Midco E20BP - Manual (Page 2)

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FIGURE 1 Dry Base Boiler with Combustion Chamber
Liner (Furnace Construction is Similar)
SPECIFICATIONS
Model E20B -- NATURAL Gas Only
Model E20BP -- PROPANE Gas*
AIR DELIVERY (Approximate Air
Delivery at Zero Draft)................................. 47 SCFM**
MAXIMUM FIRING RATE***.............................225 MBH****
MINIMUM FIRING RATE***................................50 MBH****
TUBE DIAMETER....................................................4 inches
TUBE LENGTH........................................................8 inches
MINIMUM COMBUSTION CHAMBER SIZE
225 MBH.......................................7" W x 11" L or 10" dia.
150 MBH.........................................6" W x 10" L or 9" dia.
GAS PRESSURE REQUIRED:
NATURAL and PROPANE....................5.0" to 14.0" W.C.
STANDARD VOLTAGE....................120 volts..........60 cycle
PILOT SAFETY......................Thermoelectric, 100% shut-off
* Model E20BP is equipped with a Redundant Main
Automatic Valve.
** SCFM = Standard Cubic Feet/Minute
*** Ratings based on 1000 BTU/cu. ft. NATURAL, 2500
BTU/cu. ft. PROPANE at Sea Level.
**** 1 MBH = 1,000 BTU/hr.
One gallon of fuel oil = 140,000 BTU.
Derate burner for altitudes over 2,000 feet by 4% for each
1,000 feet of addition elevation
PART 1 INSTALLATION
CAUTION: The ECONOMITE E20B(P) is not in-
tended for outdoor installation and must be protect-
ed from excessive moisture. Provide adequate
clearance for service and proper operation.
I VENTILATION
If the former automatic oil burner gave trouble-free operation, it
is probable that the gas utilization equipment area has
sufficient infiltration of air for combustion and dilution of flue
gases. Nevertheless, the area must be checked.
■ Open basement or utility areas of normal construction,
without storm windows or tight doors, will generally allow
sufficient air infiltration. However, if the gas utilization
equipment is located in a tight or separate room, ventilation to
an open area as described above will be required. Install two
permanently open grilles, each sized on the basis of one
square inch free area per 1,000 BTU (but not less than 100
square inches) of the total input rating of all gas utilization
equipment in the confined space. One grille should be located
within 12 inches of the ceiling, the other within 12 inches of the
floor.
■ If the gas utilization equipment is located in an area of
unusually tight construction, or if an exhaust fan, kitchen
ventilation system, clothes dryer and/or fireplace is installed in
the building, provision must be made for an outside air supply
near the gas utilization equipment area. Install permanently
open grilles sized at not less than one square inch free area
per 4,000 BTU of total input. When ventilating through
horizontal ducts, grilles should be sized at not less than one
square inch free area per 2,000 BTU of the total input rating of
all gas utilization equipment. In the confined space in any case,
the minimum dimension of
rectangular air ducts shall not be
less than 3 inches.
■ In Canada, for detailed ventilation requirements, refer to
standard CAN/CGA 1-B149.1 or .2 and/or local codes.
II PREPARATION OF THE
HEATING APPLIANCE
■ Clean the heating appliance, heat exchanger interior,
combustion chamber and flue connections. Remove all
adhering tars, scale, dirt and soot. Inspect for actual or potential
leaks.
■ Cement all joints, including those in the heating appliance
base and around the door frames, to prevent leakage into, or
out of the combustion chamber.
■ The access or firing door should open easily to relieve
pressure. If positive latches exist, they should be modified to
permit easy opening; a spring loaded door holder is
recommended.
■ On all boilers, make certain the pressure relief safety valve is
in good operating condition.
III COMBUSTION CHAMBER
A combustion chamber liner is normally required to protect
non-heat transfer surfaces and to provide a radiant bed for
rapid heat transfer to the primary surfaces of the heat
exchanger. In most cases an existing oil burner combustion
chamber liner can be used, if in good condition.
■ In the case of wet base boilers, where the entire firing
chamber is comprised of heat exchange surfaces and no
chamber liner was provided for oil firing, a liner is usually not
required for the ECONOMITE. However, a liner or target wall
may be necessary if the firing chamber is unusually short, in
order to avoid excess flame contact on the heat exchanger
walls or flueways.
■ If a built up chamber liner is required, use 2,300oF minimum
insulating material.
■ The burner tube, or the stainless steel sleeve that is included
with the burner, must be sealed air tight into the combustion
chamber liner opening with refractory material as shown by
Figures 1 and 2. The sleeve is preferred as it is designed to
properly locate the end of the tube relative to the inside wall of
the combustion chamber, and to permit burner removal without
breaking the seal.