Siemens EF 79 Series Instruções de Operação descarregar pdf (Página 7)

103-4E Issue 2 Spare parts, installation and maintenance of ac electric induction motors

An overgreased bearing will cause over-

heating of the bearing with the possible

escape of the grease, loss of lubrication

qualities, leading to ultimate bearing failure.

Lubrication procedure

The following procedure should be adopted.

1wipe clean the grease gun fitting and the

regions around the motor grease fittings

2 remove the grease relief plug if fitted.

Some motors will have one way grease

valves which should be left in place

3 add a small quantity of grease,

approximately 4 to 10 shots depending on

frame size

4allow motor to run for about ten minutes

in order that excess grease may be

expelled before refitting the relief plug.

Bearings fitted with rotating grease relief

or through grease valves will relieve

automatically

5 on initial start up or after relubrication,

‘bearing noise’ may result from the new

grease moving around the bearing.

This noise is normal and will disappear

after a few hours of running

Bearing change

When fitting new bearings the parts should

be lightly lubricated with grease.

The bearing should be driven onto the shaft

by pressure on the inner race only using a

short length of tube placed over the motor

shaft.

On larger motors it is easier to raise the

temperature of the bearing using an oil bath,

oven, or induction heating. The temperature

must be controlled to 120°C maximum.

The bearing should then be quickly slipped

into place, ensuring that the bearing is in

contact with the shaft shoulder.

When cool, ensure that the bearing is clean

and charge the bearing with the

recommended quantity of grease.

Bearings and housings should be one third

full.

Fitting Flange Adaptor

1 if required, remove foot as detailed in

terminal box position change

2 if required, reposition terminal box and

lifting lugs

3clean paint off the drive end endshield

spigot and remove all the plastic bolt-hole

cover caps. Apply a film of Hylamar

jointing compound on bare machined

surfaces for sealing and corrosion

protection

4 fit flange ring onto spigot, positioning

fixing holes to provide either BS or DIN

flange hole positions

5 bolt ring into position, using the same

size socket head bolts as used on the feet.

These are supplied with the flange ring kit

6 tighten the bolts to torque as given on

page 17, ensuring a progressive

tightening sequence

Change from ball/ball to roller/ball

construction (refer to Brook Crompton

for W-EF)

1isolate motor before commencing work

2remove fan cover and fan

3remove bearing cap screws

4remove endshield at both ends

5remove bearing circlips at both ends

6remove preload washer at non-drive-end

7replace drive-end ball bearing with new

roller bearing and refit circlip

8remove non-drive-end ball bearing and

inner bearing cap

9 fit new non-drive-end inner bearing cap

with shallow recess (identical to existing

drive-end inner bearing cap)

10 examine existing non-drive-end ball

bearing and either refit or replace

11 refit non-drive-end bearing circlip

12 repack bearings with new grease in

accordance with recommendations

13 ensure the lip, on both oilseals, is greased

14 refit both endshields and check that:-

a spacer O/D is the same as the bearing

O/D

b bearing spacer supplied is fitted into

the non-drive-end endshield bearing

recess

cslots in inner bearing caps are aligned

with endshield grease chutes

d correct location for bearing cap by

the use of a stud

e bolts are torqued up to

recommended figures

15 refit bearing cap screws, ensuring correct

torque to recommended figures

16 refit fan and fan cover

17 Turn shaft by hand to ensure free rotation

Maintenance

On-going maintenance

Induction motors by their very nature require

very little maintenance. However a regular

regime of inspection is recommended to

ensure minor problems do not escalate to

breakdowns. Typical intervals would be 2000

hours of operation or 3 months, whichever is

the sooner.

Checklist

• no visible damage ie fans cracked, fan

cowls bent, foot cracked etc

• no accumulation of dust or fibres on the

frame or around the fan inlet

• no significant corrosion of the lifting lugs/

eyebolts

• no excessive vibration

• no loose fasteners

• cables and earths are sound

• sealing of the motor and gland plate in

good condition

•insulation resistance adequate, imperative

this is checked after a prolonged shut-

down

• Note - Fumex smoke extraction motors

should be rewound after 5 years of

operation. See specification sheet 2215E

• regrease required, particularly large output

2 pole motors

• bearing condition

Periodic maintenance

Remove the cover and the fan which is

keyed, clamped, pinned or knurl located to

the shaft extension. Loosen and remove

bearing cover screws and endshield

bolts/studs. The endshields should then be

eased off their spigots.

The rotor can now be carefully withdrawn

from the stator, taking care not to damage

the stator bore and both stator and rotor

windings.

Having dismantled the motor, maintenance

can be carried out to remove all dirt. For this

purpose, the use of an air line supplying dry

compressed air under comparatively low

pressure is best, as a high velocity air-stream

can force dirt into the spaces between the

windings and insulation, etc. Grease-

removing solvents should only be used very

sparingly to avoid damage to impregnating

varnish or insulation.

Motors should be re-assembled in the

reverse order from dismantling,

remembering to ease endshields onto

bearings and spigots. Do not use force.

Before starting, check that the rotor revolves

freely. Ensure that the electrical connections

are correct and terminal nuts tight (see sec-

tion – Electrical Connection).

Installation and maintenance of

ac electric induction motors

1 2 3 4 5 6 7 8 9 10 11 12

Comentários a estes Manuais

Sem comentários

Siemens EF 79 Series Instruções de Operação Página 7

Comentários a estes Manuais

Manuais e produtos relacionados com Fogões Siemens EF 79 Series