1. Expertise

a) By a visual check, we detect the existing conditions of the motors and record the situaion.

b) We check the conditions of coupling and pulley on motor shaft with caliper and recorded.

 c) We get all informations from the customer about motor to have an initial opinnion of the existing problems. Then to decide to do the next steps with a detailed expertise.

d) After dismentaling of coupling/pulley, we measure the coupling place runout with a comparator and recorded.

2. Disassembly

a) We record the positions of the coves first then unplluged and dismental them and put on the universal pallet.

b) The bearings and lubrication flanges are removed with a puller.

c) The brush and brush holders will removed.

d) Using with a suitable metal pipe, the rotor shaft will remove from the stator with cranes

3.Final Expertise

a) The tolerance of the cover and bearings and the shaft and coupling/pulley and inner&outer diameters micrometers will measure and recerded at mechanical expertise report.

 b)  The windings’ isolations will checked with megger and record the electrical expertise report. If isolation level is low and exemine the reasons.

c) we use avometer to measure the strength of heaters.

d) We control the core if it is demaged, if possible we use heating test. 

4. ReWinding Preparation

a)  The existing coils will move by the help of pulling and burning without giving any demage of the core..

 b) Depends on the demages, or any unexpected heating at the core, we can make partial or total dismentaling for repairing and insulation.

c) All insulations materials will be cleaned from the core by burning and then inside the slots are sanding.

d) After mechanical cleaning of the core, we use presured air and solvent for a final cleaning. The core will be ready fort he windings after using primer paint.

5. Rewinding

a-The slots insulation must be done with minumum F level persband. Presband edges cutted 1cm outside the slots and layed in the slots where we use glass or silicone tubing as insulation to support the coils which helps to give strength against magnetic loads.

b-It is very important to choose the right wire fort he windings. We use such a wire which has the resistance to 210 °C and corrosions free "Theic Polyesterimide  and covered Polyamide-imide" enamel grade 2 level. The coil needs special order for purcaising and most of the time we deliver from abroad.

c- The tools for preparing coils must be suitable fort he requested products.

d- We use polyester guide while putting coils in the slots avoid demages on core.

e- we use nomex presband between two coils to give strengt for insulation of two coils which has different voltage level.

f- In case the motors are running via a frequency converter, the poles of coils head are isolated with nomex presband for insulation of the slot’s outputs.

g- We formed H or F class fiber plates at the slots to cover coils to avoid electromagnetic effects.

h- We use silk or glass band at coil top sor polyglass band for high torque machines.

i-Parellezing or serial laying coils, we clean enamels from the wires by special hand tools.

j- The connection of coils are made by silver welding using cupper ring.

k- The cables fort he poles output is prepared according to the power of motors supporting. with H Class silicone tubing

l- We install RTU heat sensors to the stator windings at all poles and cables are silicone tubed to the terminals.

m- If the motor is slip ringed, we additionaly use polyglass band for coils head to give extra strength against centrifugal force.

n- The windins gets dry at the oven for 15 hours at 130 °C degree.

o-After drying, while the windings are hot, we varnished them with maximum spread over them.

p-After varnishing, we dry the windings at the oven for 15 hours at 130 °C degree.

r-We clean up residues of windings

s- We install special dehumidifier heaters at the windings which is fixed with F class polyglass band.

6. Winding Tests

a-We test the insulation with megger

b-We measure DC resistance of windings at 15 amp maximum 1/10000 sensibility

c-We use Hi-Pot and Surge tests for the windings between chassis to check insulation and HV resistance.

d-We control the winding’s RTU and resistance of heaters.

7. Cleaning, Maintenance and Repair Operations for the Windings and Parts

a- We clean all parts which do not need to repair and dried and varnished.

b-If there is brush holdars and isolators, we clean them at our sanding machine.

c-The rings of the motors we use our lathe machine to arrange %2 ovality level and get smoothness value 1,25/1,75 micrometer level.

d- The weared and varnished bolts get cleaned.

e- The demaged bearing and flanges are get overhould and checked with micrometer their tolerances.

f- Rotor and all the other rotating pars are balanced according to ISO 1940-1 standarts.

8. Assemblage

a- Rotor shaft will install inside the stator with the help of cranes.

b- Inner oil caps installed to the shaft

c- the bearings heated up over 80°C than the ambient temperature with demanyetisationed bearing heating tool. And then the bearings will demanyetized and install its own bed.

d- The oil reservoir of bearings is filled accordingly with gress oil.

e- All caps will put back its own bolts with washer using torged tools.

f- The gap between Brush holders and rings adjusted 2-2,5mm and installed.

Coupling/pulley are heated and installed to the shaft.

9. Final Test

a) Isolation tests of the windings are performed using megger.

b) The DC resistance of the excitation winding is measured.

c) The pole and the connection correctness is measured by the ancillary pole device.

d) The adjustment of the coal housing to the neutral region is performed by the neutral adjustment device.

e) The current and voltages are recorded by rotating the engine in its nominal voltage. The collector surface is cleaned by the coal lapping grinding wheels.

f) The engine is, by making connection with the cardan shaft, loaded on the generator that creates anticathexis by the 4 region and 2 region driver system. Arcing that may occur in the engine during this case is checked.

g) Vibration analysis and balance check are performed and the bearing performances are measured by making a vibration measurement on the housings when the engine is in its nominal revolution.

h) The sounds of the bearing flap and the bearings are listened.

i) The housing temperatures are measured and checked after 30 minutes of operation.

10. Packaging