impulse
down the loading line to the ratio regulator.
• The ratio regulator controls the gas flow in
proportion to the air flow.
■ Do not use other control methods, such as fixed-
air control, or alter the ratio regulator or burner
piping without prior approval from Eclipse.
Step 4: Ignition System
Ignition Transformer
For the ignition system, use a transformer with:
• secondary voltage 6,000 to 8,000 VAC
• minimum secondary current 0.02 amps
• full wave output
DO NOT USE the following:
• twin outlet
• distributor type
• electronic type
Trial for Ignition
It is recommended that low fire start be used. However,
under certain circumstances RatioMatic burners are
capable of direct spark ignition at higher gas inputs.
Most local safety codes and insurance requirements limit
the maximum trial for ignition time (the time it takes for a
burner to ignite). These requirements vary from one
location to another; check your local codes and comply to
the strictest codes applicable.
The time it takes for a burner to ignite depends on the
following:
• the distance between the gas shut-off valve and the
burner
• the air:gas ratio
• the gas flow conditions at start-up
Gas
Air
Stoichiometric
R
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Excess air
Packaged
Blower
Control
Motor
Integral Air BV
Ratio
Regulator
Control
Signal
Gas Flow
Process
Set Point
Process
Controller
Control
Motor
Air
BV
Ratio
Regulator
Temperature
Pressure
Impulse
WARNING