push button stop/start single phase motor

[smashweld]

planning to use 2 of these individual style switches (https://www.screwfix.com/p/schneider-electric-xb7na31-green-flush-push-button-spring-return-no/955hv) to control the start/stop on the motor (pic of the motor plate below) for a lathge



no experience with this but from initial research using a NO switch for the start and NC switch for the stop with a contactor, with the NO start switch and aux contacts of the contactor wired in parallel should work, then have live and neutral going through the main contacts to the motor, is that right?

I see those swicthes I've linked to on screwfix are rated 120v operational voltage so those wouldn't be suitable?

any other advice, cheers

 

[Brad93]

What contactor are you using? Schneider also?

 

[smashweld]

not bought anything yet...just trying to figure out what's best

 

[Dave-sparks]

You can simply buy a self contained DOL starter and appropriately sized overload relay.

 

[brightspark]

or just buy a dol starter and wire the stop and start buttons in to it if u want them elswhere to the contact starter box

 

[daleyd]

As above an all in one starter box would see you right, but the switches are ok at 230v if you read the actual manufacturer data sheet, I’m not sure where Screwfix get the 110v rating from…

 

[Brad93]

Unlike everyone else i'm going to suggest buying separately as it will save you money and you can buy the exact switches you want.

I like Telemecanique (Schneider) Harmony XB4 switches

 

[daleyd]

Unlike everyone else i'm going to suggest buying separately as it will save you money and you can buy the exact switches you want.

I like Telemecanique (Schneider) Harmony XB4 switches

They are much better & more robust than the xb7 ones linked to, and modular so you add extra contact blocks, change the head for illuminated ones etc if you ever need to. (Unlikely on a motor stop start box but you never know!)

If you already have the contactor then no reason you can’t use switches as said it’s probably a bit cheaper, dol box is just convenient plug and play, so take your pick really!

 

[Alan Reynolds]

Is it not safer to use an NVR switch? Or did I misinterpret things.

 

[daleyd]

Is it not safer to use an NVR switch? Or did I misinterpret things.

The switches and contactor effectively make it an nvr

 

[brightspark]

They are much better & more robust than the xb7 ones linked to, and modular so you add extra contact blocks, change the head for illuminated ones etc if you ever need to. (Unlikely on a motor stop start box but you never know!)

If you already have the contactor then no reason you can’t use switches as said it’s probably a bit cheaper, dol box is just convenient plug and play, so take your pick really!

depends if he wants to fit the overloads for it

 

[smashweld]

buying individual parts will help with understanding/not being so scared of 240!

overloads...tell me more

it came with a 3 pin plug wired straight to the motor so...

 

[pawsnizzy]

You might want a latching off switch just in case

 

[brightspark]

they fit on to the contactor and trip out if you overload the motor or stall it https://www.toolstation.com/axiom-t...&ranSiteID=nz_xpRlxjVA-K2YpU6bFAFaLRytZ0lMhmA

 

[smashweld]

this is the original (now redundant) contactor from when it had the original 3 phase motor...assuming it needs 3 phases to operate at all?

 

[daleyd]

Overloads are matched to the size of the motor and provide over current protection. They are usually built in to a starter box, but you need to get the correct size for your motor. They will have some range of adjustment on them, you set them to the motor rated current and of the current goes above then it’ll trip out.

You can add them to your contactor separately if you wanted, they are available separately. Seeing as you don’t have any fitted at the moment then it’s probably a worthwhile addition!

 

[Brad93]

this is the original (now redundant) contactor from when it had the original 3 phase motor...assuming it needs 3 phases to operate at all?
View attachment 389869View attachment 389870

View attachment 389868

No but the coil voltage is likely 400v

 

[500e]

Have 2 starters for sale will put them in the for sale setion

 

[Alan Reynolds]

The switches and contactor effectively make it an nvr

I just thought an all in one unit is quicker and easier.

 

[daleyd]

I just thought an all in one unit is quicker and easier.

It is, but I was assuming from the post that the op had either some arrangement that warranted separate switches (eg the contactor sites away from the switches) or some bits he could utilise - but looking at the picture of the contactor then probably be as well buying a ready made dol starter.