/diy/ - Do It Yourself

>>1740372
>DOL motor starters

What are you attempting to do, are you going to need to start the motor under heavy load?

British imbecile

>>1740389
no, it's for a small lathe. starting it will be unloaded, the only load on it will be the friction of the gears and shafts of the lathe itself.

>>1740416
Sure anon, just install a triple breaker in direct line with the motor; why bother with a starter at all?

Starters give you pushbutton start and stop plus a means to ultimately shut power off and lock it out. 40 bucks is a bargain for all of that functionality honestly, a triple breaker or a shutoff will probably run you nearly the same.

>>1740419
right, because that's exactly what I was thinking, it's just a switch, maybe a tripple switch, but still just a switch. I have fuck tons of them salvaged from shit, I could even build a dedicated knife switch.
so, I'm not mistaken am i? a direct on line /DOL starter is nothing more than just a fancy switch?

>>1740424
It's not just a switch. It's two switches, a contactor and some overloads (see attached generic starter schematic). The idea is that all of the major current making and breaking is handled by a contactor, a device designed to prevent arcs from getting out of control if say a running motor is suddenly opened up and the field collapses and arcs across the feeders and causes an arc flash that blows up in your face giving you third degree burns and blinding you

>>1740472
>a contactor, a device designed to prevent arcs from getting out of control if say a running motor is suddenly opened up and the field collapses and arcs across the feeders and causes an arc flash that blows up in your face giving you third degree burns and blinding you
why the shit was NONE of this in any of the descriptions i read?
thankyou. seriously, this is critical info and it was missing from every fucking place I saw one of these for sale and every website talking about them.
i was wondering about the voltage spike in the back of my mind.
everyone >>1740372
get in here >>1740472

>>1740500
>why the shit was NONE of this in any of the descriptions i read?
Why do you think it's called a starter? And why would you believe it's just a switch? If only there was a source of information available out there to explain such things... Mmmmm. Oh right OP is the perpetual fag who can't google.
https://www.springercontrols.com/news/magnetic-motor-starters-basics/

>>1740566
i did google it
i found about 3 or 4 websites which all said variations on the same thing;
it's a breaker with a relay on the end.
i already have a circuit breaker in my fucking house, and a relay is just a switch.
that answer your questions?
and holy shit wouldn't you know it, the website you linked says exactly the same thing as all the others.
nothing about protecting against back emf.

>>1740577
You are literally retarded and should not be attempting to install high voltage electrical equipment. You’re going to get yourself killed or burn your house down.

>>1740582
>You are literally retarded
guess again nigger, i'm autistic.
so i didn't fully understand part of what they were saying. I'm good with electronics just not understanding things, no one is when people don't fully explain themselves.
e.g. from your link;
>A magnetic motor starter is an electromagnetically operated device that starts and stops a connected motor load.
relay aka a switch
>Magnetic starters consist of an electrical contactor and an overload which provides protection in case of a sudden loss of power.
understood as: breaker. I was only partly wrong.
They don't mention what the sudden loss of power they are talking about is, what part of the circuit in question is going open and that it would cause a massive back emf due to the collapsing field. now kindly fuck off out of my thread.

>>1740577
A contactor is to a relay as a transport is to a 1/2 truck.
Back emf don't mean shit and noone cares about it because you use a relay/contactor that's rated for the fucking load. Your autism is no excuse for trying to sub parts you don't understand. What you should be caring about is if your starter is meant to control a motor for your specific application.

If you gave a fuck about the motor overloading then an overload is appropriate.
If you care about multiple starts and thermal overload then other components a can be applied to spare the motor from melting.
If you care about lockouts, undervoltage, flying starts etc, there's ways to compensate for that too in a starter. How about an interlock like a footswitch or a limit switch? All possible with a starter in a compartment. It's only a matter of adding what you want.

That 40 britcucks starter is a steal for what you want to do, if it's rated and looks like the pic in your OP. Given its a standard, simple circuit it can be modified to do what you want for your application and it won't look like shit.
Or you can just get a 1/3 hp relay and a small pilot to latch it, but your protection will be based on overcurrent not overload, and you'll have no buttons, enclosure run lights etc.
Breakers are not starters. Fools use breakers to start motors. Same goes with switches. Can you use them? Yes, but you'd have to oversize the fuck out of them and expect them to cause many other issues that are beyond you at the moment.

BTW asshole I'm not >>1740582. But you are retarded because motor control concepts are everywhere online if you could only read or watch a fucking YouTube video.

Now kindly go educate your sorry ass and come back to post intelligent questions, not autistic screeching.

>>1740500
Hey OP, I hope this project works out for you. I'm happy that I could educate you and hope you follow through with this purchase (it'll be the correct choice). Remember to kill the upstream power if you're hard wiring your lathe or ensure its unplugged before you do this. Merry Christmas

>>1740617
Addendum: if your lathe runs backwards all you have to do is switch two of the phases, Godspeed anon and be safe. If you're worried you aren't doing it right, a commercial electrician will usually check your work at a MUCH cheaper rate than having to do everything themselves. Worth it if you're not confident in your own work.

>>1740424

As it's mono-phase motor you are after, probably with starting condenser, simple switch is more than enough.

However, congrats on trolling all those Holier-than-thou morons.

>>1740621
>switch 2 of the phases
>single phase motor
I see great minds like OP think alike, and lesser one seldom differ.

>>1740623
Because all equipment you buy now comes with a light switch right? Shit I guess I can rip out all those starters on my shit.

>>1740623
>>1740625
>>1740627
OP never specified if it was single or triple phase

>>1740633
Just can't read the OP can you, you dumb fuck. Please, keep posting.

>>1740500
>NONE of this in any of the descriptions i read?

>>1740633

>also the motor I'm looking to use it with is;
>https://www.machinemart.co.uk/p/13in-single-phase-4-pole-motor/

Oh shit oh shit oh shit shit shit...

>>1740500
>why the shit was NONE of this in any of the descriptions

Because this is electrical stuff, and it's basically magic to most of them. Also, they use terms to try and make things unintelligible to people outside the electrician club like "contactor" which is typically just a relay of some sort.

My favourite thing is stupid inspectors that don't realize the electrical code is the minimum, and they fault your stuff for being "not to code" because it was actually too safe! They just know how to follow the code, and don't understand the principles behind anything.

>>1740639
again, missing the point about how the contactor protects from back emf.

real diy anon(s) ;
>>1740617
>>1740621
thanks for the help bro, i knew to make sure the upstream power is off.

>>1740610
>1/3 hp relay
>implying relays are measured in horse power

>>1740788
Its reality.

>>1740688
lma try switching a big motor with a relay
it wont last long

a contractor is a relay with spark extinguish chambers the electromagnetism draws the spark between a stack of sheet metal.

>>1740877

It's still a relay though, contactor is the vulgar term used in the electrical field. No need to make up distinguishing features.

40 britshit bucks isn't bad for that.
I doubt its necessary for most equipment outside of industrial, high amp shit. The kind of stuff not used on a DIY forum or home shop.
You might just be poor...or cheap....actually you might just be a jew.

>>1741272
In my north American wood working garage I have a table saw, planer belt sander, dust collector, all 240v, all come with a starter like that from factory, albeit smaller. It's not about high amps it's about protecting the motor if something fails.

Its like noone in this thread owns decent tools outside of Fischer Price.

>>1740610
>If you gave a fuck about the motor overloading then an overload is appropriate.
>If you care about multiple starts and thermal overload then other components a can be applied to spare the motor from melting.
>If you care about lockouts, undervoltage, flying starts etc, there's ways to compensate for that too in a starter. How about an interlock like a footswitch or a limit switch? All possible with a starter in a compartment. It's only a matter of adding what you want.

Retard here checking in, dumb question but shouldn't you make sure your motor and it's branch circuit is 'sized' correctly first before discussing starters don't you have to 'size' the wire, breaker, motor first before calculating the proper rated starter and contactor you'll need from the NEC code book? (If you're in the US of course) It's been awhile since I've had to open up those table charts and use those formulas, but then again I'm a retard.

>>1741640
Upstream breaker/fuses protect the feeder. This handles feeder OC and instantaneous.

The contactor protects the rest of the branch. Overload is less amps than overcurrent. The relay controlling the contactor can be attached to the motor monitoring heat, motion, etc to determine if the motor can be energized or if it needs to be denergized. Sometimes a complex start, or a reversing start is required. This is where it would happen.
I like putting undervoltage, phase loss as well as interlock and plc control here. The combination of the contactor, control circuit, relays, etc is the starter.

So no you're not wrong. Nec and csa have tables for all of this. OP don't need any of it. He can wire for single phase, to his starter based on that motor load. The starter just gives him nice controls with potentially more features in the future. Also, overload protection.

>>1741653
>Upstream breaker/fuses protect the feeder. This handles feeder OC and instantaneous.

Yes

>>1741653
>Overload is less amps than overcurrent

But it's main job is for OL protection to burn itself out before the motor has a chance to ie those small tabs inside the OL part of the contactor (They're made of lead, no?) if memory serves correct.

>The relay controlling the contactor can be attached to the motor monitoring heat, motion, etc to determine if the motor can be energized or if it needs to be denergized.

The relay of the low voltage part of the circuit or anything at or under 120v?

>to his starter based on that motor load.

So it's based on the actual motor load and not based on inrush current? I've noticed other electricians tend to forget about sizing a motor's circuit based on the inrush current (been on a few jobs and seen that first hand) and wasn't sure if a starter in some cases had to be based off of that as well.

>>1741694
>But it's main job is for OL protection to burn itself out before the motor has a chance to ie those small tabs inside the OL part of the contactor (They're made of lead, no?) if memory serves correct.

Typically an overload device provides a contact in series with the main contactor coil when the time & current has reached the settings, be it through heat (replaceable bimetallic strips) or measured values. It's not one time use only usually. See pic in >>1740472.

>The relay of the low voltage part of the circuit or anything at or under 120v?

Yes. Whatever controls the M coil.

>So it's based on the actual motor load and not based on inrush current? I've noticed other electricians tend to forget about sizing a motor's circuit based on the inrush current (been on a few jobs and seen that first hand) and wasn't sure if a starter in some cases had to be based off of that as well.

If the motor runs you can let the contactor cut the circuit at levels lower than the upstream breaker, and at different curves. As for inrush, im not sure why you'd care about it so much. Cables are sized over nameplate FLA (as per code) so when you compare the damage line to the inrush from the motor it's usually far away on the curve and the breaker/fuses cuts it off before it gets there anyways.

Overloading means pushing a motor beyond its service factor over time. If one wishes to prevent burnout of the motor, the overload limits this, but it is not the end all be all for motor control. In any case, it only matters when the current is over the nameplate of the motor anyways, which is well below inrush or cable limits. But some motors are protected with rtds, acellerometers, ground faults, you name it.

Overload would be good in ops case unless he doesn't care about ever hitting that little motor's limits. It's likely way smaller than the smallest breaker in his home.

>>1741731
thanks anon, it's starting to come back to me now heh

>>1740666
>1/3hp
why is he even worried
a fucking light switch could do that
>>1741694
motor protection is set to what the motor lists on his data plate