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Interesting - why use an NVR switch when the box has emergency stop capability which will stop the motor quicker as it will ramp the frequency down faster than free run ? I don't see the need for an NVR when a 13A switched and fused outlet with an indicator light on it seems perfectly adequate and is smaller, neater and cheaper.

I do also seem to remember that you do have to go into the programming to set the box to Remote. There is also the case of maximum and minimum speeds that should really be set - few people will be aware that it is acceptable to run an induction motor, particularly multipole ones, at 100Hz or more whereas going much below 25Hz runs the motor into cooling problems.

Sorry Chas, on this one I don't agree with you and using these boxes without being aware of all the major parameters of induction motor running is inadvisable.

Rob
 
OldWood":349ioi74 said:
Sorry Chas, on this one I don't agree with you and using these boxes without being aware of all the major parameters of induction motor running is inadvisable.

Rob
That's fair enough, but there is not a lot of mystique involved with using them and personally have not had a cooling problem with the normal duty cycle associated with a wood lathe.

OldWood":349ioi74 said:
Interesting - why use an NVR switch when the box has emergency stop capability which will stop the motor quicker as it will ramp the frequency down faster than free run ? I don't see the need for an NVR when a 13A switched and fused outlet with an indicator light on it seems perfectly adequate and is smaller, neater and cheaper.
Now this is something I totaly have to disagree with, the NVR switch is to protect an operative from a machine starting up again after a mains supply power interruption without deliberately resetting it.

They are not fitted to just about any electrical powered machine tool you care to purchase for nothing, indeed I believe it is illegal to supply a machine without one.
 
Sorry chaps but I think my brain just imploded, (hammer) . I have a friend who is a fitter where there is alot of inverter usage on machinery, he is going to check everything I do. When you program an inverter to alter ramp up and ultimate speed of the motor is it reasonably easy or is it loads of code and things. Does the inverter have to be placed away from the lathe to protect it from dust, will I be able to use the existing on/off switches. The chap who is supplying said the variable speed is achieved by turning a dial, if the dial is on the inverter then it would have to be on the lathe. Or is that where the remote comes in. Does the remote just plug and play? or does it need to be programmed as well? Sorry for all the dumb questions and thanks for all the input.
 
wallace":6l2z5q7t said:
... When you program an inverter to alter ramp up and ultimate speed of the motor is it reasonably easy or is it loads of code and things.

Usually, after selecting the function number it's a matter of selecting the appropriate numbers on the display.

wallace":6l2z5q7t said:
...Does the inverter have to be placed away from the lathe to protect it from dust,
Idealy yes as it needs cooling. *

wallace":6l2z5q7t said:
...The chap who is supplying said the variable speed is achieved by turning a dial, if the dial is on the inverter then it would have to be on the lathe. Or is that where the remote comes in.
The potentiometer knob on the inverter is usually very small and not practical to use as the working control, it's intended as an easy means of adjusting the speed in a fix and forget mode.

wallace":6l2z5q7t said:
... Does the remote just plug and play? or does it need to be programmed as well?
No programing involved, once wiring is connected between remote box and inverter all you have is a couple of switches and a potentiometer knob to turn.

* On my main lathe the inverter is mounted within the headstock away from the dust and gets its cooling by direct mounting of its heatsink on the cast housing,
 
Now this is something I totaly have to disagree with, the NVR switch is to protect an operative from a machine starting up again after a mains supply power interruption without deliberately resetting it.

They are not fitted to just about any electrical powered machine tool you care to purchase for nothing, indeed I believe it is illegal to supply a machine without one.

I stand corrected ! And actually went out to the workshop to see what the box did on a mains failure. Really suprisiing - I did expect the electronics to be sensitive to that and shut down. An NVR it is going to have to be then - thanks for alerting me to that. I'll have to look at the other installations I've done for friends now.

Cheers
Rob
 
Firstly, I gather that this machine is not to be used in a business?
If it is for business use then a radical re-think is required.

I’m now going to make a few comments and statements that may not be popular, however, this is what I do for a living and I am doing OK at it thanks, I’m far from the cheapest at what I do, but my customers return.
That is I put my money where my mouth is & get paid for it and I go back again so I must be doing something right!
Remember being an engineer I am paid for my opinions and only when they are proven am I correct.
As per my sig, I actually also provide control systems design and H&S advice & carry the PI insurance for this.
Please note carefully that my comments on this forum are not and cannot ever be taken as formal engineering or H&S consultancy advice.
I use the term inverter generically, to mean variable frequency drive or pulse width modulated drive etc.

Inverters can do many things, they may work with the default parameters on any particular motor, they may not, they are not clever enough to "read" the motor data unless this is programmed into a chip within the motor and communicated to the drive when they are connected and powered up, we used to do this with our digital drives to prevent customers (machine builders) from running drive & motor combinations outside their design parameters. Some can make very rudimentary impedance measurements (inductance, capacitance and resistance).

I believe that the price of £200 is very cheap, the guy is doing himself no favours, especially when he considers the risk he is taking in providing you with his professional opinion on how to make this work should it go wrong.

Any inverter unless IP65 rated will need to be fitted into an IP65 rated enclosure with sufficient air space and thus cooling to prevent the unit from overheating. Remember these devices will have loads of electrolytic capacitors in them, they don't like heat.

Any machine used in a business undertaking or sold, must have a nvr or "equivalent" method of safety.
It is doubtful that an inverter would restart a motor after power loss.
However, its suitability for use as the nvr on a machine would need to be clarified by the manufacturer statements.
Any emergency stop device must be latching in the off position else it is not an emergency stop.
Any start device must be momentary, i.e. only make the contacts when pressed and break them when released.

You can wire a suitable remote potentiometer of a suitable value in a suitable manner remote from the inverter for speed control at the operating position for the lathe, if the inverter has that facility

Inverter ramp functions can be very severe, you need to consider the machine mechanics before ramping too fast. Think about how quick it ramps up on a standard squirrel cage motor on 50Hz mains and make the ramp down the same time.

Most programmable inverters have several responses to e-stop commands. They can free wheel, ramp down at max ramp or at a programmed ramp, at ramp up speed and others.

CHJ is correct with the mains filtration. Inverters can inject harmonics and other such electrical “nasties” back into the mains, this is no longer allowed under statutory legislation and you must install an RLC filter at the input to the drive.

Also remember that you have a statutory legal duty to inform your electricity supplier/local distribution network operator if you are connecting loads above a certain value to your domestic electrical supply.

Adding bleeder resistors and other such drive additions can get quite complex, remember bleeder resistors can get VERY VERY hot in a VERY short space of time, the consequences of this could be interesting! Keep them in a dust free environment & I mean FREE, where they can dissipate the heat, their rise is almost adiabatic for those that follow my train.

Again an out of the box inverter set up may well work OK as CHJ suggests it may not. This may depend on many things including the number of pole pairs in the motor, most are targeted at 2/4 the OP has 6 so tweaks may be needed?

Transforming up voltages is one way, however, remember that the current on the primary is also increased! You don’t get owt for nowt!

To add a remote control panel and remote speed pot should only be a couple of parameter changes.

You need to be careful in supplying your inverter from a DOL type starter which is what I think CHJ refers to as an nvr. Please consult the makers documentation as you may need separate supply controls devices for the control circuits and the power sections.


OldWood is correct that the max speed must definitely be set and the min is advisable, the overheating comment is also correct, again please remember that wood dust and especially wood flour is extremely flammable nay even explosive.
The issue with overheating may as CHJ states be a small risk due to the duty cycle, but it is there. The airflow across the motor fan of the induction motor will be designed to keep the motor temperature within its design limits when running at full load according to its duty cycle at its normal running speed. This is a common failure mode when inverters are incorrectly applied to induction motors in industry, this is more common than you think!

It is illegal to supply a machine or in fact any motor driven device for business use without an “nvr”, however their application in DIY equipment is a mute point, the number of DIY machines I find in business premises that do not comply with PUWER98 due to the lack of nvr is astonishing!
I condemn them and write up a report.
I actually rung and demanded an answer from one “cheap” machinery maker with 3 letters in their name and asked them if any of their machines met the requirements of PUWER98 after going through a few of their technical support guys who did not understand the question, once I got through to one that did, he could not answer me, they had to call me back the following day with an answer from elsewhere in their organisation which was, guess what, NO!

Wallace, if he is a fitter he may not understand the full ramifications of the electrical systems. His work may be primarily mechanical, it may not, you need to be sure that he has sufficient electrical competence as his errors may end up hurting you even though they may be unintentional, in fact they will almost definitely be unintentional!

A BS1363 plug & socket is acceptable for isolation for emergency use and for mechanical maintenance according to BS7671 (IEE wiring regs).
Please remember if you mod your own machine then this may be fine, but "IF" "something" "goes wrong" and your house insurer becomes involved, in say a fire, then if the equipment does not meet accepted standards and good workmanship then you may have issues with them paying up.

Now, don’t be afraid of doing these things, just do them right, research, ask questions, follow the makers instructions, and the relevant UK standards & guidance you will be fine.
Remember though your biggest enemy apart from the electricity itself, will be the very thing you are working with the wood dust!

Sorry if I have upset anyone, but this peeps is the way it is!
 
Paul
Your input is from someone who is in the professional world. I think you are incorrect in raising all sorts of ghosts for the amateur and DIY environment - I consider that you are scare mongering, perhaps not deliberately, but because you take your job seriously and think that what applies there, applies to us all. It is not fair for you to quote PUWER98 at us - these are regulations for the work place and do not apply elsewhere, OK it might be that they represent good practice, but it certainly isn't the case for instance that insurance companies could penalise a homeowner for not complying. We are under no obligation whatsoever to ensure for instance that our bandsaws run down in 10 seconds, that our circular saws have all the protection covers; these may be desirable, but beyond that nothing. We have no one to sue if we damage ourselves and that is the key point. 20, 30, 50 years ago the loss of a finger was regarded as a hazard of the job and you lived with it; now in the litigious age, every company has to make sure they cover their a****s, and that is where you come in. Please stop the lecturing - it's not helpful.

Apart from the standard wiring regulations, there are no safety regulations that apply to the homeowner - Chas has pointed out for instance the significance of the DOL/NVR, but I am no obligations in terms of the law, or in fact the insurance company, to comply.

Rob
 
i have taken that motor apart. . my power plant was the single speed 1.5 hp.( wadkin did offer a two speed motor with two windings) with a VFD. i will get better speed control ,forward and reversible,and breaking. the motor that came with the lathe is 550 volts so i had it rewound with inverter duty wire. for those at home this cost me $300 plus the VFD of about $200. there is no motor swap here as this is a special motor. so for $500 i will have all the features of a modern lathe. while the statorwas at the motor shop i got bearings and painted the end bells and get it ready.

motor004.jpg

motor005.jpg

motor006.jpg

motor007.jpg

motor008.jpg


ok so you have done a few motor bearings, and you run into some hoffmann . they are open deep grooved and have bronze cages. you do what any self respected wood worker would do and call the bearing shop.he sayes she will have to get back to you and you don"t hear from him for hours. you have givein him all the info the sizes. bang the phone rings and she has found them. they are not cheep. as they would say i am loking for good bearings cheep, not good cheep bearings.
one of the bearings was a little worn but i got two @ $82 each. they are open with a bronez cage.

bearimgs011.jpg

the stator was at the motor shop being rewound to 220 volts,with inverter duty wire. as i said the the motors bearings are being shipped during this. so as far a the power plant goes all i needed was VFD. i went with a Teco 7300 cv . it has the power switch for the vfd , with forward and reverse,start and stop with two station one with a cable and magnet to locate the station down the bed or on the out board banjou, . What i like about this unit is the control pad is removable and can be remote of the vfd.

vfdsvector.jpg


i pulled the bearings from the rotor and i am looking forward to getting the new ones.

bearings001.jpg



the bearing caps or grease caps for the motor bells are made of aluminum cast . one of the caps had been damaged and was missing the grease zurk. so i had to fix one on. i solder a peace on and am good to go.

bearings003.jpg

bearings004.jpg

it need to be that long b/c of the pulley at that end covers the grease cap.
bearings007.jpg



i got the bearings ,and the motor back from the rewind shop. we painted it and put it together. as i said we rewound from 550 to 220 so i can run it on a vfd.

vfd001.jpg

vfd002.jpg

IMG_0011.jpg


these are open bearings and need to be greased. i used synthetic EP.
IMG_0013.jpg


the guys at the motor shop did a nice job of the rewind with invertor duty wire.
IMG_0010.jpg



we put the long shaft end on first.
IMG_0015.jpg

IMG_0016.jpg

IMG_0019-2.jpg


i wire it up for a test run. and shot a video.


jack how will now field questions
 
NetBlindPaul":2ruyl0yu said:
.........It is doubtful that an inverter would restart a motor after power loss.

The IMO Jaguar Cub inverters I have (also sold under several other brand names I believe) start to ramp up power output as soon as power is supplied to the input if the rotational direction switch is made or equivalent link is in place.

The only time they will not start as such is if the Invertor has tripped on over current due to the motor being stalled with a severe tool catch and is going through its built in cooling/safety routine. *
They will not start up again until power has been disconnected long enough for internal circuits, capacitors/interlock circuits I presume, have had time to discharge despite them showing power as still connected to the input.

* A very good safety attribute as far as I'm concerned, happens rarely but very thankful when it does.
 
OldWood":1gxarlwl said:
Paul
Your input is from someone who is in the professional world. I think you are incorrect in raising all sorts of ghosts for the amateur and DIY environment - I consider that you are scare mongering, perhaps not deliberately, but because you take your job seriously and think that what applies there, applies to us all. It is not fair for you to quote PUWER98 at us - these are regulations for the work place and do not apply elsewhere, OK it might be that they represent good practice, but it certainly isn't the case for instance that insurance companies could penalise a homeowner for not complying. We are under no obligation whatsoever to ensure for instance that our bandsaws run down in 10 seconds, that our circular saws have all the protection covers; these may be desirable, but beyond that nothing. We have no one to sue if we damage ourselves and that is the key point. 20, 30, 50 years ago the loss of a finger was regarded as a hazard of the job and you lived with it; now in the litigious age, every company has to make sure they cover their a****s, and that is where you come in. Please stop the lecturing - it's not helpful.

Apart from the standard wiring regulations, there are no safety regulations that apply to the homeowner - Chas has pointed out for instance the significance of the DOL/NVR, but I am no obligations in terms of the law, or in fact the insurance company, to comply.

Rob

Rob,
My opening line I hoped, covers my comments, in that IF the machine is in use in a business undertaking then the business "rules" apply.
If this was not the case then sorry.

However, have you read your home insurance policy small print recently!
These companies have been hit hard by the global financial crisis and are looking for get out clauses not to pay claims to reduce their outgoings.

You may find that there are clauses in there which they will use “on” you if you had an issue relating to a fire originating in a machine you had wired/built/modified.

Apart from that, I am trying to make the point that for example a bleeder resistor could have a temperature rise of perhaps in excess of 100 deg Celsius in less than one second, now that could be an issue if you were touching it, or it were covered in wood flour could it not?

I am NOT scaremongering, I hoped to make that clear with my closing comment.

What I was trying to do was to put some facts down with regard to the engineering science, from an inverter manufacturers point of view, my last employer prior to my own business was with such a company on design/applications/service.

I feel that much of my post does have relevance to the DIY use of these devices.

It seems to me that there is a mixed bag of posters on here, some are DIY some seem to be running business ventures, unfortunately, all H&S legislation applies to businesses even sole traders it is just the complexity that varies with the size of the business. Am I incorrect? Is this a completely and wholly DIY forum, as it does not seem to be from some of the web sites I have looked up?

I hoped also to show obviously not well the rules that apply to businesses, i.e nvr, e-stops PUWER98 etc.

IMHO you would hope that one would fit some kind of emergency stop device when modifying a machine even for ones own use as in the event of an unforeseen incident you may be on your own at home (?) and the big red button may be the one that saves you!


I do make customers laugh, sometimes, as I have 2 sayings I use on them about safety “devices”!

The e-stop is the only button on the machine that matters, the green one only makes it go, and that is not really important as the big red one is the one that makes it stop when you need it to, now that is important!

The only wire that is important is the earth wire as that is the one that stops you from getting electrocuted, the others only make the machine work and in comparison they are pretty unimportant really, are they not?

If you want I’ll just leave the forum, no problem.
I contacted the mod team on joining and made them aware of my status and I was told that I would be monitored. This I expected & I believed was wholly right.
I have never hidden my status in the industry, which is the major reason for putting the information I have in my signature, thus it is obvious to all readers of my posts my background.
I have not yet made any approaches or attempted to ply my wares to any poster, I have attempted to move machinery for posters on to my trade contacts however, I have made it clear to them my intentions I did this in an effort to help them.
 
CHJ,
I don't like Jaguar/IMO Cub inverters, my value engineering comments come along again.
I don't think that this modus operandi is correct and the inverter should have additional control devices fitted over and above a direction switch!
Normally the direction control would be via a contactor, thus, this would default to off in the event of a power failure, I don't have any manuals to hand for these right now.
"Our" inverter manuals did not allow a direct switch connection to the direction outputs, we also had a drive enable command, think dead mans handle before the drive would run up.
There are ways of implementing control on these devices quite simply to get red hot systems!

However, it seems I'm not welcome!
CHJ, sorry but it seems you may have been wrong. Sorry.
 
tool613,
One last comment, even if I rebuild machines with grease nipples on motors I never refit them!
I remove them and plug the holes.
Just because you had Hoffman open bearings in the motor did not mean you had to refit them.
I almost exclusively use 2RS bearings in motors and most wood machines.
The rubbing seals (RS) offer additional protection against the ingress of wood dust, also the bearings have sufficient lubrication within them to last what is called the L10 life, this is the design life that if the bearing is utilised within its design parameters that 90% of bearings will survive to.
This will be 100's of 1000's of hours at least.
One of the largest failure modes of electic motors is overgreasing of the bearings.
Your pic of the greased bearing looks well over greased to me, sorry, unless that is all the grease you have put into the unit.
By the way did you wash the bearings prior to fitting as they may have had a protective coating, or an incompatible lubricant already within them?

Apart from that well done nice job, I do like rebuilidng motors myself.
 
The jaguar inverter I have fitted to my wood lathe has an option to 'power off' mode which then requires an external command to power up, but in it's default state it is Power on.
Jaguar.jpg
 

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CJS,
IMHO the alarm output contacts must be wired into the e-stop circuit end of.
Thus these would assist in removing power in the event of a fault condition and as they should be wired through a contactor in the event of a power failure they would stop the MC from engaging, thus prevent restart.
I don't know the model etc. still so I can't fully comment, but, I would like to know what x1, x2, & x3 functions are by default.
I suspect that you have not correctly implemented the control / e-stop chain on your devices.

However, as it appears that my input is not welcome here I'm not sure if I'll be back.
 
NetBlindPaul":3b4ff2y8 said:
Just because you had Hoffman open bearings in the motor did not mean you had to refit them.
I almost exclusively use 2RS bearings in motors and most wood machines

as you may know Hoffman bearings are no longer around. these a skf
NetBlindPaul":3b4ff2y8 said:
The rubbing seals (RS) offer additional protection against the ingress of wood dust, also the bearings have sufficient lubrication within them to last what is called the L10 life
i like open over sealed in fact i have pulled seals off some . sealed bearing are guarantied to fail open just need some cleaning and greasing and clean out of the grease cap to make room. i have never found good old sealed bearing, but i have found good old open.
NetBlindPaul":3b4ff2y8 said:
One of the largest failure modes of electic motors is overgreasing of the bearings.
Your pic of the greased bearing looks well over greased to me, sorry, unless that is all the grease you have put into the unit.
lots of room for grease in the bearing caps and the bearings have be turned to remove the grease after packing. about 30% full .the pic is before turning and cleaning . good eye.
NetBlindPaul":3b4ff2y8 said:
did you wash the bearings prior to fitting as they may have had a protective coating, or an incompatible lubricant already within them?
looked like oil that most are packed in and i cant see that ever giving me a problem. the grease is a synthetic type EP #2 .

are you guys that regulated about a 1.5 hp motor over there?


jack
 
NetBlindPaul":3ss9xxff said:
I don't know the model etc. still so I can't fully comment, but, I would like to know what x1, x2, & x3 functions are by default.

if i was to make a guess they are preset for speed/ hrz out put. my 7300 cv has this.
i have wire my 7300 cv with a rotary switch and have set parameters to tell me rpm at the spindle when the mechanical drive is changed.(wish i had 4) my vfd will display proper rpm at the shaft. the LED display can be set to show rpm, amps have to look in the manual for others.

my vfd is also set for top end of 90hzs so that hp is not lost the wadkin rs motor is slow speed i believe over there 960 rpm.
jack
 
OldWood":2utg06xo said:
Paul
Your input is from someone who is in the professional world....

Apart from the standard wiring regulations, there are no safety regulations that apply to the homeowner - Chas has pointed out for instance the significance of the DOL/NVR, but I am no obligations in terms of the law, or in fact the insurance company, to comply.

Rob

Rob:

I'm sure you're correct about the difference between business rules and what a homeowner needs to comply with. However, some of what Paul is talking about (such as not letting an inverter restart a motor after an external power failure) is certainly applicable in all situations and could often be applied with very little effort. Yes, perhaps Paul is being a little abrupt, but having been reading this list for a few months now it's clear that both commercial users and hobbyists come here, and some of them (especially the new professionals) may not be up to speed on all the requirements. Engineers aren't known for being the, ah, smoothest communicators (though they're still a lot better than computer programmers like me). I think if everyone took a step back and reviewed their posts with the intended audience in mind before hitting the send button, we'd all enjoy the conversation a little more.

Paul, perhaps some more precise phrasing would allow the general audience to better discern what they must do from what they should do and what it would be nice to do.


CHJ":2utg06xo said:
The jaguar inverter I have fitted to my wood lathe has an option to 'power off' mode which then requires an external command to power up, but in it's default state it is Power on.

Chas, are you saying that your lathe motor will restart if you have an external power failure while running, then the power comes back on? If so, does that seem wise to you?

Thanks, though, guys, I'm getting a lot out of this thread.

Kirk
 
Chas - I initially wrote a challenge to your Jaguar's wiring diagram as I failed to pick up on the fact that 'MC' is 'Magnetic Contactor' - better to find these things first before showing ignorance. :roll:.

I don't know about the Jaguar, but the Teco 7300 CV I have can be set to switch off if there's a mains failure - I've checked my records and it isn't set correctly for this (one of today's tasks !). Do I take it that that this would not be considered adequate and that the NVR is not just belt-and-braces ?

It's also interesting to note that like my Teco, your diagram shows remote control switches are not momentary action. I agree with Paul here that momentary action switches are preferable, and are required by an older inverter I have. There's presumably some technical reasons why the designers have changed this.

Jack - I'm interested in your comment about getting an rpm readout from the 7300 - how is that achieved? Having looked at the manual I guess it must be something to do with Parameter 4.04 but how is that set up and implemented ?

Rob
 
OldWood":1x5epq4o said:
Jack - I'm interested in your comment about getting an rpm readout from the 7300 - how is that achieved? Having looked at the manual I guess it must be something to do with Parameter 4.04 but how is that set up and implemented ?

did it over a year ago, but all i did was call Teco and they walked me through took about 15 minutes a three position switch is all that is need.. i found them to be very helpful.just give them a call.

here is a test run on YouTube.
http://www.youtube.com/watch?v=WKr6lFud1g0





did the testing before i mounted it in the lathe.
IMG_0388.jpg

IMG_0389.jpg


i had bundled all the control wires for function and to keep this organized.
IMG_0403.jpg


the hole is for a pot and wires 9,10,and 11 wire it up. i had found the the pot was faulty.
IMG_0401.jpg


there is still room for dust collection controls ,and the flex conduit is for a control station with earth magnets . this will let me place a station at the other end of the lathe or on the outboard banjo.
IMG_0405.jpg


the center switches control power to the vfd and the stop has lock out for tool change. the switches to the right control the vfd that is mounted on the wall. the bottom switch is for speed control

.
IMG_0406.jpg


thanks for looking

jack
 
kirkpoore1":38hg3zmx said:
Chas, are you saying that your lathe motor will restart if you have an external power failure while running, then the power comes back on? If so, does that seem wise to you?

Thanks, though, guys, I'm getting a lot out of this thread.

Kirk

No Kirk, the inverter is downstream of a reasonable quality NVR switch and will not start up again until the NVR is activated.

Regarding comments elsewhere about lower budget end inverters I find that the IMO Jaguar Cub series quality more than adequate for my use, the one fitted to my wood lathe has been in use for 14 years.

An whilst we are talking safety with these devices, please remember that if dismantling a machine or control box for servicing that disconnecting mains power does not provide an immediate safe condition, dependant upon output connections and the model design parameters an inverter may still have a high voltage present on its terminals and any connected wiring for several minutes.

Best wait at least five minutes even ten before handling.
 

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