Eclipse RatioMatic 50 User Manual page 5

1
Control Motor
Rotates air valve:
Open for more heat
Closed for less heat
Pilot
Adjusting
Valve
Set-Up & Operation
Against a Draft
(Negative Chamber Pressure)
120
100
Excess Air
80
60
40
20
0
Low Fire
Air Valve Settings:
• Factory Set–fully open at high fire, fully closed
at low fire.
Results:
• High fire is increased.
• Low fire is increased.
• Turndown ratio is unaffected.
• To reduce high fire, use an end limit switch
to reduce motor travel.
Figure 2–Ratiomatic Operation
Main Gas
Adjusting
Valve
Loading Line
Transmits air pressure
changes to Ratio Regulator
Set-Up & Operation
OR
(Neutral Chamber Pressure)
120
100
80
60
40
20
0
High Fire Low Fire
Air Valve Settings:
• Factory Set–fully open at high fire, fully closed
at low fire.
Results:
• Normal high fire.
• Normal low fire.
• Normal turndown.
Air Valve
2
OR
Excess Air
High Fire
Air Valve Settings:
• Factory Set–fully open at high fire, fully closed
Results:
• High fire is increased.
• Low fire is normal.
• Turndown ratio is decreased.
• To limit air valve overtravel at high fire, use an
5
Low Fire
Gas Adjustment
Factory set for most applications;
can be field adjusted if necessary.
3
Proportionator
Changes gas flow
in proportion to
loading line pressure;
Higher pressure = more gas
Lower pressure = less gas
Set-Up & Operation
Against Back Pressure
(Positive Chamber Pressure)
120
100
80
60
40
Excess Air
20
0
Low Fire
at low fire.
end limit switch to reduce motor travel.
High Fire