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i've been looking for a diagram for motor control using arduino and relays, and i only found tutorials using DC motors. i know you can use a contractor but for my project i want to be able to use Bluetooth and buttons as well as an LCD display, anyway i've already got everything setup and working, i only got a few questions.

1.) Would it kill a relay if i use a 1HP 220v 8a single phase motor to drive a bridge forward,(it's about 1200 lbs not that sure yet though hehe)

2.) is there a diagram for forward reverse using a 2 channel relay?

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    \$\begingroup\$ Something tells me that you should better not touch 220VAC just yet. \$\endgroup\$
    – user76844
    Mar 3, 2018 at 14:26
  • \$\begingroup\$ Single Phase motors are reversible. For some. woodgears.ca/motors/reversing.html \$\endgroup\$ Mar 3, 2018 at 14:46
  • \$\begingroup\$ Consider a 40A relay \$\endgroup\$ Mar 3, 2018 at 17:26
  • \$\begingroup\$ @GregoryKornblum, you guys said i shouldn't touch 220VAC just yet well yes it's true my experience with Electrical stuff isn't that much, and my course is totally not related to Electrical or Electronics but how would you learn if you wouldn't try right? i mean i always wonder why electricians don't get zapped when they hold two wires directly from the main breaker until i tried it myself and realized that if you hold only one line you're safe as long as you don't hold / touch any form of ground, that's also why i'm asking for the expert's opinion about the matter. to learn more \$\endgroup\$ Mar 4, 2018 at 1:16
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    \$\begingroup\$ You can experiment, indeed. But some results may be lethal. So it's better to first leard the subject, it's a very well known stuff. \$\endgroup\$
    – user76844
    Mar 4, 2018 at 4:51

3 Answers 3

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1.) Would it kill a relay if i use a 1HP 220v 8a single phase motor to drive a bridge forward,(it's about 1200 lbs not that sure yet though hehe)

A relay used to energize any motor must be rated for motor duty. It must be capable of handling the motor inrush current. It must be capable of disconnecting an inductive load. It must be capable of opening in the event that the motor is stalled. Knowing the weight is not the only requirement for determining the motor power rating. The friction load must be determined. The friction load includes the friction in the entire drive train including gears etc. used to reduce the speed. Gear losses can be as much as half the load, sometimes more. Not being sure is not a joking matter.

2.) is there a diagram for forward reverse using a 2 channel relay?

The reversing connections for an AC motor depend on the motor design. Some are not reversible at all. The ones that are reversible require the reversing of the starting or auxiliary winding with respect to the main winding. Universal motors (commutator AC motors) require the reversing of the field with respect to the armature.

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  • \$\begingroup\$ i see i see so what about a solid state relay for arduino? is there such a thing? \$\endgroup\$ Mar 3, 2018 at 15:53
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    \$\begingroup\$ The specs look good for the Fotek SSR-40 DA. When you link a product, it is best to link the specs rather than a picture. fotek.com.tw/pdf/etc_34.pdf Note that the specs appear to require the pictured heatsink. Using SSRs for reversing duty is quite risky. \$\endgroup\$
    – user80875
    Mar 3, 2018 at 16:54
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    \$\begingroup\$ @LouieJayOrellanaJayme - I am not getting involved with your question, I just wanted to help you with some experience: Beware, there are many fake (i.e. counterfeit) SSRs, especially those which are falsely labelled with the Fotek brand, like in the photo you linked. Only buy from reputable, traceable sources (i.e. not Ebay and similar) if you want to be confident of getting a "real one". \$\endgroup\$
    – SamGibson
    Mar 3, 2018 at 17:04
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    \$\begingroup\$ Reversing with SSRs is risky because you are depending on the circuit controlling the SSRs to prevent two SSRs for opposite directions from being turned on at the same time creating a short circuit through the SSRs. An H bridge created with 4 SSRs will not necessarily have the required level of electronic short circuit protection. \$\endgroup\$
    – user80875
    Mar 3, 2018 at 18:16
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    \$\begingroup\$ @LouieJayOrellanaJayme - "any brand you can recommend?" The problem isn't with the brand; it's with the sale of counterfeit devices. From previous research, I saw that Fotek SSRs were often counterfeited in certain marketplaces, but other brands might be too (I don't buy SSRs often enough to know). That's why I recommended to always buy from traceable sources - same applies to any brand, since any brand might be counterfeited. \$\endgroup\$
    – SamGibson
    Mar 3, 2018 at 18:59
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2.) is there a diagram for forward reverse using a 2 channel relay?enter image description here

Alternating current motors are either induction start-induction run, capacitor start-induction run, or capacitor start-capacitor run motors. AC motors may be single voltage or dual voltage motors with one or two run windings respectively. The run windings on dual voltage motors, i.e., 110/220 volt motors, are connected in parallel or series depending on the system voltage. The direction of rotation of an AC motor depends on the magnetic polarity of the start winding. Reversing the polarity of the "Start" winding, in relationship to the "Run" winding, reverses the direction of rotation of all single-phase alternating current (AC) motors.

enter image description here

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  • \$\begingroup\$ The OP's motor is single-phase. Given the OP's lack of knowledge on this subject your answer isn't going to help much. You can edit to improve. Look at Charles Cowie's answer for reference. \$\endgroup\$
    – Transistor
    Mar 3, 2018 at 15:59
  • \$\begingroup\$ is the example a relay or are you referring to a Contactor? because if that's a Contactor then there's no way i could hook that up to my arduino and expect it to magnetize, or i could if i'd use a relay but that's just too much redundancy i think \$\endgroup\$ Mar 3, 2018 at 16:07
  • \$\begingroup\$ Amos - Welcome :-) Since you copied those diagrams from somewhere, you need to reference them correctly otherwise you could be accused of plagiarism. For a diagram, then adding a link to the source web page where you found it is sufficient; if you copied them from a book, then title, page, author & publisher are needed. To help you see an example, here is a random answer of mine and you can see the "Original source" link below the image which I copied from an application note. \$\endgroup\$
    – SamGibson
    Mar 3, 2018 at 16:56
  • \$\begingroup\$ Louie if you do not understand relay logic than I will stand with Gregory Kornblum comment "you should better not touch 220VAC just yet." \$\endgroup\$
    – user179917
    Mar 3, 2018 at 17:00
  • \$\begingroup\$ Sam thank you but have a look at the bottom of the diagram (Source: Delmar/Cengage Learning.) \$\endgroup\$
    – user179917
    Mar 3, 2018 at 17:06
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1.) Would it kill a relay if i use a 1HP 220v 8a single phase motor to drive a bridge forward,(it's about 1200 lbs not that sure yet though hehe)

Why reinvent the wheel.

i know you can use a contractor but for my project i want to be able to use Bluetooth and buttons as well as an LCD display

Use a smart relay from schneider, omron, allen bradley or any know reliable company with a IEC or NEMA rated motor starters / contactor.

enter image description here

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    \$\begingroup\$ Page 188 of the datasheet shows that the contact rating is severly derated for non-resistive loads: Fluorescent tubes with electr. control gear (25,000 switching cycles) 10 x 58 W (at 230/240 V AC)". That's only 580 W. Again, the OP doesn't appear to have enough knowledge to use the information you have provided. \$\endgroup\$
    – Transistor
    Mar 3, 2018 at 16:51
  • \$\begingroup\$ Look at my Answers again " Use a smart relay from schneider, omron, allen bradley or any know reliable company "WITH" a IEC or NEMA rated motor starters / contactor." WITH a IEC or NEMA rated motor starters / contactor Thank You. \$\endgroup\$
    – user179917
    Mar 3, 2018 at 17:13
  • \$\begingroup\$ The smart relay will control the motor starter. The smart relay has a LCD Display, push buttons and some have and can be Bluetooth control. Plus if he has little experience working with line voltage, this is a safer way for him. I am a retied UL approve control panel designer and manufacture. (UL 508A) Thank You. \$\endgroup\$
    – user179917
    Mar 3, 2018 at 17:29
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    \$\begingroup\$ I know how to wire them and I understood your answer. (I'm an industrial controls engineer.) My point is that the OP obviously doesn't. I'm encouraging you to improve the answer so it's useful to the OP. \$\endgroup\$
    – Transistor
    Mar 3, 2018 at 17:39
  • \$\begingroup\$ @Transistor if you know, why ask? " (I'm an industrial controls engineer.)" Good for you, I'm a retired industrial controls engineer, UL approve control panel design engineer, Field service engineer , Licensed Master Electrician, certified control panel manufacture, PO2nd Class Construction Electrician that is still learning something new every day. That is why I like our trade, you never stop learning, Right. :) \$\endgroup\$
    – user179917
    Mar 3, 2018 at 19:25

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