Hi everyone,I was gifted a 350-liter industrial air compressor (CompAir Marshall Branson 2000, UK). The previous owner had already started working on it, and I’m now trying to put everything back the way it was originally.

I’m not an industrial electrician, but I do have some basic electronics knowledge. I would really appreciate some guidance from someone who has experience with this kind of equipment.

From what I’ve been able to research so far, it looks like the system uses, a 3 way switch, a star–delta starter with an overload relay and three timers. I’m especially curious why three timers are used?
Which timer is the ROT?
Also after P/SW we see the line (5) is connecting to the D contactor K2, is this connecting to the add block (TA1 DN 11) NO rather than the actual contactor itself?

Before I start reconnecting the circuit, I’d love to better understand how the electrical system is meant to work. I’ve included a reference showing how the wiring was before it was dismantled.

Thanks so much for your time and any help you can offer!

 

I see you have already got a great deal of help on the Practical Machinist forum!

 

I see you have already got a great deal of help on the Practical Machinist forum!

Thats very true. I still need clarity. I had to post again here to give context to make everything make sense.

Which timer is the ROT?
Also after P/SW we see the line (5) is connecting to the D contactor K2, is this connecting to the add block (TA1 DN 11) NO rather than the actual contactor itself?

 

From what I see in the photos, the ROT timer is an Omron relay

 

Hello,

You also had some info on control.com:
https://control.com/forums/threads/industrial-compressor-circuit-diagram-help.55619/

Bertus

 

From what I see in the photos, the ROT timer is an Omron relay

Thank you for making that clear.