Midco G69B User Manual
INSTALLATION AND
SERVICE INSTRUCTIONS
UNIPOWER
G56B G57B
G58B G69B
Power Burners
In the United States, Installation must conform with local
codes or , in the absence of local codes, with the National
Fuel Gas Code, ANSI Z223.1-latest edition available from
American National Standard Institute. Further reference
should be made to the recommendation of your fuel
supplier.
In Canada, Installation must conform with local codes or, in
the absence of local codes, with Installation Codes for Gas
Burning Appliances and Equipment, CGA Standard
CAN/CGA 1-B-149.1 or 2. When the conversion burner
burner is used on a Forced Air Central Furnace, the two
yellow and black warning labels in the literature envelope
shall be attached in accordance with Installation Code,
CGA Standard CAN/CGA 1-B149, Clause 5.4.4.4. Further
reference should be made to the recommendation of your
fuel supplier.
WARNING: Additions, changes, conversions, and
service must be performed by an authorized MIDCO
representative, service agency, or the fuel supplier. Use
only MIDCO specified and approved parts.
INSTALLER: Inform and demonstrate to
the user the correct operation and
maintenance of the gas utilization
equipment. Inform the user of the
hazards of storing flammable liquids
and vapors in the vicinity of this gas
utilization equipment and remove
such hazards. Affix this manual
and associated literature to the
WARNING: If the information in these
instructions is not followed exactly, a fire or
explosion may result, causing property
damage, personal injury or death.
Do not store or use gasoline or other
flammable vapors and liquids in the vicinity
of this or any other appliance.
WHAT TO DO IF YOU SMELL GAS
Do not try to light any appliance.
¥
Do not touch any electrical switch;
¥
do no use any phone in the building.
Immediately call your gas supplier from
¥
another buildingÕs phone. Follow the gas
supplierÕs instructions.
If you cannot reach your gas suppler, call
¥
the fire department.
Installation and service must be performed
by a qualifed installer, service agency or
the gas supplier.
BURNER
MODEL
BILL OF MATÕL
NUMBER
DATE CODE
WIRING
DIAGRAM
FOR SERVICE CONTACT:
name
address
conversion burner.
CODE COMPLIANCE IS THE SOLE
RESPONSIBILITY OF THE INSTALLER.
phone
USER: Retain this manual for future reference. If other than routine service or
maintenance as described in this manual and associated literature is required,
contact a qualified service agency. DO NOT ATTEMPT REPAIRS. An inadvertent
service error could result in a dangerous condition.
SAFETY INFORMATION TERMS: The following terms are used to identify hazards, safety precautions or special notations and
have standard meanings throughout this manual. When you see the safety alert symbol and one of the safety information terms,
as shown below, be aware of the hazard potential.
DANGER: Identifies the most serious hazards which will result in severe personal injury or death.
WARNING: Signifies a hazard that could result in personal injury or death.
CAUTION: Identifies unsafe practices which would result in minor personal injury or product and property damage.
MIDCO
International Inc.
4140 WEST VICTORIA STREET ¥ CHICAGO, ILLINOIS 60646 ¥ (773) 604-8700 FAX: (773) 604-4070 ¥ http://www.midco-intl.com
PRINTED IN U.S.A.
8470-86
598
SPECIFICATIONS
BURNER STYLE...................................................................... Power Type
PILOT TYPE............................................................................. Intermittent, Spark Ignition
PILOT SAFETY........................................................................ Instantaneous Electronic Flame Safeguard
STANDARD VOLTAGE
CONTROLS (FIELD WIRING)...............................................120/1/60
MOTOR................................................................................. 115/1/60 (except G69B-115/230/1/60)
U.L. LISTED
NATURAL Gas
(1,000
BTU/cu. ft.)
G56B
G57B
G58B
G69B
MODEL BURNER MANIFOLD
PROPANE Gas
(2,500
BTU/cu. ft.)
G56BP
G57BP
G58BP
G69BP
Maximum
1
Input
MBTU/Hr.*
1000
1450
1800
2500
Maximum
Air
SCFM
224
313
385
521
INLET GAS PRESSURE
REQUIRED
6
NATURAL
5.0" W.C.
7.0" W.C.
6.7" W.C.
7.5" W.C.
2
PROPANE
5.0" W.C.
5.0" W.C.
6.0" W.C.
8.0" W.C.
PRESSURE
NATURAL
2.2" W.C.
4.1" W.C.
4.6" W.C.
4.2" W.C.
1, 4, 5
PROPANE
1.2" W.C.
2.6" W.C.
3.8" W.C.
3.3" W.C.
Minimum Input
MBTU/Hr.*
300
300
500
800
3
Motor HP
(3450 RPM)
1/6
1/3
1/2
3/4
Recom-
mended
Combustion
Chamber Size
42" x 18"
48" x 21"
50" x 24"
60" x 27"
TABLE 1 Burner Specifications
1. Values given based on +0.000" W.C. firebox pressure, altitudes to 2000 feet. Derate burner for altitudes over 2000
feet by 4% for each 1000 feet over sea level.
2. Maximum inlet pressure both gases: 14" W.C. Refer to Section VI Piping for high pressure.
3. Modulating and two-step burners are limited to a 3 to 1 turndown ratio.
4. Manifold pressures are approximate and will vary slightly according to job condition. See Section VII para. 11.
5. Pressures are based on 25% excess combustion air.
6. SCFM = Standard Cubic Feet/Minute.
MAXIMUM CAPACITY IN MBH AT
* 1 MBH = 1,000 BTU/Hr.
MODEL
G56B
G57B
G58B
G69B
MINIMUM
FIRING RATE
MBH*
300
300
500
800
COMB. CH. - BACK PRESSURE
0" W.C.
1075
1500
1850
2500
.25" W.C.
950
1400
1750
2375
.5" W.C.
875
1325
1650
2275
TABLE 2 Maximum Capacity at Specified Back Pressures
MAXIMUM BACK
PRESSURE
IN " W.C.
0.7
0.8
1.0
1.0
MAXIMUM MBH* @
MAX. B.P.
700
1325
1400
2100
PART 1 INSTALLATION
CAUTION: Unipower GB -Series are not intended
for outdoor installation and must be protected from
excessive moisture. Provide adequate clearance for
service and proper operation.
I VENTILATION
Open basements will generally allow sufficient air
infiltration, so special provisions will seldom be required. If
the heating plant is located in a separate furnace room or
in an unusually tight basement, permanent means must be
provided to supply an ample volume of fresh air for
combustion and boiler room ventilation. A direct opening
to the outside air should be provided sized on the basis of
1/2 square foot of free opening for each 1,000,000 BTU of
burner rating when the vent connector is equipped with a
barometric draft control, 1 1/2 square feet when equipped
with a draft hood. If the ventilation opening is screened, it
should be of 1-1/4" mesh. The opening should be located
at least six feet over ground level to prevent accidental
obstruction. If a direct opening to the outside air is not
available, an ample sized air duct can be run to the
nearest outside air source; or, if practical, open stairwells
or building corridors connecting to an outside wall having a
ventilating opening can be used for this purpose, provided
that no possibility of accidental closure exists.
While the spark ignition pilot system performs successfully
under moderate or momentary back draft conditions, it is
not intended for operation under sustained reverse draft,
for example in a building with large ventilating fans but with
insufficient make-up air. Even if burner operation is
successful this condition must be corrected to prevent the
hazard of drawing flue gases into the building.
Consult your local gas company when doubt exists
concerning boiler room ventilation.
-2-
II GAS UTILIZATION EQUIPMENT
The heating system, both the gas utilization equipment
and the distribution system, should be in good repair and
sufficient to properly heat the building. It should be
determined if any serious faults are present that would
cause excessive fuel consumption, unsafe operation or
improper heating, and measures taken to correct them.
After the grates and grate operating parts have been
removed from the firebox, the boiler interior should be
thoroughly cleaned, removing all adhering dirt, tars,
scale and soot. All joints should be cemented to prevent
excess air infiltration into the boiler. Clean out doors
should be checked for close fit, and sealed with furnace
cement if they fit poorly.
Firing door catches should be filed off or otherwise
arranged so that the door will open easily to relieve
pressure. No positive catches should be used. The use
of a spring type door holder is recommended.
III COMBUSTION CHAMBER
The UNIPOWER gas burner is designed for "in-shot"
firing. It can be fired into the ashpit of a boiler designed
for solid fuels, or it can be fired into the primary heat
exchanger of a boiler designed for liquid or gaseous
fuels. The ashpit installation requires a refractory lining.
The combustion chamber serves to contain and promote
combustion and to protect non-heat exchange surfaces
from direct flame contact. Built-up combustion chambers
should be made of 2600
alternative, a monolithic floor can be cast in place, using
a high temperature (2400o), light weight insulating
refractory. Check with your supplier to determine the
thickness which will yield equivalent insulating qualities.
The top of the combustion chamber should be positioned
2 to 6" above the base of the heat exchanger. If the
combustion chamber is to be set directly on the floor,
provide a minimum of 1/2" insulating millboard or
magnesia block underlay for floor protection. Use high
temperature fill such as vermiculite in voids around the
combustion chamber. Any portion of the heat exchanger
not exposed to circulating air or water should be covered
with insulating firebrick.
The combustion chamber sizes given in Table 1 are
based on the maximum rated burner capacity. If the
input is to be permanently set at a reduced rate the
combustion chamber floor area can be reduced
proportionately to the proposed input, with the length as
closely proportioned to twice the width as possible.
Where recommended size combustion chambers
(225,000 BTU/sq. ft.) can be accommodated, the type of
construction shown in Figure 1 should be used. If lack of
space prohibits use of this construction, higher BTU
values per square foot can be allowed for by using the
constructions shown in Figure 2 and 3.
The back wall of the combustion chamber should be
carried 2 or 3 courses higher and overhung to deflect the
flames from direct impingement on the rear heat
exchanger surface. Hard firebrick should be used to
prevent erosion of the brick by high velocity gases.
o
insulting firebrick. As an
FIGURE 1 Typical Floor And Wall Construction For
225,000 BTU Per Square Foot. (Standard)
FIGURE 2 Typical Floor And Wall Construction For
275,000 BTU Per Square Foot.
FIGURE 3 Typical Floor And Wall Construction For
350,000 BTU Per Square Foot. (Maximum)
The burner is equipped with a mounting flange for direct
attachment to the boiler front, and mounting brackets for
legs. Use both if necessary for rigid installation. The
burner nozzle must not extend into the combustion
chamber. It should be sealed into the opening as shown
in Figure 4.
WARNING: BURNER CABINET MUST BE
MOUNTED IN ORIENTATION IN FIGURES 4 AND 7.
ANY OTHER MOUNTINGS MAY CAUSE A
DANGEROUS CONDITION, AND WILL VOID BURNER
WARRANTY AND AGENCY APPROVALS.
NON-STANDARD ARRANGEMENTS MAY BE
AVAILABLE FOR SOME MODELS-CONSULT
FACTORY FOR DETAILS IF REQUIRED.
-3-
FIGURE 4 Construction at Burner Entrance
The refractory lined combustion chamber can be omitted in
"Scotch Marine" and "Steam Generator" boilers or warm
air furnaces that include no ashpits. The burner is fired
directly into the heat exchanger, requiring no refractory
unless the combustion chamber is so short that flame
would impinge excessively on the rear heat exchanger wall
(this particularly important in a warm air furnace).
Refractory protection is recommended if the length of the
primary chamber is less than 20% larger than the length
given in Table 1. In any case, the burner entry wall must
be refractory lined if it is not a heat exchanger surface.
Firing Door Installations
It is advantageous, on occasion, to fire through the boiler
firing door. For example, pitting can be avoided on low
base boilers, damage to the burner can be avoided if
basement flooding is prevalent, or the combustion
chamber volume can be reduced in boilers with unusually
large ashpits.
Great care in planning will be required for firing door
applications since flame impingement on boiler surfaces is
more probable. Do not fire a boiler which contains a drop
section directly in the path of the flame, or do not fire over
a water grate in a smokeless type boiler. The firebox
length must be great enough to exceed the combustion
chamber lengths given in Table 1 by at least 20%.
When raising the floor, maintain sufficient firebox volume
to limit the heat release to 50,000 BTU per hour per cubic
foot or less. Use the entire floor as a combustion chamber
a and cover the water leg base to 6" from the bottom. Floor
construction should conform to Figures 1 to 3.
Firing door installations will usually entail removal of the
grates. Figure 8 shows a typical installation. A steel plate
floor can be supported from the grate lugs, if suitable. In
any case, the floor must be rigid enough to prevent
sagging, being supported by brick piers as necessary.
If firing over the grate, level it off with rubble of common
brick or firebrick if necessary; then cover over with
insulating block before laying the refractory floor.
The hearth of worm feed stokers can be used as a floor
base. Level off the hearth to a suitable height, remove the
worm feed mechanism and fill the tuyere with rubble.
Cover at least the tuyere area with block insulation; if using
castable refractory, pour a new floor over a leveling
surface of sand. The external stoker parts should be
removed to eliminate clutter under the burner.
The burner mounting in the door must be rigid and
refractory lined as shown in Figure 8. The burner nozzle
must not protrude directly into the combustion chamber.
The refractory liner must extend beyond or be flush with
the burner face as shown in Figure 4. A sheet metal rim
should encase the refractory up to the inside of the boiler
wall. It should be intermittently bent inward to retain the
refractory, or other means of anchoring should be
provided.
FIGURE 5 Conventional BoilerÑ Small Firebox
FIGURE 7 Tubular Combustion Chambers
FIGURE 6 Conventional BoilerÑLarge Firebox
-4-
Loading...