Help Wiring Motor - Reversing Starter

Hello Chaps

I have inherited a motor with no starter. I have therefore bought a new switch but i am struggling to connect up. I would be very grateful if any forum members could give me some advise should they be familiar with this setup? It is a single phase motor, and i am trying to add a DOL reversing starter.

I think I see how the reversing is done, but I only see two switched legs, and it seems like for safety there should be three, unless this is corner grounded delta. I may look at it again later as I have time.

Right off the hop it I agree with Stroskovy and yes, if I get some today I will look up the bit that is bothering me.

One thing I will say is NICE wiring job,99.9% of the time open a piece of gear their are nary a ferrule to be found & 1 or two wire ties. Just a mess of elec-chickens tape that will be a sticky black mess in 1-2 days; and those damn copper pubes sticking out of every connection!!

He is in UK, their 240v has a neutral.

It would be OK anyhow as long as there is a proper disconnect, such as a cord and plug.

JST said:

He is in UK, their 240v has a neutral.

It would be OK anyhow as long as there is a proper disconnect, such as a cord and plug.

Click to expand...

I'm jealous.

Actually there are 3 switched legs. The 2 contact blocks are auxiliary contact blocks that piggyback onto the main 3 pole relay. The auxiliary contacts are wired so that it is impossible to energize both coils at the same time.

I would suggest first that you test the motor to check if it's operable before you try the starter.



The reversing starter appears to be a 3Φ unit. With that being said, your standard 3Φ voltage is 400V.
The operation coil voltage on the contactors is likely rated for 400V, not something that will work at 230V

Check the coil voltage to be sure of what you have.
Second thing with a 3Φ starter is parts of it need to be rewired to be suitable for 1Φ use.

Here's an example of a non reversible unit wired for 1Φ, notice that two of the power poles are wired in series, in order that all three poles of the overload are sensing the same current level.


Then a single phase motor starter would need an additional power pole, because for 1Φ you have 2 windings, a run winding that gets connected the same way each time, and then the start winding that needs to be reversed for change of direction. That would take more than 3 poles with standard contactors.

Check your starter spec sheet and coil voltages to see what you have. A drum switch would be likely more suited for a 1Φ .75HP motor.

Newlec NLRVM45C | Newlec 4V Motor Reversing Starter 5.5kW Grey | Rexeluk

Direct-On-Line Reversing - Series 3 Standard Starters - Web Store

Manuals

SAF Ω