Dental x-ray machine

[Sidewinder]

Been asked today to quote for provision of a 230V supply for a dental x-ray m/c at local surgery, also, to run in control cable between m/c & timer/controller.

Supply OK, running wiring etc. all OK.

HOWEVER, spec / manuf. Inst. calls for no cpc in the control wiring and all info at this stage points to this being 230V, and it also requires flex rather than T&E.

Not too happy about the flex running through the trunking and loft space from wall to wall, but can't really find a reg. that prohibits it. It just seems wrong. Especially with no cpc if it is 230V. If it is F/P/SELV then I would have no issues. I will check with the UK agents tomorrow, it is a Japanese machine.

Just looking for other opinions on the cpc issue and running flex in the fixed install.

As I say it just does not sit right with me and it looks like the equipment connections may not take T&E from the info I have, again I

 

[Lee321]

hmmm i think your right about no reg on flex length although i have tried to practice 3m max over the years.

why you say concerned about no cpc with the flex i can't think of any reason why you would need one! ?

are you sure that they are indicating an omission of cpc rather than not mentioning it as its a matter of course that a cpc WILL be installed along with the required cores for operation

 

[Robojin]

Is this not wrapped up in the regs relating to Hospitals, I vaguely recall something about Hospitals running a different earthing arrangement

 

[green-hornet]

Most common Japanese x-ray are Belmont PhotexII or phopxII if it is this model the supply is 230v with cpc and the control wiring is cat5.

If you let me know the exact model I can help you, been there and done it as they say.

 

[Sidewinder]

green-hornet,

It is indeed a Belmont phot-X II! Model 303

However, the info I have been given so far indicated a 4 core @ LV.

It did not seem that way from the manuals, but, the info given by the "engineer" to my customer stated that it was!

So if it is CAT5, I can't run this in the same MT as the mains can I as it is not sufficiently insulated is it.

Also I have been given a spec that says the wiring must come in through the same entry point.

The "engineer" has asked for plain 4 core flex for the control unit.

Now if this is comms signals and has by its nature to share parts of the run with the power then what about cross talk?

I must confess I've never installed a supply for an x-ray machine before!

I am trying to get this as there may be another 3 and a full periodic which I could do with at the moment to follow this.

Price is not critical, quality of workmanship, keeping the place clean and tidy while I work, and minimum disruption is high on their agenda as they want it done during working hours, and only this single surgery will be out of action for the work to be done!

Main problem I can see so far is that I have to access the attic space. the ceiling is 10 - 12' up. The trap door is in the middle of the corridor between reception, and the toilet, dirty room and a working surgery!

I can see myself getting left up there when someone takes the ladder away!

Flex run will be around 12m, it's either run it in flex all the way, or change to something else part way and add in a joint, which is not good. By the sound of it T&E will be no use as solid cores are not good with HF signals if they are comms signals, skin effect and all that.

I wish I had the full spec rather than hearsay!

Suggestions appreciated.

Ta,

 

[green-hornet]

Just trying to get you the installation manual, they have them on line but I can only find the American one.

What we do normaly is put a fused spur outside the controled area like near the door, and then the control panel beside that. From the control panel we run cat 5 to the head. The terminals for connection are data type so if you run it in flex it would have to be very small. The cables need to come out 1.4m from the floor

You can try searching for a manual

dental.takarabelmont.com

http://dental.takarabelmont.com/downloads/

 

[Lee321]

do you do a scope of works?

if so you schedule the cat5 or flex which ever you decide the engineer is suggesting you use then that way if you install cat5 eg and it needed to be flex then its all in black and white what you interpreted the cable type need.

however they should approve the scope before works so it should be covered before hand

 

[Sidewinder]

green,

Have the manuals perhaps I need to read them!

Lee,

Writing the scope of works now hence the post!

 

[green-hornet]

do you do a scope of works?if so you schedule the cat5 or flex which ever you decide the engineer is suggesting you use then that way if you install cat5 eg and it needed to be flex then its all in black and white what you interpreted the cable type need.

however they should approve the scope before works so it should be covered before hand

Never tried to get flex in them connectors. Use cat 5 all the time. The engineer may actually mean cat5 or someone has misinterpreted him.

 

[Sidewinder]

green,

OK however, I've always been told and have always kept cat5 seperate from mains.

How can you run these together and meet the requirements for insulation for different category cables.

Can't be ar**d to look up the reg sorry!

 

[green-hornet]

green,OK however, I've always been told and have always kept cat5 seperate from mains.

How can you run these together and meet the requirements for insulation for different category cables.

Can't be ar**d to look up the reg sorry!

:^O

We normaly do refits so we put all cables in seperate conduit or mini trunking,

most of the time, as long as the main run is seperated its ok they still enter the head at the same point.

 

[Sidewinder]

This is not a full refit, just adding a single machine into a functional surgery!

So I may have to run 2 seperate runs of MT?

 

[Lee321]

as above. the problem is long lengths of mains and comms and not a few inchs as it enters a device with only 1 entry

 

[Sidewinder]

Lee,

Not in my previous experience though, hence my issues.

I have had loads of industrial comms issues with signal and power running parallel for only a few inches!

Please remember I've had loads of previous issues with screened power & data cables for synchronised motion and control applications where there were high power and high data rate cables in close proximity which could experience significant cross talk over very short distances!

 

[Lee321]

yes side i guess you have it on your mind then.

where as most of us having only done modest power and comms have never had a issue

your not going to have huge magnetic fields from high power in this instance

 

[Sidewinder]

True, 6.6A according to the manual!

It's just 20 years of industrial machinery employed by equipment manufacturers doing machinery, servo's, variable speed drives, cnc & plc, etc. with position & speed feedback has an affect on your mentality!

 

[Lee321]

 

[aptsys]

Not too happy about the flex running through the trunking and loft space from wall to wall, but can't really find a reg. that prohibits it. It just seems wrong.

There's no issue with using flex for fixed wiring - why would there be?!. You could do a whole installation in flex if you wanted to.

 

[Lee321]

There's no issue with using flex for fixed wiring - why would there be?!. You could do a whole installation in flex if you wanted to.

because if you read the terminology flex is flexible i.e for a flexible installation

where as t&e or 6491x for example is for a fixed installation :innocent

 

[sparkytim]

BRB Pg 98 521.9.3