Cooling Blower Motor

Prévia do material em texto

GE Transportation
5GDY126A Centrifugal Blower 
Maintenance
Document No. GEK-91913, Rev. -
GEK-91913
5GDY126A Centrifugal Blower Maintenance
ii GE Proprietary and Confidential Information
© 2018 General Electric Company. All rights reserved. The information contained in this publication is the property
of General Electric Company and is disclosed in confidence. This publication is intended for use by GE customers
solely for purposes of operating and performing routine maintenance of purchased or licensed GE products, and it
shall not be reproduced, redistributed, retransmitted, translated, abridged, adapted, condensed, revised or other-
wise modified, in any form, in whole or in part, or used for any other purpose, or disclosed to third parties, without
the express written consent of GE. 
GE and Customer agree that the information contained herein does not purport to cover all details or variations in
GE products or to provide for every possible contingency with installation, operation or maintenance. Should further
information be desired or should particular problems arise that are not covered sufficiently for the user’s purposes,
the matter should be referred to General Electric Company. Any applicable Federal, State or local regulations or
company safety or operating rules must take precedence over any information or instructions given in the Technical
Documentation. GE has no obligation to keep the material up to date after the original publication. 
GENERAL ELECTRIC COMPANY EXPLICITLY DISCLAIMS ALL WARRANTIES OF ACCURACY, MERCHANTABILITY OR FIT-
NESS FOR ANY PURPOSE IN CONNECTION WITH THIS PUBLICATION AND USE THEREOF. 
If you are not an authorized recipient of this publication, you are hereby notified that any perusal, use, distribution,
copying or disclosure is strictly prohibited. If you have received this publication in error, please immediately return to
GE at the following address: GE Transportation, Technical Publications Department, Building 14, 2901 East Lake Rd.,
Erie, PA 16531. 
Revision History
Rev Date By Description
NEW Mar-2018 SKY Initial release of publication.
GEK-91913
5GDY126A Centrifugal Blower Maintenance
TABLE OF CONTENTS
Section Page
1. GENERAL INFORMATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1.1. INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1.2. SAFETY INFORMATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1.3. MODEL DIFFERENCES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
1.4. MAJOR EQUIPMENT-PART NUMBERS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.5. MARKING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.6. RELIABILITY / WARRANTY / LICENSING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
2. CONTROLS AND INDICATORS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
3. FUNCTIONAL DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
4. SCHEDULED MAINTENANCE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
5. REMOVAL AND RE-QUALIFICATION PROCEDURES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
5.1. BLOWER WITHOUT DISASSEMBLY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
5.2. BLOWER - DISASSEMBLY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
5.3. BLOWER COMPONENTS CLEANING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
5.4. BLOWER COMPONENTS INSPECTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
5.5. MOTOR TEST (BEFORE ASSEMBLY) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
5.6. MOTOR LUBRICATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
5.7. CENTRIFUGAL BLOWER - ASSEMBLY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
5.8. FINAL TEST . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
6. SUMMARY DATA. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
6.1. WEIGHT SUMMARY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
6.2. TORQUE VALUES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
GE Proprietary and Confidential Information iii
GEK-91913
5GDY126A Centrifugal Blower Maintenance
 This page is intentionally left blank.
iv GE Proprietary and Confidential Information
GEK-91913
5GDY126A Centrifugal Blower Maintenance
1. GENERAL INFORMATION
This publication covers the information about maintenance of the 5GDY126A centrifugal blower. 
1.1. INTRODUCTION
This maintenance includes maintenance of the blower without disassembly and with disassembly. And also, it cov-
ers pre-check, cleaning, post-check, testing, assembly, etc.
1.2. SAFETY INFORMATION
All applicable local regulations including any OEM test facility, Mine, Government, and Industry rules for working with
high voltage must be followed.
Wear appropriate and required Personal Protective Equipment (PPE). Consult with appropriate trained personnel to
ensure proper PPE is used in the specific work area.
Safety shoes and eye protection are mandatory always. Special protection must be worn, especially for hands, arms,
face and legs when handling parts in and around, e.g. Acid baths, Liquid Nitrogen vessels, welding stations and other
potentially hazardous areas.
Always use correctly rated lifting devices. Never put any part of your body, or stand under a suspended load.
Follow all applicable safety regulations as defined by your business.
Only use tools for their intended purpose.
Safety Warnings and Cautions appear throughout this publication.
Indicates a potential hazardous situation which, if not avoided, may result in minor or
moderate for injury.
Indicates a potential hazardous situation which, if not avoided, may result in equip-
ment damage.
The following is a summary of the WARNINGS and CAUTIONS that are found in this publication. Observe this safety
information carefully to avoid personal injury or equipment damage.
NOTE: Read these Warnings and Cautions before working on this drive system and proceeding to other sections
of this publication.
The centrifugal blower weighs approximately 685 lbs. (311 kg). Use appropriate lifting
devices for this weight. Failure to do so may result in injury or death.
The motor weighs approximately 270 lbs. (122 kg). Use appropriate lifting devices for
this weight. Failure to do so may result in injury or death.
Personnel performing cleaning procedures must wear suitable clothing, gloves, and
eye protection to avoid injury.
WARNING
CAUTION
WARNING
WARNING
WARNING
GE Proprietary and Confidential Information 1
GEK-91913
5GDY126A Centrifugal Blower Maintenance
When using compressed air, debris may present a hazard to personnel. Wear appro-
priate protective safety equipment and follow all railroad operating procedures. Fail-
ure to do so mayresult in injury.
The functional test requires a clean, secure / enclosed area to protect personnel and
equipment from debris and small objects that may become airborne during testing at
operational speeds.
Be careful while handling the impeller. It has sharp edges, Failure to obey this warning
may result in injury.
MEK (Methyl-Ethyl-Ketone) is a volatile, flammable solvent. The fumes should not be
inhaled. Use only in a well-ventilated area and take adequate precautions to protect
eyes, skin and hands.
The impeller wheel weighs approximately 42 lbs. (19 kg). Use appropriate lifting
devices for this weight. Failure to do so may result in injury or death.
For steam or water cleaning, do not use more than the limited pressure to clean motor
or assembly components. High-pressure fluids may damage components and may
result in premature assembly failure.
Be careful while removing the impeller. Do not cause damage to the impeller and its
housing.
Before checking the resistance (hi-pot test) of stator windings ensure that the motor is
clean and dry. Hi–pot voltage may permanently damage the motor windings if water
or debris is present.
Do not replace any damaged hardware (bolts, nuts, and washers) with standard hard-
ware. The 5GDY126A hardware is special purpose hardware. Order the replacement
parts referring to the related PARTS CATALOG, to ensure correct hardware. Failure to
do so may result in premature failure of the unit.
Failure to observe the relevant instructions for re-lubricating may, result in grease
leakage and/or bearing damage. Keep the equipment, bearings and grease free from
dirt to avoid damage.
WARNING
WARNING
WARNING
WARNING
WARNING
CAUTION
CAUTION
CAUTION
CAUTION
CAUTION
2 GE Proprietary and Confidential Information
GEK-91913
5GDY126A Centrifugal Blower Maintenance
1.3. MAJOR EQUIPMENT-PART NUMBERS
Table 1 describes the part numbers and the description of the 5GDY126A centrifugal blower.
1.4. MARKING 
All markings on the blower are made in such way that they are visible to maintenance and operating personnel
when the product is installed. Any markings added to the blower should be made in the same manner. 
1.4.1. Nameplate
Nameplates are to be securely fastened in the original location intended by GET. The following information are to be
appropriately stamped and clear:
• Model number
• Serial number (original)
• Completion date of service, year – month (example 03 – F)
• Re-Mfg. name or symbol
1.5. RELIABILITY / WARRANTY / LICENSING
The warranty is defined in the terms and conditions of the purchase contract and administered by GETS sourcing.
2. CONTROLS AND INDICATORS
Not applicable.
Table 1. Part Number and Item Description
Part Number Description Disposition
5GDY126A Blower Re-qualify
84A233342P2 35 HP Single Shaft Motor Re-qualify
84A233209P206 Impeller/ Wheel Assembly Re-qualify
84A233209P207 Housing Assembly Re-qualify
GE Proprietary and Confidential Information 3
GEK-91913
5GDY126A Centrifugal Blower Maintenance
This page is intentionally left blank.
4 GE Proprietary and Confidential Information
GEK-91913
5GDY126A Centrifugal Blower Maintenance
3. FUNCTIONAL DESCRIPTION
The 5GDY126A centrifugal blower (Figure 1) provides cool air to the alternator, control group electronic components
and the traction motors by drawing the outside air through the inlet of the blower end and expelling through the
bottom air outlet to the components. The 5GDY126A blower assembly is located under the rear of the control and
operator deck of the truck.
Figure 1. 5GDY126A Centrifugal Blower
The 35 HP blower AC motor (Figure 2) is a three–phase, AC induction motor, with a single-shaft extension mounted
horizontally to the impeller housing. The blower impeller is mounted directly to the motor shaft. The auxiliary inverter
in the OHV control group cabinet supplies power to the centrifugal blower's AC motor. The auxiliary inverter controls
the blower motor’s speed.
E-64145 
HOUSING IMPELLERMOTOR
SPEED SENSOR
COVER
GE Proprietary and Confidential Information 5
GEK-91913
5GDY126A Centrifugal Blower Maintenance
Figure 2. Typical 35-HP AC Motor
E-63378
MOTOR
SHAFT
SPEED SENSOR
ELECTRICAL CONNECTIONS
UNDER ACCESS COVER
LIFTING LUGS
MOUNTING SURFACE
6 GE Proprietary and Confidential Information
GEK-91913
5GDY126A Centrifugal Blower Maintenance
4. SCHEDULED MAINTENANCE
Table 1 provides the detail of the scheduled maintenance to be carried out on the 5GDY126A centrifugal blower.
NOTE: One year (truck-year) is equivalent to 6,500 hours of OHV operation. 
The 5GDY126A assembly requires an electric-drive motor-bearing lubrication at one-year interval between the gen-
eral overhaul time intervals. Add required quantity of D50E34 grease to each bearing through the grease fittings.
Refer to the appropriate scheduled maintenance publication for this OHV for recommended service and replace-
ment intervals.
Table 2. Scheduled Maintenance
Item Procedure Years
Motor Lubrication 1
Blower Assembly Maintenance 4
GE Proprietary and Confidential Information 7
GEK-91913
5GDY126A Centrifugal Blower Maintenance
 This page is intentionally left blank.
8 GE Proprietary and Confidential Information
GEK-91913
5GDY126A Centrifugal Blower Maintenance
5. REMOVAL AND RE-QUALIFICATION PROCEDURES
This section gives the instructions necessary to re-qualify, disassemble, clean, inspect, test and assemble the
5GDY126A centrifugal blower.
5.1. BLOWER WITHOUT DISASSEMBLY
This section covers the information about repairing the 5GDY126A blower without disassembling it.
5.1.1. Pre-Inspection and Data Collection
1. If the motor’s age is greater than 250 months, then scrap it and replace with a new motor.
2. Visually inspect the blower for obvious damage that needs repair. If the damage is heavy, then repair the blower,
refer to section 5.2., BLOWER - DISASSEMBLY thru section 5.8., FINAL TEST for re-qualification of the blower.
3. Rotate the impeller and make sure that it spins freely and does not make excessive noise. If not, then repair the
blower, refer to section 5.2., BLOWER - DISASSEMBLY thru 5.8., FINAL TEST for re-qualification of the blower.
4. Check the impeller for cracks and make sure that it is serviceable. If not, replace the impeller.
5.1.2. Blower Pre-Test
If all conditions described in section 5.1.1., PRE-INSPECTION AND DATA COLLECTION are met, then do the steps that
follow:
1. Perform megger test on the motor as per section 5.5.2., MEGOHMMETER MEASUREMENT (MEGGER). If the values
are not within the limits, then refer to section 5.2., BLOWER - DISASSEMBLY thru section 5.8., FINAL TEST.
2. Perform the bearing vibration test:
a. Connect the accelerometer to the blower, refer to Figure 3.
b. Run the blower at 220 VAC, 60 Hz and check for bearing vibration level for 1 minute.
c. If the vibration displacement is less than or equal to 0.0015 in. (0.0381 mm) continue to run the blower test,
else repair as per section 5.2., BLOWER - DISASSEMBLY thru section 5.8., FINAL TEST.
d. If the voltage, current, speed, and bearing vibration are within the limits, continue to run the blower test. If
they are not within the limits, then repair the blower, refer to section 5.2., BLOWER - DISASSEMBLY thru sec-
tion 5.8., FINAL TEST.
e. Check the bearing vibration again at the end of the testing. If the vibration is not as per specifications, then
repair the blower, refer to section 5.2., BLOWER - DISASSEMBLY thru section 5.8., FINAL TEST.
f. If the single-phase current is not within specifications, then repair the blower, refer to section 5.2., BLOWER -
DISASSEMBLY thru section 5.8., FINAL TEST.
GE Proprietary and Confidential Information 9
GEK-91913
5GDY126A Centrifugal Blower Maintenance
Figure 3. Vibration Measurement Location
5.1.3. Final Maintenance
If all the conditions described in section 5.1.1., PRE-INSPECTION AND DATA COLLECTION and 5.1.2., BLOWER PRE-TEST
are met,then do the steps that follow:
5.1.3.1. Blower Washing and Painting
1. Use the rope or a rubber material to wrap around the shaft to keep direct water spray from entering the bearing
through the gap between the shaft and end-cap.
2. Clean the complete blower assembly.
3. To drain the water out of the bottom of the scroll, tilt the blower up to one side.
4. Re-paint the blower as necessary.
5.1.3.2. Cables and Conduits Replacement
Check the cables and conduits for any damage. If necessary, replace with new.
5.1.3.3. Grease Line Installation (If needed)
If the motor does not have grease lines to allow greasing from both the sides of the motor, disassemble the motor as
per section 5.2., BLOWER - DISASSEMBLY and install the grease lines as per Figure 4. Then grease the motor as per
section 5.6., MOTOR LUBRICATION and assemble the motor as per section 5.7., CENTRIFUGAL BLOWER - ASSEMBLY.
E-63385
ACCELEROMETER 
CONNECTING
LOCATION
10 GE Proprietary and Confidential Information
GEK-91913
5GDY126A Centrifugal Blower Maintenance
Figure 4. Motor Grease Lines
E-64103
GREASE LINE
GREASE LINEGREASE FILLING PORT
GREASE RELIEF
FITTINGS BOTH
ENDS
GREASE FILLING PORT
GE Proprietary and Confidential Information 11
GEK-91913
5GDY126A Centrifugal Blower Maintenance
5.2. BLOWER - DISASSEMBLY
This section gives the information necessary to disassemble the blower.
NOTE: Numbers in parentheses ( ) refer to items or text found in Figure 5.
The centrifugal blower weighs approximately 685 lbs. (311 kg). Use appropriate lifting
devices for this weight. Failure to do so may result in injury or death.
5.2.1. Impeller Removal
The impeller wheel weighs approximately 42 lbs. (19 kg). Use appropriate lifting
devices for this weight. Failure to do so may result in injury or death.
1. Using standard wrench loosen and remove the hex nuts (2), the washers and the lock washers from the inlet
flange surface plate. Restore fasteners for re-use.
2. Remove the inlet flange surface plate.
3. Using standard wrench loosen and remove the capscrews (1), flat washers, lock washers and the nuts that
secure the blower inlet screen and inlet plate. Restore fasteners for re-use.
4. Remove the inlet screen and the inlet plate from the impeller housing inlet.
5. Remove the cotter pin, then castle nut with standard wrench, and the retaining plate which locks the impeller on
the shaft. Retain the fasteners for re-assembly. Refer to Figure 6.
Be careful while handling the impeller. It has sharp edges. Failure to obey this warning
may result in injury.
6. Use a standard puller tool and remove the blower impeller from the rotor shaft by pulling/sliding the impeller
wheel away from the rotor shaft. Refer to Figure 7.
7. Carefully remove the impeller from its housing.
Be careful while removing the impeller. Do not cause damage to the impeller and its
housing.
WARNING
WARNING
WARNING
CAUTION
12 GE Proprietary and Confidential Information
GEK-91913
5GDY126A Centrifugal Blower Maintenance
Figure 5. 5GDY126A Centrifugal Blower
E-63377
INLET SIDE
MOTOR SIDE
3
FRONT VIEW
AIR
INLET
AIR
OUTLET
SPEED SENSOR 
COVER
AC MOTOR
1
2
BLOWER 
HOUSING
INLET FLANGE
SURFACE
LIFTING 
HOLES
ROTATIONLBA
LBV
LBH
LBH
MH
MV
LBA
MV
MH
GE Proprietary and Confidential Information 13
GEK-91913
5GDY126A Centrifugal Blower Maintenance
Figure 6. Cross Section of Blower Inlet
E-64045
MOTOR
 IMPELLER
WHEEL ASSEMBLY
RETAINING
PLATE HEX CASTLE
NUT
COTTER PIN
INLET SCREEN
INLET PLATE
14 GE Proprietary and Confidential Information
GEK-91913
5GDY126A Centrifugal Blower Maintenance
Figure 7. Impeller Puller Tool (41C636629)
5.2.2. Electric Motor Removal
The electric motor can be removed from the impeller housing after the impeller is removed. Refer to Figure 8.
NOTE: If applicable, disconnect all the external electric cable connections.
1. Using standard wrench loosen and remove the four AC motor mounting capscrews (3), nuts, flat washers and
the lock washers that secure the motor mounting base on the impeller housing. Retain all the fasteners for re-
assembly.
The motor weighs approximately 270 lbs. (122 kg). Use appropriate lifting devices for
this weight. Failure to do so may result in injury or death.
2. Attach the appropriate lifting device to the lifting holes on the AC motor. Lift and remove the AC motor away
from impeller housing.
3. Place the motor on a flat surface with the shaft oriented horizontally. Retain the motor shims if any for re-
assembly and discard the gasket.
E-64474
REF. DESCRIPTION
3 HYDRAULIC CYLINDER
4 PRESSURE CAP
5 CYLINDER PLAT
6 STUD
7 PULLER PLATE
8 NUT
9 BOLT
11 RETAINING RING
7
0.562
11
488 5
6
3
9
ALL DIAMENSIONS
IN INCHES
5GDY126A2 IMPELLER PULLER PART 41C636629G4
WARNING
GE Proprietary and Confidential Information 15
GEK-91913
5GDY126A Centrifugal Blower Maintenance
Figure 8. Motor on the Housing
5.3. BLOWER COMPONENTS CLEANING
This section gives the information about cleaning of the blower assembly and its parts. 
Personnel performing cleaning procedures must wear suitable clothing, gloves, and
eye protection to avoid injury.
When using compressed air, debris may present a hazard to personnel. Wear appro-
priate protective safety equipment and follow all railroad operating procedures. Fail-
ure to do so may result in injury.
For steam or water cleaning, do not use more than the limited pressure to clean the
motor or assembly components. High-pressure fluids may damage components and
may result in premature assembly failure.
5.3.1. Motor
1. Arrange the motor assembly in a position accessible from all directions.
2. Steam clean the motor assembly. Make sure that the pressure value is not exceeding 30 psi (207 Kpa). 
3. Bake the motor for four hours in an oven not exceeding 248ºF (120ºC) to remove all moisture.
E-64102
BOLTS
MOTOR
IMPELLER HOUSING
WARNING
WARNING
CAUTION
16 GE Proprietary and Confidential Information
GEK-91913
5GDY126A Centrifugal Blower Maintenance
5.3.2. Impeller and Housing
1. Clean the impellers with a non-petroleum based non-corrosive cleaner and lint free cloth.
2. Clean the sheet metal impeller housings and the base:
a. Clean the housing and base with steam, make sure that pressure does not exceed 30 psi (207 Kpa).
b. Clean the housing and base with hot water spray, make sure that you maintain the water temperature does
not exceed 180ºF (82ºC). 
NOTE: Use any one of the above methods for cleaning.
5.4. BLOWER COMPONENTS INSPECTION 
This section gives the information about inspection of the blower assembly and its parts.
5.4.1. Motor 
Inspect the motor for any visual and observable damages (like bearing failures), overheating (Figure 9), etc. Discard
and install a new motor, if it is necessary.
Figure 9. Damage on Motor
E-64473
WINDING WITH
SHORTED COIL
WINDING GROUNDED
AT THE EDGE OF SLOT
WINDING DAMAGED
DUE TO OVERLOAD
WINDING DAMAGED
BY VOLTAGE SURGE
GE Proprietary and Confidential Information 17
GEK-91913
5GDY126A Centrifugal Blower Maintenance
5.4.2. Impeller 
1. Check for the cracks on the blades or hub. If severe cracks are found on the blades or hub, replace the impeller.
2. Check for the wear from airborne debris. If severe wear has occurred, replace the impeller.
3. Check for the impact damage. If it is found, replace the impeller.
5.4.3. Impeller Housing
1. Check for the impact housing damage. If holes or extended cracks are found, replace the impeller housing.
2. Check for the internal wear and any debris inside the impeller housing. If severe internal wear is found, replace
the impeller housing.
NOTE: If necessary, use mirror and a flashlight to inspect the inner side of the housing.
3. Check for the external wear. If severe external wear is found, replace the impeller housing.
4. Check for the cracks. If severe cracks are found, replace the impeller housing.
5.5. MOTOR TEST (BEFORE ASSEMBLY) 
There are various tests for the electric motor. The motor should be replaced withnew when the motor fails to meet
the minimum criteria for any test. The following sections detail the testing procedures.
5.5.1. Motor Shaft Runout
The motor shaft runout should be measured in a vertical plane as close as practicable to each end of the shaft. The
shaft runout should not exceed 0.001 in. (0.0254 mm) Total Indicated Runout (TIR). 
5.5.2. Megohmmeter Measurement (Megger)
1. Apply 500 VAC megohmmeter to all the motor leads (T1, T2, or T3) from the leads to a ground on the motor or
blower. 
2. Megger should be performed for 1 minute.
3. The minimum acceptable megohmmeter reading is 5 megaohms resistance at 113°F (45°C).
4. If less than 5 megaohms resistance is measured, clean as per section 5.3.1., MOTOR and do the test again.
5.5.3. Motor Stator Cold Resistance Check
Use a double-bridge ohmmeter and check resistance between all motor stator fields (T1 to T2, T2 to T3, and T3 to T1).
Acceptable resistance range is between 0.1630 ohms to 0.1730 ohms at 77°F (25°C).
18 GE Proprietary and Confidential Information
GEK-91913
5GDY126A Centrifugal Blower Maintenance
5.5.4. No Load Running Test
NOTE: The motor bearings require grease before operation. Add approximately 2 oz. (57 g) of D50E34 grease to
each bearing through the grease fittings.
1. Secure the motor on a rubber isolation pad.
2. Supply three phase 220 VAC line-to-line voltage at 60 Hz. 
3. Ensure that, the following parameters are in the given range:
• The acceptable speed of the motor is between 1782 rpm to 1818 rpm. 
• The acceptable current range in the phases (T1, T2, T3) is between 13 amps to 17 amps. 
• The acceptable vibration range measured at the bearing caps (both bearing caps) is equal to or less than
0.015 in. (0.0381 mm). Refer to Figure 3 for location of measuring the vibration with help of VB meter.
NOTE: If the vibration range is excessive, the motor must be replaced. After replacing the motor, test for vibra-
tion again.
5.5.5. Quarter Voltage Impedance Test
Apply single-phase 55 VAC at 60 Hz between the phases (T1–T2, T2–T3, and T3–T1) in turn, and record the amperes.
Current should be between 37 amps to 45 amps.
5.5.6. Rotor Reluctance Test
1. Apply single-phase 55 VAC at 60 Hz between T1-T2, T2-T3 and T3-T1.
2. Measure T1 amperes.
3. Rotate the rotor at approximately 5 rpm by hand.
4. Watch the ammeter for sharp current fluctuations, while feeling for rotating resistance at the same time.
NOTE: Fluctuation of 3% or more in current and simultaneous rotating resistance indicates that there is an open
conductor. Replace the motor.
5.5.7. High Potential (Hi-Pot)
Before checking the resistance (hi-pot test) of stator windings ensure that the motor is
clean and dry. Hi–pot voltage may permanently damage the motor windings if water
or debris is present.
Hi–pot the motor stator windings 3000 volts 60 Hz for one minute. Observe leakage current. If the leakage current is
excessive, the coil insulation has failed. Replace the motor if leakage current is high.
CAUTION
GE Proprietary and Confidential Information 19
GEK-91913
5GDY126A Centrifugal Blower Maintenance
5.6. MOTOR LUBRICATION
Failure to observe the instructions for re-lubricating may result in grease leakage and/
or bearing damage. Keep the equipment, bearings and grease free from dirt to avoid
damage. 
Once the motor passes all the inspection and test specified in section 5.4., BLOWER COMPONENTS INSPECTION and
5.5., MOTOR TEST (BEFORE ASSEMBLY), lubrication must be carried out on the motor.
1. Secure the motor on a rubber isolation pad and connect the motor to a 220V AC line to line voltage at 60Hz.
2. Run the motor until it gets warm, then stop the motor and remove the power.
3. Clean dirt and debris from around the grease relief plugs.
4. Remove the relief plugs from the grease fittings (Figure 10) and clear the opening and relieve the tube of hard-
ened grease. This may be accomplished with a twisted wire brush or sturdy pipe cleaner.
Figure 10. Motor Power Side without Speed Sensor Cover
5. While the motor is still warm, add grease with a hand operated grease-gun (Figure 11) until fresh grease
appears on the end of the relief holes (Figure 4). 
CAUTION
E-63386
SPEED SENSORELECTRICAL CONNECTIONS
UNDER ACCESS COVER
GREASE
 FITTINGS
20 GE Proprietary and Confidential Information
GEK-91913
5GDY126A Centrifugal Blower Maintenance
Figure 11. Lever Action Grease-Gun with Coupler
6. Leave the relief plug temporarily open. Start the motor and run for 10 to 20 minutes to expel any excess grease.
7. Stop the motor. Replace the relief plug.
5.7. CENTRIFUGAL BLOWER - ASSEMBLY
This section gives the instructions necessary to assemble the 5GDY126A after component tests and inspections.
NOTE: Numbers in parentheses ( ) refer to items or text found in Figure 5.
Do not replace any damaged hardware (bolts, nuts, and washers) with standard hard-
ware. The 5GDY126A hardware is special purpose hardware. Order the replacement
parts from the related PARTS CATALOG, to ensure correct hardware. Failure to do so
may result in premature failure of the unit.
5.7.1. Motor
The motor weighs approximately 270 lbs. (122 kg). Use appropriate lifting devices for
this weight. Failure to do so may result in injury or death.
1. Attach the appropriate lifting device to the lifting holes on the AC motor. Carefully lift and place the AC motor
onto the impeller housing.
2. If applicable, place the shims under the motor mounting feet.
3. While lowering the motor onto the base, make sure that the mounting holes are aligned between the motor and
base.
4. Install the lock washers, flat washers, nuts and the four mounting capscrews (3) through the motor and base
mounting holes.
5. Torque the capscrews (3) to 45 ft.-lbs. (61 Nm). Refer to section 6.2., TORQUE VALUES.
E-56902
CAUTION
WARNING
GE Proprietary and Confidential Information 21
GEK-91913
5GDY126A Centrifugal Blower Maintenance
5.7.2. Impeller
The impeller wheel weighs approximately 42 lbs. (19 kg). Use appropriate lifting
devices for this weight. Failure to do so may result in injury or death.
Be careful while handling the impeller. It has sharp edges. Failure to obey this warning
may result in injury.
1. Check the tapered fit of the armature shaft and the inside bore of the fan hub for any nicks or burrs and remove
them. Then clean these mating surfaces with a suitable non-oily cleaner.
2. Place the impeller hub/impeller assembly onto the taper of the armature shaft, then measure and record the
cold advance position. Mark the position on the armature shaft and impeller hub for heated assembly.
3. Check the impeller-to-shaft fit as follows:
a. Apply Prussian blue to the inside of the impeller bore.
b. Push the impeller onto the motor shaft firmly. Do not turn the impeller.
c. Remove the impeller from the motor shaft.
d. The motor shaft fit must show minimum 80% bluing.
MEK (Methyl-Ethyl-Ketone) is a volatile, flammable solvent. The fumes should not be
inhaled. Use only in a well-ventilated area and take adequate precautions to protect
eyes, skin and hands.
4. Clean the motor shaft with a cleaner such as MEK (or equivalent). Wipe the shaft dry with a clean Scott® No. 150
paper towel or equivalent.
5. Clean the impeller hub bore with a cleaner such as MEK (or equivalent). Wipe the impeller bore dry with a clean
Scott® No. 150 paper towel or equivalent.
6. Mount the impeller on the motor shaft. To obtain a zero-advance reading, snug the cap, to the shaft shoulder
hand tight, and torque the two machined bolts to 10 lb.-ft. (13.56 Nm) diametrically opposite the puller bolt
holes. Position the two feet of the indicator support, one on each of the bolts, and the dial indicator stem on the
cap. Set the dial indicator to read zero. Refer to Figure 12.
7. Carefully remove the indicator and impeller from the shaft.
Nalco RC® (Nalco Chemical Company) cleaner contains a small percentage of Alcohol,
resulting in a low flash point. To avoid serious personal injury, keep the NalcoRC® liq-
uid away from open flame.
8. Apply Nalco RC® cleaner with a Scott® No. 150 (Kimberly-Clark Corp.) paper towel to the motor shaft, avoiding
drips and runs under the shaft. Let the Nalco RC® cleaner dry, do not wipe it off. A very light, even haze should
be visible on the shaft.
NOTE: Nalco RC® cleaner on the motor shaft impedes sliding of the impeller, which tends to limit the advance.
Therefore, the impeller must be applied with a firm snap.
WARNING
WARNING
WARNING
WARNING
22 GE Proprietary and Confidential Information
GEK-91913
5GDY126A Centrifugal Blower Maintenance
9. Heat the impeller to a 149°F (65°C) rise above the motor shaft temperature, and apply the impeller onto the
shaft.
NOTE: Allow 30 minutes before next step.
10. Without disturbing the zero advance reading of the dial indicator (obtained in step 6) check the impeller
advance on the motor shaft as in step 6. Refer to Figure 12.
11. The change in the indicator reading is the impeller advance. This impeller advance must be within 0.011 to 0.016
in. (0.2794 to 0.4064 mm). If the proper advance is not achieved, remove the impeller and re-install.
12. Remove the indicator, support, cap, and the bolts.
13. Install the retaining plate and castle nut on the motor shaft and torque the nut to 100 ft.-lbs. (136 Nm). Refer to
section 6.2., TORQUE VALUES. 
14. Make sure that the cotter pin is serviceable. If not, install a new cotter pin on the end of the motor shaft. Refer to
Figure 6.
15. Mount the inlet plate and inlet screen on the impeller housing inlet using the nuts, lock washers, flat washers,
and the capscrews (1). 
16. Adjust the inlet plate and make sure that the impeller does not come in contact with the inlet plate.
17. Torque the capscrews (1) to 45 ft.-lbs. (61 Nm). Refer to section 6.2., TORQUE VALUES.
18. Mount the inlet flange surface plate using the hex nuts (2), the washers and the lock washers.
19. Torque the hex nuts (2) to 15 ft .-lbs. (20 Nm). Refer to section 6.2., TORQUE VALUES.
GE Proprietary and Confidential Information 23
GEK-91913
5GDY126A Centrifugal Blower Maintenance
Figure 12. Measuring Impeller Advance
E-34014B
0.50 DIAM
0.100
BOLT (41B537769P2)
1/2-13 X 3/4 LONG
0.270
BOLT 
(41B537769P2)
COLD 
HOT
ADVANCE
0.011 TO 0.016
MACHINE OFF
BOLT HEAD AS
SHOWN IN
PHANTOM
BOLT 
(41B537769P2)
CAP 
(41B537769P1)
IMPELLER
0
10
20
30
40
10
20
30
40
50
+-
0.25
1.00-12 TAP
0.62
CAP 
(41B537769P1)
1.050
DIAM
SECTION A-A
ALL DIAMETERS TO
BE CONCENTRIC
WITHIN 0.010 T.I.R.
0.020+-
0.020+-
2.00
1.62
0.50
32
0.20
KNURL
1.050
DIAM
0.50
DIAM
1.250 STK
DIAM
A A
ALL DIMENSIONS IN INCHES
24 GE Proprietary and Confidential Information
GEK-91913
5GDY126A Centrifugal Blower Maintenance
5.8. FINAL TEST
This section gives the instructions necessary to test the blower after completing its assembly process.
The functional test requires a clean, secure / enclosed area to protect personnel and
equipment from debris and small objects that may become airborne during testing at
operational speeds.
5.8.1. Vibration Displacement
1. Mount the blower assembly on a pedestal or frame. The bottom surface of the blower should be at least 6.0 in.
(152.4 mm) above the floor. The pedestal or frame should be firmly fixed to the floor plate. Bolt the blower to the
frame using all four mounting holes. The discharge openings should be clear for air flow.
2. Connect the blower assembly to a 3-phase, 220 VAC, 60 hz power supply. Connect T1 to Terminal A, T2 to Termi-
nal B, and T3 to Terminal C. Check the blower for counterclockwise rotation facing the inlet.
3. Measure the RPM of the blower assembly. Speed should be between 1782 rpm and 1818 rpm.
4. Measure the vibration displacement with a portable vibration analyzer (IRD vibration analyzer Model No. 306 or
equivalent) at five places, refer to Table 3.
Table 3. 5GDY126A Blower Vibration Displacement Limits
Model
Vibration Displacement
Measurement Points
Maximum (in.) Maximum (mm)
5GDY126A
Blower Axial (LBA)
0.0015 0.0381
Blower Horizontal (LBH)
Blower Vertical (LBV)
Motor Horizontal (MH)
Motor Vertical (MV)
WARNING
GE Proprietary and Confidential Information 25
GEK-91913
5GDY126A Centrifugal Blower Maintenance
 This page is intentionally left blank.
26 GE Proprietary and Confidential Information
GEK-91913
5GDY126A Centrifugal Blower Maintenance
6. SUMMARY DATA
This section gives the information about weights of the major equipment and necessary torque values required for
the hardware used in this procedure.
6.1. WEIGHT SUMMARY
6.2. TORQUE VALUES
NOTE: Use Table 5 for values as a guide to ensure satisfactory tightening of bolts and nuts.
Table 4. 5GDY126A Centrifugal Blower - Weight Summary
Description LBS KG
Motor 270 122
Blower (Impeller + Housing) 416 189
Total Weight 685 311
Impeller Wheel 42 19
Table 5. Torque Values
Items Part Number Description
Torque
 (ft.-lb.)
Torque 
(Nm)
Figure 5
1 N14P29024B13 Capscrew hex HD, 1/2-13UNC x 1-1/2 LG 45 61
2 N245BP25B Hex nut, 3/8-16 UNC 15 20
3 N14P29040B13 Capscrew hex HD, 1/2-13UNC X 2-1/2 LG 45 61
Figure 6 Castle Nut N215P82B Hex castle nut, 1 - 12 UNF 3A 100 136
GE Proprietary and Confidential Information 27
GEK-91913
5GDY126A Centrifugal Blower Maintenance
 This page is intentionally left blank.
28 GE Proprietary and Confidential Information
	1. GENERAL INFORMATION
	1.1. INTRODUCTION
	1.2. SAFETY INFORMATION
	1.3. MAJOR EQUIPMENT-PART NUMBERS
	1.4. MARKING
	1.4.1. Nameplate
	1.5. RELIABILITY / WARRANTY / LICENSING
	2. CONTROLS AND INDICATORS
	3. FUNCTIONAL DESCRIPTION
	4. SCHEDULED MAINTENANCE
	5. REMOVAL AND RE-QUALIFICATION PROCEDURES
	5.1. BLOWER WITHOUT DISASSEMBLY
	5.1.1. Pre-Inspection and Data Collection
	5.1.2. Blower Pre-Test
	5.1.3. Final Maintenance
	5.1.3.1. Blower Washing and Painting
	5.1.3.2. Cables and Conduits Replacement
	5.1.3.3. Grease Line Installation (If needed)
	5.2. BLOWER - DISASSEMBLY
	5.2.1. Impeller Removal
	5.2.2. Electric Motor Removal
	5.3. BLOWER COMPONENTS CLEANING
	5.3.1. Motor
	5.3.2. Impeller and Housing
	5.4. BLOWER COMPONENTS INSPECTION
	5.4.1. Motor
	5.4.2. Impeller
	5.4.3. Impeller Housing
	5.5. MOTOR TEST (BEFORE ASSEMBLY)
	5.5.1. Motor Shaft Runout
	5.5.2. Megohmmeter Measurement (Megger)
	5.5.3. Motor Stator Cold Resistance Check
	5.5.4. No Load Running Test
	5.5.5. Quarter Voltage Impedance Test
	5.5.6. Rotor Reluctance Test
	5.5.7. High Potential (Hi-Pot)
	5.6. MOTOR LUBRICATION
	5.7. CENTRIFUGAL BLOWER - ASSEMBLY
	5.7.1. Motor
	5.7.2. Impeller
	5.8. FINAL TEST
	5.8.1. Vibration Displacement
	6. SUMMARY DATA
	6.1. WEIGHT SUMMARY
	6.2. TORQUE VALUES