Stepless Starter

[Spearmint]

We've been installing some new lighting and CCTV and a site and they've asked us if we can get this running. The control panel operates a few conveyors and shaker beds but the one that won't work is the crusher. They have a control box with all the switches etc mounted on and apparently this motor runs either forwards or reverse depending on the toggle switch position. Looks like a star delta starter setup but has this stepless rotor starter (soft starting?) wired to the other side of the same motor. All the control wiring is 24V driving 230V coils.

Anyone seen these before?

 

[Darkwood]

From a guy who does this for a living, my advice is keep well away -Getting involved with this could dig you a big hole and then have you shoulder all the responsibility of any future accidents, injury's or worse that comes about from its lack of compliance and poor maintenance.

PS - your motor as you rightly suggest has a stepless starting system and the motor will be a slip-ring so your comment of it looking like a star-delta starter is incorrect, its DOL with the Vapour Electrode stepless starter doing the what would normally be timed fixed resistive step system until full speed is attained.

 

[Lucien Nunes]

The Vapormatic is basically a 3-phase witches' cauldron connected to the brushes. High rotor current at switch-on covers the electrodes in gas bubbles, dramatically increasing the resistance. As the motor runs up and the rotor current drops, the bubbles disperse and more of the electrodes becomes exposed, decreasing the resistance. It is supposed to track the current so that the torque remains fairly constant through the start, then after a certain time it is bypassed by a contactor.

As Darkwood says the panel is a liability that you might be well advised to run away from. It has been fiddled with rather too much for my liking and might be an accident waiting to happen, until it is properly sorted out. I especially like the bare-ended blue wire dangling from the SP MCB.

 

[davesparks]

I think the smartest move will be to stick to installing the new lighting and cctv that you are there for and let them a specialist to deal with the machine.
As far as 'can you just have a look while you are here' jobs go then that one goes well beyond taking the wee wee