Patterson-Kelley MACH-05 ユーザーズマニュアル

 

Page  26 

 

 

Natural Gas 

7" W.C 

5.0 + 0.2 

9.0 + 0.2 

5.2 + 0.2 

8.8 + 0.2 

Propane 

11" W.C 

5.0 + 0.2 

10.4 + 0.3 

5.2 + 0.2 

10.3 + 0.3 

 

There must be sufficient load to operate the boiler at 
high fire to perform the following adjustments.  Start 
the boiler and observe proper operating parameters for 
the system.  
 
Note:  The MACH C300 and C450 boilers are each 
equipped with two gas safety shut off / control valves 
that operate in parallel. When making any adjustment 
to the valves, the adjustment must be performed on 
each of the valves equally.   

Example:  If an increase in the gas flow is required to 
lower the O

2

 level, turn each of the maximum flow 

restrictors equivalent amounts (i.e. ¼ or ½ turn each) 
and allow the analyzer readings to respond and 
stabilize before proceeding with additional adjustment.  
Adequate response time must be allowed for 
combustion readings to stabilize. This response time 
will be longer for low firing rates than for high firing 
rates. 
 

 

Set boiler to the “Test Mode High”, as described 
above, to achieve maximum firing rate of the boiler. 
Check combustion readings using a combustion 
analyzer.  If combustion readings are not in 
accordance with Table 3-1 adjust as follows: 

Using a slotted screw driver or 2 mm hex wrench, set 
the maximum restrictor (high fire screw – see the 
figure below, item “D”) on each of the gas safety shut 
off / control valves by turning clockwise or 
counterclockwise to achieve the desired CO

2

 or O

2

 

level; see Table 3-1 for correct settings.  (There will be 
a slight time delay between the adjustment and the 
response of the CO

2

/O

2

 measuring instrument).  

Clockwise rotation decreases gas flow.  
Counterclockwise rotation increases gas flow. 

Set boiler to the “Test Mode Low”, as described 
above, to achieve minimum firing rate of the boiler. 
Check combustion readings using a combustion 
analyzer.  If combustion readings are not in 
accordance with Table 3-1 adjust as follows: 

Using a 2 mm hex wrench, adjust the pressure 
regulator offset adjustment (see the figure below, item 
“R”) to achieve the CO

2

 /O

2

 level prescribed in Table 

3-1.  Note that equal adjustments must be made to 
each of the valves.  Adjustments to the offset pressure 
regulators should not exceed ¼ turn at a time before 
allowing the readings to respond and stabilize.  Please 
note, the rotation of the Low Fire adjustment is 
opposite of the High Fire as follows: Clockwise 
rotation increases gas flow, counterclockwise rotation 
decreases gas flow. 
 

"R" 

 

"D"