Car ramp 3~ to single conversion

[Danhar]

Hi,
i am new to the forum and wondered if i could get some advice.
i have purchased a bradbury 4 post 3 tonne car ramp which runs off a 3 phase (and neutral) 1.5kw motor.

my problem is i do not have access to a 3 phase supply. Initially i bought a phase converter only to then find out that the phase converter was a 4 pin (3 phase and earth).
I am not in a position to buy a 5 pin version as they are very expensive so i am thinking of going down the motor change route.
i cant find any information on the internet which i am confident with regarding this matter.
the ramp needs the neutral wire to run the start button in order to lift the ramp via a hydraulic pump and a ram. The ramp lowers mechanically via a lever in order for the fluid to run back into the reservoir.

i would like to know what kind of power of single phase motor i would need in order for it to match the performance of the 3 phase motor. Obviously the ramp needs to be safe in order to work under, and the motor needs to be able to cope with upto 3 tonne on it.

am i right in thinking that a single phase 1.5kw motor with the same shaft diameter and length will go straight on and do the job?
if so, i still have the problem of needing the neutral wire from the main power cable to feed to the start button to work the motor.
could i run a live and neutral straight from the motor connections to the start button?
im pretty sure that the start button works the motor to lift the ramp as its held in, once released the motor stops.

any help greatly appreciated

 

[Marvo]

Hi Danhar.

Your post is kinda worrying me to be honest, you're obviously planning to do a major retrofit on a car lifting ramp and it sounds like you're not familiar with the way the machine is configured and how the fail safes and safety devices are interlocked. I'd immediately caution that if you perform work on this type of machinery and someone gets subsequently injured or killed you will find yourself in court being prosecuted.

There's inherent differences between single and three phase motors and especially in a high-torque start scenario or where braking is required a single phase motor may not be suitable. Wiring the motor directly from the start button is just asking for trouble, I can guarantee this will not end well.

My best advice is if you're even remotely in doubt about what you're about to do then please walk away before someone gets hurt.

Without a spec sheet and circuit diagram for the original ramp I couldn't advise any further I'm afraid.

 

[Danhar]

Hi marvo and thankyou for the reply,

i realise that what i need to do is not simple and also that there are extreme precautions that go with it.
the thing is i have a problem. I have a ramp with no power.
i am not saying that this is the course of action i am willing to undertake i am simply trying to find a way around my problem.
there must be a way to make it work because i am stuck with this ramp now.

if you can advise the best course of action to take id appreciate it.
i have a qualified electrician at my disposal so i wouldnt be doing it myself, but its upto me to find the solution before he can do the work.

thanks again

 

[shanky887614]

Hi marvo and thankyou for the reply,

i realise that what i need to do is not simple and also that there are extreme precautions that go with it.
the thing is i have a problem. I have a ramp with no power.
i am not saying that this is the course of action i am willing to undertake i am simply trying to find a way around my problem.
there must be a way to make it work because i am stuck with this ramp now.

if you can advise the best course of action to take id appreciate it.
i have a qualified electrician at my disposal so i wouldnt be doing it myself, but its upto me to find the solution before he can do the work.

thanks again

Sorry but if he can not recommend the best course of action then you should have doubts on his ability to do it safely.

Surely your electrician should be advising you on what you need and not the other way round.

(Why not get a quote to have 3 phase installed while your at it)

 

[Danhar]

I assumed this was a forum where i could get some helpful advice.
It obviously isnt :/

 

[shanky887614]

I assumed this was a forum where i could get some helpful advice.
It obviously isnt :/

Ok here is the best advice any of us can give you.

Ask your electrician for advice

Or get a local electrician that can have a look at offer his advice


You need someone with knowledge of safety ciruicts as well

 

[Marvo]

I think you're going to find members are hesitant to suggest specific solutions because without more info as I suggested above it would be just speculation or guesswork and given the type of equipment there's no room for this. It may be possible to fit a single phase motor, it may be possible to install a 230v VFD with a 400v 3-phase output...who knows?

I'm also concerned about an experienced electrician that's leaving his customer to dictate an appropriate solution to this kind of problem on this kind of machine.

 

[Darkwood]

Full agreement with Marvo here... this requires a lot of up front info and usually isn't straight forward unless you do as I suggest ...look into fitting a delta/star transformer to provide a N or depending what the N is needed for a small 400v/230v isolating TX again this isn't simply as a buy and fit option you have to have indepth knowledge of machine control standards and theoretical/practical knowledge and experience in such areas.... this is the difference sometimes between life and death and as ramps have to conform to strict standards you can't just dive in with your screwdriver and bag of spare parts.

Its a real shame we get new members on here that want to delve into things way beyond their understanding and competence giving little information and expecting the answers to drop into their lap...instead they get told indirectly what they are looking to do requires more then a simple solution and may require a competent Ramp Engineer or Electrical Engineer to actual look into it due to the safety aspects involved and what do they do GET STROPPY for been given sound safe advice...

Check the post count and thanks received of the people advising you then judge who might be talking with experience and try check their profiles if you want to know their background before you retaliate.

 

[snowhead]

This subject has been talked to death on many forums.

If it was a simple and cheap job to convert a 3 phase ramp to single phase, there wouldn't be any 3 phase ramps for sale, they would get snapped up immediately.

Unless you got the ramp for free, you've already spent more than the cost of a budget single phase ramp.

Try here for motor advice;

MM Engineering Services | Your Enquiry, Our Priority

 

[Danhar]

Hahaha. Ok thanks mate.

we'll leave it there fellas..........

 

[Darkwood]

Danhar - reading your profile and posts I assume your trying to resolve the technical side then telling the Electrician what it needs.. i see your work in power engineering may give you a gift of solving Engineering issues on Wind Turbines ... Unfortunately the term Electrician is not a person who would be qualified to design, alter and sign off any alteration to your Ramp controls.. in fact Ill be very surprised if he can understand the control and safety aspects of changing them ..a good grasp of BS60204 is a starting point which Electricians as a rule don't usually know even exists.

 

[Marvo]

I'm not in the UK butas far as I know this equipment would fall under EWAR and maybe other regs as well .

 

[Danhar]

Duely noted darkwood, i am truely out of my depth and i know this now.

it wasnt my intention to get 'stroppy' so appologies on my behalf

obviously the safest thing to do is scrap it and buy a single phase ramp!

cheers for your help

 

[Darkwood]

Don't get us wrong it probably can be done and maybe not to expensive but really need onsite viewing as i said the N can be replaced by 230v output of a TX off 2 phases of the supply... but unless you can provide full diagrams of the control set-up we can't say yes its would work without compromising the safety.

 

[Danhar]

Yes i understand and i cant provide any diagrams for it. Ill just leave it there and find another solution i think.

thanks again

 

[Knobhead]

That’s a novel approach. To save your electrician having to think you ditch a machine that with a bit of knowledge and work can be perfectly serviceable and buy a new one.

Hypothetical Question and Answer
Do you have an electrician you can call upon?
No
Did you think you would get step by step instruction?
Yes
Would you be prepared to pay for the professional advice?
No
Why do you think people won’t help?
Eeerr ……………………

 

[calpol91]

I'm probably gonna get slated for saying this but I did this (converted a 3 phase to single phase car ramp) about 2 weeks ago and it was easy for a spark, although I wouldn't suggest just having a pop yourself.... :75:

 

[Darkwood]

I'm probably gonna get slated for saying this but I did this (converted a 3 phase to single phase car ramp) about 2 weeks ago and it was easy for a spark, although I wouldn't suggest just having a pop yourself.... :75:

Converting can be simple in some set-ups but making sure its fail safe and meets safety criteria specified for ramp gear is a whole different ball game... Ill be interested to see their defense in court if someone gets crushed because of an Electrical fault or failure... knowing the standards protects you not knowing is a game of risk although it may still seem to work fine.