Looks a squeeze, 240 swa thoughts.

[Darkwood]

To be fair and I have touched on this, I would require a hell of a lot more info of Lee before designer the motor power supply, like I said, even something as simple as having speed control could change the requirements of the existing motor set-up and could require the need for force ventilation.
VSD - Motor cabling also has many factors to be considered here, the BS7671 is based on general cables and their common ratings and values, if you come away from these and go into specialised cabling with different insulation and sheath materials then it can open other options which can see reduction in CSA, I use IGUS and LAPP brands which can mean you have to forget the BS7671 charts and use the manufacturers guides.

 

[Andy-1960]

Darkwood, I agree the info is a bit sketchy and I have not had much to do with ATEX installations. It’s a very onerous minefield in my opinion!
One thing I do recall though is that I believe the VSD and the motor have to be a matched pair in order to comply with the regs.
Something else the OP should maybe look into as well as the requirement for insulated bearings that I mentioned in my earlier post.

 

[Darkwood]

@Andy-1960
You and me both - ATEX is not my field either so will leave comment on that side for others, I am interested in your matched comment, do you mean brand matched or motor is actually matched to the drive on a individual basis.. given the tech' now in VSD's I am somewhat confused by the matched comment?
As for insulated bearings, I was led to believe most modern VSD friendly motors were designed to limit/stop circulating currents through the bearings, agree if it is deemed to be an issue with this setup then it does want addressing.

 

[polo1]

This topic is outwith my experience, but it’s good to see/read knowledgeable people having a constructive dialogue about the possible issues and solutions.
Just sayin’!

 

[westward10]

I would assume matched to the motor and not by brand.

 

[Darkwood]

I ask because their is a certain brand out there that match their motors to their VSD's, I believe they program up the drives to account for certain anomalies in the frequency blind spots due to the design of the motor.. I have seen one of their motors run on another brand VSD and it just trips out and the motor gives some very strange HF noises out.
Modern VFD's can be taught or self teach about the motor connected, I just wondered why the matching ?.. unless it just means been pre-programmed up at factory as it can get complicated when using Vector, small errors in settings can have running issues.

 

[Andy-1960]

It was a project I was involved with a little while back. It involved extract fans within a refrigeration plant room. The refrigerant was ammonia so it was deemed to be an ATEX zone where the fan was sited, but the VSD was in the safe area. The consultant on the project said that the VSD and the motor had to be a matched pair if the VSD was running the motor during a leak. The work around was to by pass the VSD and run the fan at full speed from the mains when a leak was detected. Not sure of the reasoning behind the matched pairing, but it was definitely to do with the ATEX certification for the project. I will try and do a little more digging.

 

[cliffed]

Interesting to see how this pans out,does seem nearly impossible to connect that sized Swa into that box.
Help from motor company may be advisable,the last one I did we did 2 cables in parallel,thinking that was 2x35mm,easy .
The last time we installed 240mm x2 was for a recycling plant,terminating into main panel,that was hard work,but had enough room to make a decent connection.

 

[LeeH]

Wow, info overload...I’ll do my best to cover everybody’s input.

Motor 262kW 461A. It will run to its FLC, the smaller 30kW machine does so that has to be presumed so.

SY is no more an more ideal cable than SWA, the cores are not symmetrical and often the braid is terrible.

SWA is not ideal but symmetry is possible and is generally accepted as being sufficient. Especially when the ELV control is also SWA. The most important factor is the low impedance back to the chassis of the vsd from the motor which will be achieved on all the drives on the project by bonding from the motor frame to the containment as well as the supply armour, the thermistor armour and the cpc.

I know the most ideal cables are the foil wrapped with the 3 symmetrical cpc’s but I cannot run those types of cables in this environment on 900mm ladder.

Inverter location is fixed, I think I can get the route just below 30m.

Hot factory?? Ambient temp correction factor. 40 degC

I don’t see how I can use tri rated for a few reasons, EMC compliance, getting them in 2 M75 holes....

Darkwood, of the motor is pulling its FLC, and I do not have the knowledge to de rate the cables just through experience on something this large.

Forced ventilation is not required, the smaller ones runs 40~60Htz.

x2 120’s seems possible.

Thanks to all who have contributed so far.

 

[LeeH]

I understand Darkwoods Tri idea now by using an interface box and flexi conduit.
These drives do ‘learn’ the motor on a one time basis. They just turn them a 1/2 turn while measuring the windings and other things that are beyond me.

 

[Andy-1960]

I understand Darkwoods Tri idea now by using an interface box and flexi conduit.
These drives do ‘learn’ the motor on a one time basis. They just turn them a 1/2 turn while measuring the windings and other things that are beyond me.

ABB drive Motor ID run for DTC by any chance?

 

[Bobster]

Don't forget the thermostat protection an circuitry linked with the drive for atex requirements.

There aren't many vsds on the market you can just wire the motor thermostats and use it's inbuilt features to comply with regs.

 

[LeeH]

We have external Siemens modules that are certified in the panel. Seems schnieders top of the range drive excluded have this feature!

 

[satori]

Forced ventilation is not required, the smaller ones runs 40~60Htz.

The mind boggles when I try to imagine how forced ventilation would be implemented in an ATEX environment!

 

[Bobster]

The mind boggles when I try to imagine how forced ventilation would be implemented in an ATEX environment!

Pretty easily actually, why would you think otherwise?

 

[timbobelfast]

Most of the Draw-works on drilling rigs are by forced ventilation tbh.