Help wiring VFD controls

I posted some pretty specific questions on wiring the E-stop and controls on a UK spec 4KW single phase Omron/Yaskawa V1000 (same unit) for use on a woodworking chip collection system fan a while ago and got no response - perhaps because it's an EU unit there's not many familiar with.

Getting it wired seems to keep on throwing up more complications - initially it seemed to be just a hook up the power in/power out black box job. Maybe some more general input based on normal safe and (small shop) practical VFD wiring practices is possible??

There's three functions causing me some bother, in that there's fancy fault and safety relays mentioned in the manual which (a) are complicated for a mechanical guy, (b) expensive at about $150 each and (c) a cause of worry in that the installation needs to be safe and reliable.

The safety relay it seems is used when wiring E-stops to trigger the safe disable function. It seems like the relay delivers functions that are not needed in my situation, and that I can probably wire a simpler single n/c locking E-stop button to trigger the function (which stops, but does not power down the drive), and use the touch pad on the VFD to reset. (the fan is fully enclosed, and not a safety risk - it's more about protecting the motor and drive in the event of clogging caused by a bin overflow)

A fault relay (faults are a particular more serious category of alarm or error) seems to handle tasks like dropping out a n/o contactor in the incoming power supply (is one needed? - the plan was just to use a normal type C MCB to protect the drive/shut down the supply) in response to an internally generated digital fault output signal from the unit, or the switching of an external (?) thermal relay.

The thermal relay referred to seems to be the temperature sensor in the motor - I would like to hook this up for safety reasons, but think it can probably be wired simply by connecting it across the two listed terminals on the drive

The plan is to control forward run/stop fairly simply with just a rocker switch in the connection from a common output terminal to the relevant digital input terminal.

Speed (to raise motor rpm from 2850 to 3450 rpm - to compensate for our 50Hz power) and soft start setting (to control start up amps) are once-of commissioning tasks which can presumably be handled from the touch pad on the drive. Once these are set then forward run/stop is the only control input required, this seems to be just a matter of closing/opening a n/o switch (the rocker above). When not running the drive would if wired as described remain powered up, but it would be powered down when the shop is unoccupied (along with the circuits powering all of the other machines) when power is cut using the shop isolation switch.

Can anybody help by listing what control functions and protections are normally required in a basic VFD installation like this for it to be regarded as functional and safe?

How are the functions I've listed typically wired/controlled on a VFD in a simple workshop motor on/off installation? I'm hoping the fancy relays are overkill/manufacturers on the make/only required in more complex industrial environments vs. this one.

Thanks

ian

PS On the say so of the supplier I've used 6mm2 shielded cabling for both the single phase input, and 220V 3 phase output. Yaskawa suggest 3.5 - 8mm2, but both runs at 3m each are very short (the manual talks of runs of up to 100m) in my installation and the voltage drop at full load calculates using their formula as a tiny fraction of the permitted 2%.

Wow, it sounds like you are trying to make something very complex out of something pretty simple.

I wire my VFD's very simply. 1ph in then 3ph to the motor. Thats it.

Overload parameters are programmed into the VFD. If the current draw is over the programmed current the VFD goes into fault mode and stops. No extra relay is needed. The VFD just stops generating 3ph power until it is reset. I don't use any thermal overload protection... I just let the VFD handle the overload protection.

Also programmed into the VFD is the output frequency. If the VFD was made for the US market it will most likely default to 60hz. Even if the input frequency is 50hz the output frequency will most likely be 60hz... no extra parameters to set.

I use the panel controls on the VFD for start and stop. Remote controls via the VFD inputs might be nice in some places but for me Green Button on the VFD to start and Red Button on the VFD to stop works really well!

Why make it difficult if you don't need to? Especially for a saw dust collector?

I dont know ur model in detail but it sounds like u r reading the manual in detail and trying to follow the EU CE recommendations that large OEMs must follow to ship many many units to many many coproorate customers.....

I would suggest that for a home type shop u may not want to follow all these. do u wear eye safety glasses with side shields in ur shop all the time? steel toed shoes? whats that thing on top of your foot that needs protection - paranormal something?? wear those? prob not. If you answer no to any of these maybe u dont need to get careied away with super safety? I am not recommending u not do safe stuff mind u....

since u did not get lots of replied yet, I will give u my 2 cents worth on ur items below....l.

ondablade said:

.......The safety relay it seems is used when wiring E-stops to trigger the safe disable function. It seems like the relay delivers functions that are not needed in my situation

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CE (like our UL) requires a safety relay nowadays as I understand it.... this is a small relay that when energized removes logic voltage from the firing circuits of the output stages of the drive to allow Europeans to work on their motor driven stuff without removing the 3 phase power. Neat concept, but it is seldom used in the USA - we just dump the input power and then work on the motor. causes us often to have to rehome a machine but thats another story. I'd say u could consider ignoring this one.

A fault relay (faults are a particular more serious category of alarm or error) seems to handle tasks like dropping out a n/o contactor in the incoming power supply (is one needed?

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Hmmmm.... when we build a machine for a customer here in the USA we gotta cover our buts and so sure, we use the free fault contact that is provided. In ur small shop, if the drive breaks, I bet u will be right there using the machine and will say "Oh sh_t," and turn off the power urself. So, unless u have some sort of input contactor that u can wire this fault relay contact in series with, I'd say ignore it.

The thermal relay referred to seems to be the temperature sensor in the motor - I would like to hook this up for safety reasons, but think it can probably be wired simply by connecting it across the two listed terminals on the drive

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ur close but have it a tad wrong I'd guess. there are little relay things you can buy for around $ 200 that have bimetallic heater thingies inside that will open a set of auxillary contacts if they see more current flow than they are rated for - called thermal overload relays. if u DO add one as suggested, you gotta use the contacts somewhere again - so I bet u dont have an input contactor to drop out so again, this seems like a no brainer to ignore in ur small shop/garage case. If ur motor does have a thermostat, by all means hook it up to some input terminals on ur drive to give a bit more protection.

Can anybody help by listing what control functions and protections are normally required in a basic VFD installation like this for it to be regarded as functional and safe?

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so there is my 2 cents worth. that's my story and i stick to it!

Thanks, ian

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ur welcome Ian.

PS On the say so of the supplier I've used 6mm2 shielded cabling for both the single phase input, and 220V 3 phase output. Yaskawa suggest 3.5 - 8mm2, but both runs at 3m each are very short (the manual talks of runs of up to 100m) in my installation and the voltage drop at full load calculates using their formula as a tiny fraction of the permitted 2%.

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wow Ian, u did good following yet another OEM note! I know no one in a small shop who uses shield INPUT wire, and since u already bought the shielded output wire, use it. this is indeed very important to allow other sensative equipment like load cells, linear encoder scales, etc., to work on the same machine. I doubt you had any real need to use this shielded wire, but it doesn'.t hurt.