Magnetic Starter help for 5hp single phase.

[Patrick Irish]

I’m swapping a 5hp single phase baldor 1409t onto my powermatic planer. The vfd blew and a reputable one is the same price as a the motor.

I’m confused with proper magnetic starter and on/off switches.

The original starter is under the motor and then feeds to a push button on/off. I don’t think I can change the internals of the original starter. It says 18 amps and the new 5hp 1ph is rated at 23 amps.

I definitely think I need a new mag starter. BUT can I use the existing on/off switch? It’s a furnas 50cad3e. I can’t find amp ratings on it.

Pic of starter and switch attached.

[Patrick Irish]

I was thinking about this mag starter if I can use my existing switch.

https://www.amazon.com/dp/B01MRICCSY/ref=cm_sw_r_cp_awdb_t1_sb4FBb5WFG18P

This one is intriguing but the on/off seems suspect.

https://www.amazon.com/dp/B00ATCCYXK/ref=cm_sw_r_cp_awdb_t1_qf4FBbQ7H4FCB

[Mike Delyster]

Your Start/stop station will work fine with a 5hp single phase motor. The control circuits operating the coil don’t usually see more than a couple of amps.

[Bill Dufour]

Just make sure that switch can handle the control voltage of the new starter. If it is low voltage control no problems, if it is 440 or more their may be a problem unles s that switch is designed for it.
I believe 120 volts and below is considered low votage.
If it were me I would use a lighted off switch in a new enclosure. Consider adding another stop switch or two on the back side of the machine.
Bill D.

PS; I think you are little confused about how that switch works. it is low amps, just enough to pull in a coil that pulls in the big switch located in another bigger box that has high voltage in and high voltage out to the motor. It is kind of like a thermostat for a heater/ac unit in your house.

[George Makra]

Here is my thoughts and I have wired a lot of motors.
The 23 AMPS you see is by FLA which means FULL LOAD AMPS and very rarely do you see a motor run at 100%FLA.
Also contactor and starters are rated by size392137
So my suggestion is to just wire in the motor and see what it does.
If you don't have an amp meter run it for a few minutes unplug the planer and feel the contactor and see if its warm or hot.

BTW the difference between a starter and a contactor is a starter has overloads.
Which is nice but not necessary since the machine will never be run unattended so if there is a problem you just shut it down.

[George Makra]

One last thing is your switch is line voltage and should be ok.

[Patrick Irish]

Pic of current original 3 phase starter. Max 18amps and says 5hp at 460v. My new 5hp 1ph is actually 21.5 full load amps after reading nameplate. I don't think this starter will work.

https://preview.ibb.co/cR2cBo/5_BA86_A0_E_9033_4056_8_C05_082_FF933_F129.jpg




Pic of switch. How will I know if this switch doesn't work? Will the motor not turn off?

https://preview.ibb.co/cOwR48/595_C0114_97_B1_4_F99_9276_1047021_DB7_C2.jpg

[Matt Mattingley]

If you’re using the Nema charts, be careful. They are specifically designed for three phase. At 230 V three-phase it is very easy to look up the horsepower rating. If you’re using the same starter you divide the horsepower rating by half for single phase. So if you’re using a five horse power Single phase motor you need a number 2 starter.
https://www.engineeringtoolbox.com/nema-starters-d_918.html

[David Kumm]

If staying with a mag starter you need at least a size 1 with overloads adjustable or rated for 21 amps. The momentary start stop switches are usually rated up to 600v so they are seldom an issue but check that. The coil in the starter will need to be either 120v or 240v. For 120 you need a neutral or a transformer. You can adapt a three phase starter and just use two legs but make sure the coil is wired to the proper legs and not the unused one. Dave

[Peter Christensen]

I think it is better to get a magnetic switch made for single phase. All you need to do is mount it and connect the wires.
http://www.grizzly.com/products/5-HP-Magnetic-Switch-Single-Phase/T20551

[Patrick Irish]

I think it is better to get a magnetic switch made for single phase. All you need to do is mount it and connect the wires.
http://www.grizzly.com/products/5-HP-Magnetic-Switch-Single-Phase/T20551

I think I'll probably just do that.

I'd like to have the on/off switch close to the original location. I thought about just replacing the internals with something like this below BUT they are old and for a few dollars more I can have a brand new setup.

https://i.ebayimg.com/images/g/QQgAAOSwdzVXn9BR/s-l1600.jpg

[John Lanciani]

I think it is better to get a magnetic switch made for single phase. All you need to do is mount it and connect the wires.
http://www.grizzly.com/products/5-HP-Magnetic-Switch-Single-Phase/T20551

Ironically that’s actually a three phase starter, here is the schematic; http://cdn0.grizzly.com/manuals/t20551_m.pdf

[David Kumm]

I think that technically a single phase 5 hp motor needs a size 1.5 starter which I rarely see. ( Correction to my previous post ). I usually buy NOS old AB or CH starters for my machines. I've had the small Chinese and even the Euro small block contactors like Moeller and replaced far more of them than the old NEMA large enclosure type. Dave

[George Makra]

Yes indeed it is a three phase starter.
You could change the coil and the overloads but that would cost more than one of these.
https://www.amazon.com/Holdwell-42BF35AG-Definite-Purpose-Contactor/dp/B01J4Z92J6/ref=sr_1_14?ie=UTF8&qid=1535136914&sr=8-14&keywords=definite+purpose+contactor+2+pole+30+amp

[Patrick Irish]

Yes indeed it is a three phase starter.
You could change the coil and the overloads but that would cost more than one of these.
https://www.amazon.com/Holdwell-42BF35AG-Definite-Purpose-Contactor/dp/B01J4Z92J6/ref=sr_1_14?ie=UTF8&qid=1535136914&sr=8-14&keywords=definite+purpose+contactor+2+pole+30+amp

Not being an expert in this, is that Holdwell piece missing the reset button? Just looked it up, it's missing overload relay. Can that be added?

For $75 I can use this and keep the orig on/off switch.

https://www.amazon.com/Single-Phase-Magnetic-Starter-Control/dp/B016X22A38

[Phillip Gregory]

Essentially all magnetic starters are 3 phase units. Even the Grizzly unit listed is actually a 3 phase starter. You just only connect two of the input (L) connections and two of the output (T) connections, exactly which ones will be explained in the schematic for the starter. You can use a three phase starter on single-phase since the magnetic coil that trips all three connections only draws current from two of the lines, and you have two lines with a single phase input. But that is also why you need to follow the schematic, otherwise you have one of the coil inputs being an unconnected input and it won't work.

The horsepower rating at the same voltage for single phase will be lower than that of a 3 phase starter. That is primarily important for NEMA starters are they are rated in HP. An IEC starter such as that Grizzly unit is rated in amps, and as long as your motor's FLA is within the adjustability of the overload control, that starter is the correct size for that motor. Note that a 3 phase motor and a single phase motor will have significantly different HP at the same rated FLA.

Your 3 wire pushbutton control will be fine with any magnetic starter that can take a 3 wire remote pushbutton station.