Advice and help on Electrical motor safety , potential danger. Greatly appreciated

Thread Starter

Stefi

Joined Jul 27, 2022
13
Hello dear community

I am new to this forum and appreciate to be able to seek help from people I've read from for a while now on this forum.

I recently bought a cabbing grinder machine from India and now recognize that the motor(1/2hp 230v~ can add a link if necessary) doesn't have any safety label or certificate whatsoever.
I know close to nothing about motors or electricity and ask myself if it is safe to use the machine. To be honest I don't even dare to plug it in. Before I assumed that it would be safe like any other product one never worried about. I assume that the circuits and wirings must be isolated from the outer shell but what if it has leaks?
I ask myself if I am overcautious because it is not from the USA or Europe or if my concerns are legitimate.

And in general even if one has a motor from a reputable company, what happens when after many years the isolation fails? How does one recognize this failure before getting a shock. Does this always pose a hazard threat?

Thank you in advance for your help and effort.
Stefi
 

Ya’akov

Joined Jan 27, 2019
6,264
Wellcome to AAC.

Your caution is a good thing, While it may not have certifications, a lot of industrial equipment from India is actually reasonably good. A link to the item would be very helpful in evaluating the potential for trouble.

Even if it is lacking in best practice measures for safety, there is a good chance it can be modified to be much safer. External measures including GFCI/RCD or AFI could be a start. But it will help to see the link and photos, particularly of inside.
 

Thread Starter

Stefi

Joined Jul 27, 2022
13
Thank you very much Eric and Ya'akov. Eric I wanted to use the machine athome and I don't see any visible device. But in Switzerland an RCD(RCD) IΔn ≤ 30mA should be obligatory in every houshold. This specifications above don't tell anything to me, can you get something out of it?


Ya'akov , the seller did not give me any spec sheet. Here is the link to the machine https://www.jewelsntools.com/6-cabbing-machine.html

and I also will try to contact their motor supplier for additional information and post it here asap.

I hope I was able to provide some useful information for now. I am quite sad to be honest since I gave around 2000 $ of my students budget for this machine and don't even feel safe to use it. Let alone the no brand submergible water pump which is of less importance right now.
Thank you again for your help and time.
Stefi
 

Ya’akov

Joined Jan 27, 2019
6,264
The principle test is to measure the resistance between the ground/earth wire in line cord and the metallic housing of the motor. If this low, that’s good. Then, using a GCFI/RCD/AFCI on the circuit powering it will ensure that if something goes wrong the power will be cut.

It is probably OK because the grounding is probably correct but if you test you can be sure.
 

Ian0

Joined Aug 7, 2020
5,839
The most important thing as it is being used in a damp environment is that the case is connected to earth. If the cable is round in cross-section it probably is. You mentioned that you were a student. In that case there will be an electrician in your institution responsible for Portable Appliance Testing (Prüfung ortsveränderlicher Elektrischer Betriebsmittel in German), who will go around testing computers, kettles etc. every year and attaching a little sticker to them to say that they are safe. See if you can find him and ask if he will test your bench grinder. It will take less than five minutes, and I’m sure he’d be willing to do it unless he is a particularly miserable old sod. If you suggest that you just might be using it at the college he’d have to test it.
At a guess, motors from India are usually reasonably well made and safe. I’d be more worried about the grinding wheels, and I’d certainly be wearing my eye protection.
 

Thread Starter

Stefi

Joined Jul 27, 2022
13
Thank you all for your answers. I am so glad really.
"MaxHeadRoom" I will plug it in with a Swiss type J (type 12) plug which has 3 pins and the center pin should be for earthing, do you mean this or some additional measure I am not aware of? Forgive me please I am very far away from the engineering field and am pretty clueless. That's why I appreciate all of your patience and goodwill soo much.
I am sure that we have some power cutting measure standard here but I don't know if it is enough " responsive" to prevent harm.

Ian I will try to find a person like this thank you for the thorough advice and also for the reminder of wearing glasses.

No matter from which country and quality standard it is( I found out that it complies with the Indian standard of Is 996 https://law.resource.org/pub/in/bis/S05/is.996.2009.pdf)
I ask myself how one can recognize when the inner insulation gets damaged and some kind of leakage happens. Does one get an eletrical shock always? This would mean that one can use the machine until one day one gets a random eletrical shock. Again forgive me for my very unworthy questions. This is the thing which occupies my mind the most. How trustworthy are electrical motors of this kind in case of a fail.
I am a little overcautious right now since I just realized how careless we normal folks are with these type of things.
Thank you again for all of your time.
 

Ya’akov

Joined Jan 27, 2019
6,264
Thank you all for your answers. I am so glad really.
"MaxHeadRoom" I will plug it in with a Swiss type J (type 12) plug which has 3 pins and the center pin should be for earthing, do you mean this or some additional measure I am not aware of? Forgive me please I am very far away from the engineering field and am pretty clueless. That's why I appreciate all of your patience and goodwill soo much.
I am sure that we have some power cutting measure standard here but I don't know if it is enough " responsive" to prevent harm.

Ian I will try to find a person like this thank you for the thorough advice and also for the reminder of wearing glasses.

No matter from which country and quality standard it is( I found out that it complies with the Indian standard of Is 996 https://law.resource.org/pub/in/bis/S05/is.996.2009.pdf)
I ask myself how one can recognize when the inner insulation gets damaged and some kind of leakage happens. Does one get an eletrical shock always? This would mean that one can use the machine until one day one gets a random eletrical shock. Again forgive me for my very unworthy questions. This is the thing which occupies my mind the most. How trustworthy are electrical motors of this kind in case of a fail.
I am a little overcautious right now since I just realized how careless we normal folks are with these type of things.
Thank you again for all of your time.
If the motor housing is earthed, and you have an RCD which looks for current flowing where it shouldn't be and interrupts the circuit, it is electrically as safe as any electrical appliance you otherwise use.

Here is an example of a combined receptacle and RCD from a random website but it is supposed to be for Swiss use.
 

Thread Starter

Stefi

Joined Jul 27, 2022
13
Okay, I will try to inquire more about rcd, I read that it is obligatory for every household since 2009 but the only distinguishable system belonging to the electrical grit is this dusty box, does it look familiar to you?
And also in other german forum I read that the electric is being shutt off whe the current flows where it shouldn't but that in this fraction of a second you probably could die. That made me forget any feeling of security using electrical products.
 

MaxHeadRoom

Joined Jul 18, 2013
25,630
Many industrial style bench machines do not necessarily use a GFI/RCD.
As long as the machine frame is connected to an earth GND system it is often sufficient, this of course, also relies on the supply referenced to earth GND using a valid grounding method.
A local GFI outlet is often used where double insulated 2 wire equipment is used and/or for outside use equipment.
Bathrooms, exterior outlets etc.
A Main GFI/RCD is also used where a location cannot obtain a valid ground return resistance.
 

ericgibbs

Joined Jan 29, 2010
16,002
hi Max,
I would still use a pluggable RCD plug to connect to the 230V AC mains.
It maybe belt and braces, but for the minimal cost of an RCD, money well spent.

We don't know the environment the TS is going to house, and operate this unit.

E
 

Thread Starter

Stefi

Joined Jul 27, 2022
13
The terms you all are using are news to me, I tried to read into them as much as possible and will continue to try to learn about them. An rcd should be installed in my house but since I can't see any physical proof of it I searched for some pluggable rcd.

https://www.galaxus.ch/en/s4/produc...HKOcca4DYuhF8r-gUBUaAqEbEALw_wcB&gclsrc=aw.ds

Would this item be enough or do I need a bigger box like item?
Also the seller said that the submersible pump does not need earthing because it is well insulated. I highly doubt that it'd be wise to use a non earthed no brand device in water which will come in contact with my hands, would you also recommend to buy a seperate rcd for it too?
Thank you.
 

MaxHeadRoom

Joined Jul 18, 2013
25,630
Also the seller said that the submersible pump does not need earthing because it is well insulated. I highly doubt that it'd be wise to use a non earthed no brand device in water which will come in contact with my hands, would you also recommend to buy a seperate rcd for it too?
Thank you.
Not true in N.A. Even double insulated (no earth conductor) equipment require a CFI/RCD in this situation,
I assume it is 2-wire fed?
 

Ian0

Joined Aug 7, 2020
5,839
Okay, I will try to inquire more about rcd, I read that it is obligatory for every household since 2009 but the only distinguishable system belonging to the electrical grit is this dusty box, does it look familiar to you?
And also in other german forum I read that the electric is being shutt off whe the current flows where it shouldn't but that in this fraction of a second you probably could die. That made me forget any feeling of security using electrical products.
An RCD looks like this:
https://cpc.farnell.com/pro-elec/au...j-VBjUVMbCczJyZrfPedNRGJhDZVMOEsaAoWDEALw_wcB
Note the test button - that's how you would distinguish it from any other type of trip.
The main protection provided by the machine you bought is its metal case. That is what would have kept you safe in the years before RCDs were invented. The only part you can touch is connected to earth. If the insulation breaks down, current flows to earth through the case and blows the fuse.
If there also is an RCD then it will switch off at a lower current.
 

Thread Starter

Stefi

Joined Jul 27, 2022
13
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