Midco RS40 - Manual (Page 6)

?? As shipped, the installed
NATURAL gas spud has a .266"
diameter orifice size for an input
capacity range of approximately
150 to 200 MBH. Spare spuds
are included in a spare spud
bag (stamped with inch
diameter) for other capacity
ranges and/or conversion to
PROPANE, see Table 3.
?? The Combination Valve
Gas Pressure Regulator is set
to provide 2.0" W.C. manifold
gas pressure for minimum spud
input and the combustion air
shutter is set for maximum spud
input, to provide a lean gas/air
mixture for initial start up.
?? If a standard NATURAL gas
ECONOMITE RS40 is to be
used with PROPANE gas, affix
the PROPANE label from the spare spud bag over the NAT designation on the rating plate
and install the appropriate size main spud as detailed below.
?? If the required firing rate does not fall within the range of the installed spud, or if con-
verting to PROPANE gas, select the correct capacity range from Table 3 and if so indicated,
the spud with the correct orifice size (stamped with inch diameter) from the spare spud bag.
If the required firing rate is at the minimum of a capacity range, select the next lower range
spud.
?? To change the main spud, turn off the Main Manual Shut-Off Valve and burner power,
remove the backplate, disconnect the field installed union located between Combination
Valve and Main Manual Shut-Off Valve and remove manifold assembly. Remove Nozzle
Assembly from Main Gas Spud, see Figure 7.Unscrew the installed main spud from the
manifold pipe and install the selected main spud. Reassemble burner in reverse order.
WARNING: Reposition the combustion air shutter for the maximum firing rate of
the selected spud capacity range. Do not change the Combination Valve Main Gas
Pressure Regulator setting at this time.
CAUTION: The approximate air and gas settings described above are for initial
start-up only. Final settings must be made in accordance with Section VIII, Initial
StartUp/Adjustment Instructions for adjustment of the manifold gas pressure are
detailed in Section XI, Combination Gas Valve.
_____________________________________
WARNING: Ignition is automatic. Make spark observations into combustion
chamber only with Main Manual Shut-Off Valve closed. Confirm that gas utilization
equipment does not contain any accumulated gases. Purge as described in Step 3
below.
1.
Check the burner piping and valves for gas leaks by applying a weak liquid soap
solution to unions and joints with the gas supply on. Leakage will be indicated by the
appearance of soap bubbles. Locate and correct all gas leaks before proceeding.
WARNING: DO NOT USE OPEN FLAME FOR CHECKING.
2. Purging the air from the gas supply line at this step will expedite the first light-off.
CAUTION: Purge gas to outside the building. Do not purge into the gas
utilization equipment.
3.
To purge the gas utilization equipment and chimney of any accumulated gases, turn
Manual Gas Cock Knob on the Combination Valve to OFF, turn burner power on and set
the operating control to ON or thermostat to call for heat. Let the blower run long enough to
accomplish four air changes, but not less than five minutes.
4.
CAUTION: Make sure that the capacity range of the installed spud and the
preliminary combustion air shutter setting are suitable for capacity rating of the gas
utilization equipment. Refer to Section VII, Main Gas Spud and Table 3.
5.
RESET the Electronic Control by setting the operating control to OFF or the thermostat
below room temperature for at least 30 seconds, see Section XII, Electronic Control.
6.
Confirm that Main Manual Shut-Off Valve is open. Turn Manual Gas Cock Knob on
Combination Valve to ON.
VIII Initial
StartUp/Adjustment
6
VII Main Gas Spud
Continued
*Main Gas Spud Orifice Size, approximate Manifold Pressure
setting as shipped. Data shown is approximate and based
on "0" overfire pressure at sea level
Table 3: Main Gas Spud Capacity and
Preliminary Gas and Air Settings
Part 1
Installation Continued
Part 1 Installation