Page 1
Replacement Parts
List
• First Construction October 1976; date code 4176 (41st week, 1976).
• Push-Pull Input Adjusters fi rst used June 1980; date code 2380 (23rd week, 1980).
Unipower G series
Installation and Service Manual - 8449-06
Date Code - April 2000
• Push-Pull Input Adjusters discontinued approximately June 1989; date code 2489 (24th week, 1989)-See Note 5.
AVOID ERROR IN PARTS SELECTION. When ordering use complete MIDCO Part Number and Description. Furnish
Midco® International Inc.
4140 West Victoria Street
Chicago, Illinois 60646
toll free 866.705.0514
tel 773.604.8700
fax 773.604.4070
web www.midcointernational.com
e-mail sales@midcointernational.com
Burner Model Number, Bill of Material Number and Serial Number (if available) from the specifi cation plate found on the
product.
IMPORTANT: Availability of parts as well as specifi cations are subject to change without notice. Please consult factory for
item availability.
Quality Designed for Proven Performance
713
8472 00
Printed in USA
Page 2
Exploded View - G Series
41
44
43
42
40
39
38
2
1
5
6
7
3
4
8
11
10
9
13
12
14
15
16
37
23
36
35
24
34
33
32
25
31
22
26
30
27
21
28
29
19
20
13
18
17
Item Part # Description N/S = Not Shown Item Part # Description N/S = Not Shown
WIRING BASE (See Note # 8 )
1A 8429-16 Q7800B Sub-Base for RM7895
1B 8428-42 Fireye M Base
CHASSIS (Order plug-in components separately)
2A 8429-19 RM7895A 1048 Controller
2B 8429-17 RM7840M 1017 Controller
2C 8429-34 RM7895C 1012 Controller
PLUG-IN PURGE TIMER (see note # 4 & # 8)
3A 8429-22 ST7800 for RM7895 30 seconds
3B 8429-25 ST7800 for RM7895 90 seconds
PLUG-IN AMPLIFIER
4 8429-27 R7847A Rect Amplifi er
PILOT SHUT OFF VALVE
5 8483-01 1/8″ M X 5/16 T Compression Elbow
6 8402-00 Gas Safety Shut-Off Valve-1/8″ NPT; 120/1/60
7 8483-30 5/16″ O.D. Tube X 1/8″ NPTM Straight Fitting
2
Midco International Inc.
8472 00
Page 3
Parts List
Item Part # Description N/S = Not ShownItem Part # Description N/S = Not Shown
MOTOR MOUNTING PLATE
8 3197-50 Motor Mounting Plate—Used on 56C or 66C
Frames (ref. Models G57, G58 & G69. Became
production item on G56 Models approximately
July 1989).
BLOWER MOTORS - 1-Phase, 48M of J48Y Frame
(3450 RPM, 1/2″ Shaft) Open Drip Proof
9A 6728-90 G56 1/6 HP 115/230/1/60/50
9B 8437-31 G57 1/3 HP 115/230/1/60
9C 8437-15 G58 1/2 HP 115/230/1/60
9D 8437-25 G69 3/4 HP 115/230/1/60
BLOWER MOTORS - 3-Phase, 56C Frame (3450 RPM,
5/8″ Shaft)
9E 8440-19 G58 1/2 HP 20/230/460/3/60 TENV Motor
9F 8440-20 G69 3/4 HP 208/230/460/3/60 TENV Motor
BLOWER WHEELS
10A 6748-00 G56 5-1/4″ dia x 3-1/2″ W (1/2″ Bore)
10B 3427-50 G57 6-5/16″ dia x 4″ W (5/8″ Bore)
10C 3627-50 G58 & G69-7″ dia x 3-1/2″ W (5/8″ Bore)
MAIN GAS TRAIN COMPONENT -
V48A DIAPHRAGM VALVES
11A 8418-21 1″ V48A Diaphragm Valve
11B 8418-22 1-1/4″ V48A Diaphragm Valve
11C 8418-23 1-1/2″ V48A Diaphragm Valve
11D 8418-20 2″ V48A Diaphragm Valve
11E 8418-41 2-1/2″ V48A Diaphragm Valve
MAIN GAS TRAIN COMPONENT - On-Off or Full Mod
MOTORIZED VALVE BODY -
V5055A without “Proof of Closure” Switch
N/S 8418-32 1″
N/S 8418-33 1-1/4″
N/S 8418-34 1-1/2″
N/S 8418-35 2″
N/S 8418-36 2-1/2″
MAIN GAS TRAIN COMPONENT - On-Off or Full Mod
MOTORIZED VALVE BODY -
V5055C with “Proof of Closure” Switch
N/S 8418-90 1″
N/S 8418-91 1-1/4″
N/S 8418-92 1-1/2″
N/S 8418-93 2″
N/S 8418-94 2-1/2″
MAIN GAS TRAIN COMPONENT - On-Off or Hi Lo Off
POSITIVE LOW FIRE START -
V5055B without “Proof of Closure” Switch
N/S 8418-78 1″
N/S 8418-84 1-1/4″
N/S 8419-00 1-1/2″
N/S 8419-01 2″
MAIN GAS TRAIN COMPONENT -
MOTORIZED VALVE ACTUATOR
N/S 8418-31 V4055A On-Off w/out “Proof of Closure” Switch
N/S 8418-88 V4055D On-Off with “Proof of Closure” Switch
N/S 8418-79 V4062A Hi-Lo-Off Low Fire Start
N/S 8418-97 V4062D Hi-Lo-Off Low Fire Start with “Proof of
Closure” Switch
MAIN GAS TRAIN COMPONENT -
SOLENOID VALVES
Vent Valves (normally open)
N/S 8402-30 3/4″ Solenoid Valves (normally open)
N/S 8402-31 1″ Solenoid Valves (normally open)
MAIN GAS TRAIN COMPONENT -
PRESSURE REGULATORS - Maxitrol RV Series
12A 8416-33 RV61 1″ Maxitrol Gas Pressure Regulator
12B 8416-02 RV61 1-1/4″ Maxitrol Gas Pressure Regulator
12C 8416-05 RV81 1-1/2″ Maxitrol Gas Pressure Regulator
12D 8416-08 RV91 2″ Maxitrol Gas Pressure Regulator
12E 8416-11 RV111 2-1/2″ Maxitrol Gas Pressure Regulator
MAIN GAS TRAIN COMPONENT -
BALL VALVES - Side Taps
13A 8404-23 1″ NPT Ball Valve with Side Tap
13B 8404-24 1-1/4″ NPT Ball Valve with Side Tap
13C 8404-25 1-1/2″ NPT Ball Valve with Side Tap
13D 8404-26 2″ NPT Ball Valve with Side Tap
MAIN GAS TRAIN COMPONENT -
REGULATOR/COCK KITS
14A 6773-60 Regulator/Cock Kit 1″
14B 6773-00 Regulator/Cock Kit 1-1/4″
14C 6773-10 Regulator/Cock Kit 1-1/2″
14D 6773-20 Regulator/Cock Kit 2″
8472 00
Midco International Inc.
3
Page 4
Exploded View
Item Part # Description N/S = Not ShownItem Part # Description N/S = Not Shown
MAIN GAS TRAIN COMPONENT -
SAFETY VALVES (Normally closed)
15A 8418-03 1″ Solenoid Valve
15B 8402-06 1-1/4″ Solenoid Valve
15C 8402-07 1-1/2″ Solenoid Valve
15D 8402-18 2″ Solenoid Valve
15E 8402-19 2-1/2″ Solenoid Valve
FIRING RATE CONTROLS -
BUTTERFLY VALVES (see note # 5)
16A 2933-50 On-Off Butterfl y Valve Assembly 1″
16B 2933-51 On-Off Butterfl y Valve Assembly 1-1/4″
16C 2933-52 On-Off Butterfl y Valve Assembly 1-1/2″
16D 2933-53 On-Off Butterfl y Valve Assembly 2″
FIRING RATE CONTROLS -
MOTORIZED BUTTERFLY VALVES
(Contains Modutrol Motor Mounting Plate,
Overrunning Linkage and Stop Arm)
N/S 2010200 1″
N/S 2010300 1-1/4″
N/S 2010400 1-1/2″
N/S 2010500 2″
FIRING RATE CONTROLS -
MODUTROL MOTORS - (see note # 7)
N/S 8414-21 M9484D Full Modulating (no End Switch)
N/S 8414-22 Q7230A 4-20 mA Control Module for use with
M9484
N/S 8414-19 M9484F Full Modulating with Two End
Switches
N/S 8415-24 MH 198162EA 24V Transformer for use with
M9484
N/S 8414-25 M9484E Full Modulating with One End Switch
BURNER CHASSIS
17A 6712-05 Flame Retention Plate 5″ w/ Mounting
Screws—Models G56, G57 & G58
17B 6712-12 Flame Retention Plate 4.9″ w/ Mounting.
Screws used on OEM models consult factory
for applications
17C 6713-05 Flame Retention Plate 6″ w/ Mounting Screws
-- Model G69
BURNER CHASSIS - NOZZLES
18A 6735-50 Manifold Weldment (5x1) Nozzle - G56 and
G57 Nat & LP Gas and G58 LP Gas
18B 6735-00 Manifold Weldment (5x2) Nozzle G58 Nat Gas
18C 6740-00 Manifold Weldment (6x2) Nozzle G69 Nat Gas
18D 6740-05 Manifold Weldment (6x1) Nozzle G69 LP Gas
BURNER CHASSIS - SLEEVES & FLANGES
19A 6736-00 Adj Alloy 5″x5″ Sleeve- G56, G57 & G58
19B 6741-00 Adj Alloy 6″ Sleeve- G69
20A 2020300 5″ Mounting Flange Kit G56,G57 & G58
20B 2020800 6″ Mounting Flange Kit G69
BURNER CHASSIS - DRAWER ASSEMBLIES
6755-10 Drawer Assembly with Pilot and Vent Tube.
21A
Vent Tube is required when burner is equipped
with a V48A Diaphragm Type Main Gas Valve.
Order Pilot Gas and Air Orifi ces separately.
21B 6755-11 Drawer Assembly with Pilot. Order Pilot Gas
and Air Orifi ces Separately. Used on All UL
Burners with Motorized Valve.
21C 6755-13 Drawer Assembly with Pilot. Used on all CUL
Burners with V48A Diaphragm Type Main Gas
Valve Order Pilot Gas and Air Orifi ces
separately.
PILOT COMPONENTS and ACCESSORIES
22A 8447-22 Ignition Trans 120/1/60 12,000 V Secondary -
Honeywell Q652B
22B 8447-11 Ignition Transformer -- 120/1/60; 6000 V
Secondary - Allanson 1092-S
23 6729-91 Pilot Air Tube-Blower Housing to Drawer
Assembly
24 8483-35 1/4″ Bulk Head Union
25 8409-10 Silicone Boot- Orange- for covering Spark
Cable to Rod Connection
26 6764-00 Sealing Gland Nut Kit - Spark Rod Retainer
Assembly with O-Ring Seal - (
27 8432-07 Spark Rod Retainer O-Rings ONLY
28 6725-50 Spark Rod and Insulator Assembly
29 6747-00 Vent Tube (Used w/ Diaphragm Gas Valves)
30A 6725-90 Pilot with Flamerod and Spark Rod Assemblies
mounted. All UL burners with Diaphragm Valve
and all CUL burners with Motorized Valve.
30B 6725-91 Pilot with Flamerod and Spark Rod Assemblies
mounted. All UL burners with Motorized Valve
see note #1)
4
Midco International Inc.
8472 00
Page 5
30C 6725-92 Pilot with Flamerod and Spark Rod Assemblies
mounted. All CUL burners with Diaphragm
valve.
31 6720-90 Mounting Clamp for Flamerod Assembly
32 6717-00 Flamerod and Insulator Assembly
33 8483-33 1/4 MPT X 3/8 Tube Str. Connector
DRAWER ASSEMBLY COMPONENT
34 8484-72 Strain Relief SR-4K-1 Straight
35 7122-90 Peep Sight Assemby w/ Gasket & Mounting
Screws
36 5616-90 Strain Relief Bushing for Spark Cable
N/S 6717-90 Flamerod Wire Replacement Kit
N/S 8502-05 Spark Cable
TEE KITS ** Straight Kits Not Available
37A 6766-00 Nat G56 gas #60 Dr. (.040), air #26 Dr. (.147)
37B 6766-01 Nat G57 gas #60 Dr. (.040), air #30 Dr. (.128)
37C 6766-02 Nat G58 gas #55 Dr. (.052), air #26 Dr. (.147)
37C 6766-02 Nat G69 gas #55 Dr. (.052), air #26 Dr. (.147)
37D 6766-05 Prop G56 gas #64 Dr. (.036), air #26 Dr. (.147)
37E 6766-06 Prop G57 gas #64 Dr. (.036), air #30 Dr. (.128)
37F 6766-07 Prop G58 gas #56 Dr. (.046), air #26 Dr. (.147)
37F 6766-07 Prop G69 gas #56 Dr. (.046), air #26 Dr. (.147)
Parts List
Item Part # Description N/S = Not ShownItem Part # Description N/S = Not Shown
TERMINAL STRIPS
43 8408-42 10 Terminal Strip
44 8408-78 3 Terminal Strip
MISCELLANEOUS REPLACEMENT PARTS FOR
FIRING RATE CONTROL
MBF VALVE (Motorized Butterfl y Valve)
SRBF VALVE (Spring Return Butterfl y Valve--
Valve Actuator Operated)
N/S 2926-50 Overrunning Spring and Rod Assembly -- 1″
through 1-1/2″ MBF Valve
N/S 2926-55 Overrunning Spring and Rod Assembly -- 2″
N/S 2926-00 MBF Overrunning Spring
N/S 2919-01 Stop Arm for MBF Valve
N/S 7180-30 SRBF Return Spring
N/S 8414-03 Crank Arm -- Mod. Motor or Valve Actuator
Shaft
N/S 8450-94 Crank Arm -- Air Shutter and MBF Valve Shafts
N/S 7180-20 Connecting Rod -- Air Shutter to MBF Valve or
Valve Actuator
N/S 8450-18 Connecting Rod Ball Joint
N/S 8432-02 3/8″ diameter O-Ring for BF Valves and
MBF Valves
BLOWER HOUSING
38 6724-10 Blower Inlet Screen
39A 6755-50 Air Shutter—Models G56 & G57
39B 3246-08 Air Shutter—Models G58 & G69
40 6734-00 Air Shutter Shaft
41 3152-01 Quadrant—for Air Shutter Adjustment
N/S 8400-10 Pilot Pressure Regulator, 1/4” Natural and
Propane (1/2 PSI maximum inlet pressure)
FLAME SAFEGUARD and ACCESSORIES
OTHER CONTROLS
42A 8425-19 Blower Air Switch (Chicago Safety Prod. #SMP;
Tri-delta #FP4039)
42B 8425-22 Blower Air Switch Canadian Versions
N/S 8406-68 DPST Relay (Aromat: JH2A-W-AC120V- Q,
Potter Brumfi eld: T9S7A22-120)
N/S 8425-42 High Gas Pressure Switch (note # 3)
N/S 8425-43 Low Gas Pressure Switch (see note # 3)
N/S 8423-03 On-Off Toggle Switch (CH7500K14)
N/S 6765-95 High-Low Single Body Gas Pressure Switch
(note # 2)
N/S 8406-38 R4222D DPDT Switching Relay
8472 00
Midco International Inc.
5
Page 6
Unipower G Series Parts Lists
NOTES
1. Starting in July 1980 (Date Code 3080), the one piece Spark Rod Assembly Retainer was superseded by a three piece
Retainer Assembly which features an O-Ring seal to compensate for any irregularities in the Spark Rod size or shape.
When replacing the Spark Rod, the O-Ring and the one piece Retainer (on burners where it is still in use) should also be
replaced.
2. The Chicago Safety Products single body High-Low Gas Pressure Switch, Model HLGP, used through June 22, 1981
(Date Code 2681), has been superseded by an assembly of individual high and low pressure switches mounted on a
junction box. For replacement of the single body High-Low Switch, order Kit Number 6765-95, which includes 8449-88
Installation Bulletin.
3. Replacement individual High or Low Gas Pressure Switches may be a different make and have a different physical
confi guration than that previously supplied, but the mounting and wiring will be the same. Request Bulletin 8449-88 for
terminal identifi cation.
4. 30-second minimum pre-ignition purge is used with On-Off burners having the blower air shutter locked in a “fi xed”
fi ring rate position. Where the air shutter position is automatically controlled, a 90-second minimum purge or a purge with
the air shutter driven to the “high fi re” position, is required. Failure to keep pre-purge at its intended timing will VOID the
UL listing.
5. Replacement of the unavailable Push-Pull Input Adjusters can be accomplished by substituting a butterfl y valve
assembly. The BF assembly is a straight line design, whereas the Push-Pull is a right angle design. This will require
further replacement adjustments, as valve train pipe fi ttings will have to be rearranged. Be sure to carry out the same
general arrangement: BF assembly between Automatic Safety Valve and burner chassis.
6. Three Phase Arrow-Hart (A-H) Motor Starters and accessories no longer available from MIDCO. Obtain locally.
7. Honeywell discontinued manufacturing their M941 series Modulating Motors mid 1992. MIDCO stock ran out late
1992 when MIDCO switched to Honeywell M9484 Series Motors. The newer M9484 Motors are physically shorter and
require an Adaptor Bracket to mount to MIDCO MBF valves. The replacement Mod Motors shown in listing include
the necessary Adaptor Bracket. The accessory items used on the newer M9484 Motors and the 24V Transformers are
NOT interchangeable with the older M941 Motors. If exact replacements are required for the M941 Motor, consult your
local Honeywell distributor for available Tradeline replacement. When ordering 4-20 MA Control Module, Honeywell
Q7230A, request MIDCO Blue Print 7503-07 which details revised terminal call outs.
8. Honeywell R4795 discontinued (Nov. 93) construction features Honeywell RM7895 Flame Safeguards (Nov. 93)
9. Dual Main Valves as standard construction April 1, 1994 (UL 795 requirement)
Midco® International Inc. - 4140 West Victoria Street - Chicago, Illinois 60646 - toll free: 866 705 0514
6
tel: 773.604.8700 - fax: 773.604.4070 - web: www.midcointernational.com - e-mail: sales@midcointernational.com
713
8472 00
Printed in USA
Loading...