Ramp up down switch single phase motor

[bigspark17]

Weired one. Looking for info or past experiences. Called to a garage very old ramp 40+ yrs old not working. Very old switcc looks like its burnt out, so before i take on finding a replacement i wanted to make sure motor ok. So bypassed up down switch and turned on isolator. (Single phase motor) and the ramp started mooving up, great i thought, so then reversed the polarity hoping the ramp would then go down, but to my dismay the ramp went up again.!
How can i get the motor to reverse?

 

[James]

Thanks @Lucien Nunes
i could see a contact was missing and as said I post number 8 it looks like a direct on line motor starter and overload unit.
I was wondering if it might be a hydraulic unit and if so, the motor only runs to lift, it will descend by gravity when valve is open.

 

[bigspark17]

Is this a hydraulic ramp e.g. an old Bradbury? If so the motor does not reverse, the ramp lowers by gravity when a valve is opened. This unit is just a single-direction starter. There is a mechanical interlock between the hydraulic valve and the starter.

A forward / reverse starter for a split-phase, capacitor-start or cap-start/cap-run motor has separate contacts for the start and run winding in each direction. They are cross connected so that both contactors energise one winding with the same polarity in both directions, but the other winding with opposite polarity for one direction. It doesn't actually matter which of the start and run windings is reversed, the key is that one is reversed relative to the other. This means that a reversible single-phase motor* must have four live cores in the cable to the starter as the start and run windings are connected separately. A single-direction motor has the two windings connected together internally and therefore only needs two live cores.

*Excluding small permanent split capacitor motors that have a common terminal in the winding, hence only three outgoing connections.

What makes you think the starter is burnt out?

Thanks lucien nice to hear a full and informative reply. The mechanics said there was smoke coming from the switch and the little transformer looks worse for wear, what would this transformer do?
Yes its a very old hydrolic ramp with no safety locks its really old,
Btw no valve to drop down

 

[mainline]

Thanks lucien nice to hear a full and informative reply. The mechanics said there was smoke coming from the switch and the little transformer looks worse for wear, what would this transformer do?
Yes its a very old hydrolic ramp with no safety locks its really old,
Btw no valve to drop down

I have never seen and can't think of a reason for a hydraulic ramp to need a motor that reverses.

Is this a 4 poster ramp ?

How is the ramp driven, is the ram pushing cables ?

 

[SparkySy]

I have seen a very old 4 post in the past that had a motor set up like yours with the motor only running in one direction. There was a lever on the hydraulics connected to a valve that changed the flow direction. It was lethal as there were no interlocks on it either so in the event of hydraulic failure if you were under it you would have been a red pancake!
I politely declined to look at it as I didn't fancy that on my conscience.
Sy

 

[James]

Thanks lucien nice to hear a full and informative reply. The mechanics said there was smoke coming from the switch and the little transformer looks worse for wear, what would this transformer do?
Yes its a very old hydrolic ramp with no safety locks its really old,
Btw no valve to drop down

The “transformer” is a solenoid that pulls the motor contacts closed.
if it is overheating, it is either faulty or the mechanical parts are not moving correctly.