LMC

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Operation & Maintenance
Manualfor

LEM-130, LEM-170& LEM-200 Series Motors

www.lmcltd.net

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SafetySAFETY WARNING:
This motor contains powerful magnets generating very large forces which can cause serious
injury. Before carrying out any servicing or repair please ensure you have read the service
manual and have the correct tools and safety wear available to you. Do not attempt to open
the motor casing if you are at all unsure about completing the service / repair.
We recommend approved service agents to assist you.
LMC ltd accepts no liability for any injury caused.

Warranty
All motors produced by LMC have a 12 month warranty against defects in materials or manufacture.
In the event of a warranty claim the motor needs to be returned to LMC for inspection andverification.
Your LMC warranty is subject to the conditions set out below:
The warranty is invalid if:
(a)
(b)
(c)
(d)

If the motor is damaged by running above its rated current or RPM, or with the brushholder in the wrong position.*If the motor is opened or serviced by anyone other than an approved service agent
except for replacement of the brushes or brush holder.
If the serial number label and other particulars are removed or altered.
If the motor is installed in an enclosed space without sufficient ventilation.

*This will particularly apply if the drive system used is designed with a very low reduction gear ratio sothat the motor runs at a very low speed and / or at high current e.g. used in hill climbing.

Maximum Current
The motor has a low resistance and is capable of drawing very high currents. It should therefore either
be operated through a controller set at, or below, the motor’s continuous current limit or be attached,through suitable gearing if necessary, to a system incapable of taking more than the current limit at fullvoltage. E.g. in a scooter or a boat. The controller also provides overload protection.
If peak current is to be drawn above the continuous rating, the the controller should limit this to 5
seconds before reverting back to the continuous rating. All applications need a soft start if the motor is
to be connected direct on line without a controller.
Vehicles should be designed to cope with the steepest gradient or the greatest acceleration they willencounter. Vehicles over 250Kg will almost certainly need a gearbox or other change of ratio, unlesstheir top speed is low.
For continuous running in boats we find the true continuous rating of most proprietary controllers isabout 25% of peak.

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Operating Speed
The continuous rating is based on the assumption that the motor is running at or near full speed – i.e. atfull voltage. If the motor is to run for more than a few seconds at reduced speed and voltage, or above
300 metres (1000ft) altitude, then the continuous current should be down-rated.

Use of Gearbox
It should be noted that if excessive current is drawn, the current is not reduced by dropping the voltage
and thus the speed of the motor, eg on a steep hill.
The solution is to design the drive with a mechanical ratio such that the motor is rotating at full speed
when maximum torque is required. To meet this requirement it is likely that a change of ratio will beneeded, a vehicle above 250kg will require a gearbox or other variable speed drive unless it has a very
low top speed, eg as a golf buggy (less than 15mph)
Do not lower the speed to resolve this issue. Reducing the speed (and thus the voltage) by means of anelectronic controller because this will not necessarily reduce the current, instead it will usually make theproblem worse by reducing the motors cooling through less ventilation due to lower speed of rotation.
Lower speed means less cooling; unlike a petrol engine, an electric motor should be run at full speed
most of the time; even at low load it will not over-speed.

Cleaning
The outside of the motor can be cleaned using a damp cloth or stiff brush. You can also use an aerosol
cleaning products to clean the outside of the motor, however only apply the cleaning solution to acloth/rage do not apply directly to the motor. Do not clean with water.

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Installation Drawings: LEM-130

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Installation Drawings: LEM-170

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Installation Drawings: LEM-200

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Installation Drawings: LEM-2X27

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Routine Maintenance
Depending on the frequency of use the routine maintenance will vary. High usage applications or where
air conditions are dusty, the motor may need checking after use e.g. racing.
If the motor is used at low current in an application involving little or no dust or other contamination themotor may only need servicing every thousand hours. Some displays provided with controllers can be
programmed to give a maintenance reminder.
External checks – When you turn the motor very slowly there should be a faint, smooth hissing soundfrom the brushes. Any unusual noises like rasping or clicking could indicate a problem. Also shake themotor shaft to see if there is any significant movement in the shaft or if there are any unusual noises
when the motor is running. To repair these faults please see the section on “Dismantling and reassemblyof the motor”.
Take off the terminal cap and check that the flexible leads to the brush holder are slack and are beingpulled tight between the terminals and where they pass in between the individual brush channels. You
should pull each lead to see the brushes are free to move in there channels. If you feel the motor has
accumulated very many hours of running remove the brush holder and blow dust out of the armatureusing compressed air. Complete this in a well ventilated area and ensure you are wearing a suitable maskso that you do not breathe in the dust.
Further information about removing can be found below in the section “removing the terminals from thebrush holder”.

Maintenance of main Parts
Belts or Chains – These must not be over tightened as this will cause rapid wear on the motor bearings
and will greatly reduce their life. When replacing follow belt and chain manufacturers instructions fortightness required and do not exceed this.
Remember that if regenerative braking is used the large vehicle pulley is driving the small motor pulley.
In this case the belt will need to wrap further round the small pulley to engage a sufficient number ofteeth to avoid the belt jumping over the teeth. This should be avoided as it will rapidly destroy the belt.
Enclosure – The motor relies on an unrestricted supply of ambient air for cooling; air temperature not toexceed 40 degrees C. If the motor is installed in an enclosure, then this should be provided with anample supply of ambient air, by means of suitable ventilation or a fan if necessary. Installation of themotor in a closed space without ventilation will invalidate the warranty. To ensure the motor does notoverheat please check the enclosure area of debris and check movement of ventilation fans regularly.
Replacement Bearings – If replacing bearings, use only high quality branded product such as RHP etc;
cheap alternatives could have only a third the life of original manufacturer’s product. Please note, we
make this suggestion as a result of more than 20 years practical experience; we have no commercial
relationship with any bearing manufacturer.
Brushes – Brushes should be checked once a year and after periods when not in use, it is possible undersome circumstances for carbon brushes to absorb moisture – e.g. if the motor is left in the cold, damp
environment such as garage or boat house over winter. When restarting a motor that has been left
standing for some time, it should be run for a minimum of 15 minutes at low current e.g.30 -40amps, todry the brushes. The current should be gradually increased over the next hour of running. If you areleaving for long periods then its possible to remove the brush holder assembly and store separately.
Under these circumstances or once a year, it would be advisable to check the brushes to make sure they
have not expanded and that they are completely free in the brush tubes. If there is any sign of sticking,

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the rubbing parts of the brush should be filed so that a 0.25mm feeler gauge can be inserted on one sideof the brush guide-ways in the retaining tubes.

LMC130 and 2X2 Models
It is recommended that the above versions are returned to the factory if the motors are required to be
stripped down due to special tooling needed however if the customer wishes to dismantle these forwhatever reason then please email engineering@lmcltd.net for specific details relating to make andmodel.

Replacing Brush holders
To replace a brush holder in your motor you need to fit the new holder with the 4 M4 cap screws but do
not lock down leave then slack so that the holder can be rotated within its slot by hand.
Connect a power source 12v or similar to the motor terminals ensuring that the motor is fixed down
switch the power supply on and by means of a volt meter measure the volts that is being feed to themotor, you need to find the highest voltage reading to locate the neutral position once found lock thebrush holder by means of the 4 cap screws and mark.

Dismantling and Reassembly
LMC170 and 200 frame models
Tools Required A bench vice with soft jaws (to prevent damage to the motor shaft) LMC assembly jig
 3mm Allen key
 6mm Allen key
 Internal circlip Pliers Small hammer Short M8x1,25 screw Bearing fit Loctite

Picture of the motor mounted in a bench viceand basic tools required to strip down

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LMC assembly tool, 3mm Allen key and 6mm Allen key10

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1
Secure the motor by the shaft in thesoft jaws of the bench vice.
Using the 3mm Allen key undo the 3of Cap screws that hold the brushholder cover in place.
Store in a safe place whilst
dismantling the motor.

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Once the cap is removed thisgives access to the brush holder,this again is secured to the motorby 4 of Cap screws, using thesame 3mm Allen key undo andremove from the motor.
Mark the holder to the casting sothat you put it back in the sameposition.
Again store in a safe place untilreassembly.

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3
Using the LMC assembly tool fix
to the commutator casting via 2of M4x25 cap screws (1 at eachend of the bar) and secure withthe 3mm Allen key.

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4Once the LMC tool is fixed inposition then turn the bar
clockwise which will lower thethreaded bar until it reaches thetop of the armature.

5Continue to turn the bar until you
create a gap of approx 20 to 25mm
between the casting and the bandcover.
Taking note of the indentation in theband cover, which there are 3 thesemust go back in the same position or
you will destroy the motor.
Lift of the top half and store in a safe
place free from metallic objects.

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6
Using the 6mm Allen key, unscrew
the centre cap screw as shown.
DO NOT UNDO THE 6 5MM CAPSCREWS.
Once completely undone thearmature will tilt to one side allowing
you to lift off, you will feel the forceof the magnet strength which willease as the armature comes awayfrom the drive casting.

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Once the armature is stored thisthen gives access to the drive
casting as shown take a note to see
if there are any shims fitted
between the armature and shaft.
If so lift of and store with thearmature, these are required tocentralise the armature within themotor case.

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Using the circlip pliers remove the top
circlip, then remove the casting from thebench vice turn over this then allows forthe shaft and bearing to be pushed out bymeans of the small M8 bolt fitted in theend of the shaft and hammer to knockout.
DO NOT HIT SHAFT DIRECTLY.

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