240v car ramp motor issue

john_rdy · Mar 3, 2011

hi everyone

First and foremost id like to apologise, I am not an electrician I just would like a bit of your knowledge if any of you can help id be iternally thankful.

I recently bought a 2 post car ramp that's single phase, not modifed to be but is actually made as a single phase ramp. Made in 1988 by and english firm and is screw post.

I'm struggling to find a motor for it. The motor that's on it is a 2hp 1.5kw. So I bought one from machine mart, same rating. Only to find that yes it can go forwards and reverse but you have to have it wired for one or the other. If I put a car on it and wire it to the up, it really struggles and the motor actually stops with the car a foot off the ground! I called out a ramp engineer and he told me clarke motors are chinese c@@p and not worth anything and I needed to buy off him a £400 motor

Is this the case? Do these motors have a special name where they can be switched between the two?

I have the old motor bit someone has cut the wires and capacitors and now I have no idea how to fit them back on or which order they go in

Thanks in advance

John

telectrix · Mar 3, 2011

he's right about the clarke motors, but £400 is steep. to get it reversing requires control gear. you would have an up button and a down button. really needs an electrician on the job. i have a contact for motors, sensible price at ruabon, welsh border. a 3hp is around £120.

john_rdy · Mar 3, 2011

telectrix said:
he's right about the clarke motors, but £400 is steep. to get it reversing requires control gear. you would have an up button and a down button. really needs an electrician on the job. i have a contact for motors, sensible price at ruabon, welsh border. a 3hp is around £120.

thanks for your reply, yeah it has all the control box but its not compatible with the clarke motor. so i got an electricain to wire the power straight to the motor just to see if the ramp itself was ok. which it seemed to be..... please dont think im doing this myself, but the guy ive got is a friend and is the first to put his hand up and say i know very liuttle about motors

the supplier your talking about..... please dont think im being rude but are they good motors? ive already bought a machine mart one for £120 and it seems rubbish. it has one capacitor, which is belived to be a start capacitor not a run capacitor which is possibly what i need?

im a little out of my depth so any help is warmly welcomed.

thanks thus far
john

bugsy · Mar 3, 2011

Contact Fyfe and Wilson in Bishops Stortford, they will be able to supply the correct motor, needs to be wired through change over contactors ( which it proberbly already has )

Of course if Id have read the post properly I would have realised its single phase!
I humbley receive doughnut of the month award!

Marvo · Mar 3, 2011

Is the new motor the same pole configuration as the old one (is it the same 'RPM' rating)?

Zimmer · Mar 4, 2011

Are you sure that there is anything wrong with the old motor apart from a missing capacitor.
Could you not get a connection diagram from the manufacturer, as you seem to have the control box already ?

john_rdy · Mar 5, 2011

Ahhh, so you can obtain wiring diagrams for motors? I can't recall the exact name but I'm sure it was leroy something..... and it was made in france.

The revolutions are 1500, which as I understand it make it a 4 pole motor, feel free to correct me. I was going to contact the guys suggested above on Monday. But I wanted to clarify a few thing first. Are there two types of forward and backwards motors? As a few suppliers I've spoke to have said you wire it one way to go forward, with brass plates crossing the two terminals. Then to go another you change these brass terminals to join two other terminals.. but I have a junction box for that on the ramp but it doesn't seem compatible from what my local sparky was saying..

Thanks for all your help so far.. I've also been told I need a cap start and a cap run to give the motor extra juice. Is this also correct?

Zimmer · Mar 5, 2011

Don't know anything about your particular motor, I would guess its a Leroy Somer from your description, maybe like this type.
http://www.leroy-somer.com/catalogue-industrie/fichiers/3-LS-mono-en.pdf

typical type diagram here

Changing direction is achieved by reversing the start winding.

Normally with a single phase motor you would need a capacitor to start, without a capacitor, it will just "hum" and burn out. The second capacitor is for power factor/radio interference purposes.

Yes the direction the motor travels is decided by the arrangement of the motor brass links, but in an arrangement like yours where the direction is changed many times per day, the motor cable is connected up permanently to both terminal arrangements and ran to a control panel which has a forward and a reverse contactor/relay.
The panel could have two momentary (only operates while your finger is on the button) switches labelled "up" and "down" .These switches will select which contactor operates and will also be interlocked to prevent both directions being selected at the same time.

john_rdy · Mar 6, 2011

Zimmer said:
Don't know anything about your particular motor, I would guess its a Leroy Somer from your description, maybe like this type.
http://www.leroy-somer.com/catalogue-industrie/fichiers/3-LS-mono-en.pdf

typical type diagram here

Changing direction is achieved by reversing the start winding.

Normally with a single phase motor you would need a capacitor to start, without a capacitor, it will just "hum" and burn out. The second capacitor is for power factor/radio interference purposes.

Yes the direction the motor travels is decided by the arrangement of the motor brass links, but in an arrangement like yours where the direction is changed many times per day, the motor cable is connected up permanently to both terminal arrangements and ran to a control panel which has a forward and a reverse contactor/relay.
The panel could have two momentary (only operates while your finger is on the button) switches labelled "up" and "down" .These switches will select which contactor operates and will also be interlocked to prevent both directions being selected at the same time.

yeah thats the sort of thing i was after. i have stripped the old motor down, more for curiosity purposes than anything else, and i can see that on the centrifugal switch it was really burnt out, so i have cleaned it up with emery cloth. but putting it back together and the motor goes very stiff on one 1/4 of the revolution. both bearings seem fine and free turning, and there seems to be no contact inside on the windings

in your opinion would it be best using a 3 hp motor? i have found a few second hand motors which i may have a punt at, not to save money but they seem to be older and therefore better built maybe?

it seems hard to figure out whats a good motor and whats a bad one as the plaques seem to all say the same

BROOKS 2HP SINGLE PHASE MOTOR & STARTER. on eBay (end time 06-Mar-11 20:07:47 GMT)

i saw this one

SIEMENS 3HP SINGLE PHASE MOTOR & STARTER. on eBay (end time 06-Mar-11 20:19:53 GMT)

and this one

all from the same guy, but am i right in thinking i need a cap run as well as a cap start as the motors going to be constantly under load?

again i am thankful of your time and replies on this

John

Marvo · Mar 7, 2011

john_rdy said:
in your opinion would it be best using a 3 hp motor? i have found a few second hand motors which i may have a punt at, not to save money but they seem to be older and therefore better built maybe?

it seems hard to figure out whats a good motor and whats a bad one as the plaques seem to all say the same

If you use a 3 hp motor then the frame size will be bigger so it might not physically fit. The shaft size will also be larger so your drive might not fit. Finally the run current will be higher so you might also need to replace the thermal overload protection accordingly as well. This probably wouldn't worry you too much but the efficiency would also be lower if you use a larger motor so it would use more electricity to do the same work. I would stick to the same specs replacement motor.

With regard to which make of motor I would just stick to any well recognised brand name. I personally use a lot of the blue WEG motors and Zest motors as well.

geofff · Mar 13, 2011

Might just be coincidence but a company called "somers" make vehicle lifts, perhaps its an old version of their machines? if "leroy-somers" was the motor manufacturer, might be worth giving them a call. web link here