X-ray Machine Tripping RCD

[s7t7e7v7e7]

Hi there,
First post so please be patient. I was called to our local vets as there X-ray machine would trip the RCD at the consumer Unit when they went to switch it on but when they re-set it it works fine as it only does this the once. I can not find any faults with the fixed installation and the x-ray machine has a current PAT test and is connected to a standard 13a socket via an IEC lead. I cant find any spec details on the machine which I must admit looks like it is from the 60's or 70's. The owner says it has been serviced but is reluctant to call them as they apparently charge £500 a go. So has anyone come accross this before or may have some idea as to why it only trips the once each time its switched on. I've been really busy lately so think i might just be missing something. I have also given the machine a PAT test and all readings within parameters etc. I dont have any real dealings with this type of machine and I'm not clear as to wether or not its even suitable to be on an RCD. Any help greatly appreciated

Many thanks

 

[Plonker 3]

Have you tried contacting the manfacturer direct or the company that serviced it for any info on the machine?

 

[s7t7e7v7e7]

Have you tried contacting the manfacturer direct or the company that serviced it for any info on the machine?

Hi there, just tried the company that serviced it but they were really lacking in any info so not that helpful and I tried to google the name on the machine but , well that did'nt really yield any further info but thanks for your input.

 

[Pete999]

Have you measured the earth leakage current?

 

[s7t7e7v7e7]

Have you measured the earth leakage current?

Hi there,

not as yet , but I'm popping in tomorrow so I will do one then. Also just had info back from the service agents who informed me that it should not trip the RCD so at least I know that the leakage current should be less than 3.5.

I will also unplug every other appliance except X-ray machine as not had chance to do this as they have been running lab analysing equipment on same circuit which they did not want to switch off at the time so I could be being sold a dummy and its not the x-ray machine at all. Its so easy to get sucked in to what the they tell you as it usually ends up being something else.

Thanks

 

[Pete999]

Hi there,

not as yet , but I'm popping in tomorrow so I will do one then. Also just had info back from the service agents who informed me that it should not trip the RCD so at least I know that the leakage current should be less than 3.5.

I will also unplug every other appliance except X-ray machine as not had chance to do this as they have been running lab analysing equipment on same circuit which they did not want to switch off at the time so I could be being sold a dummy and its not the x-ray machine at all. Its so easy to get sucked in to what the they tell you as it usually ends up being something else.

Thanks

3.5 mA? what size RCD ar you using

 

[s7t7e7v7e7]

Earth leakage current of the appliance. The RCD in the consumer unit is 30ma.
the 3.5ma of the appliance is what the service agents gave me as a miximum.

 

[Pete999]

Earth leakage current of the appliance. The RCD in the consumer unit is 30ma.
the 3.5ma of the appliance is what the service agents gave me as a miximum.

Right cheers, anything else on the circuit that could compound the total earth leakage?

 

[s7t7e7v7e7]

Thinking about it , yes it could be possible as there is lab equipment etc on the same circuit although this is mainly Computerised low voltage type. Also there is the X-ray developer as well so will check that. I will probably check everything as the more I think about it you never get the full story of what's exactly going on.

Anyway many thanks for your suggestion about leakage as i would think its definitely appliance related.

 

[DPG]

Thinking about it , yes it could be possible as there is lab equipment etc on the same circuit although this is mainly Computerised low voltage type. Also there is the X-ray developer as well so will check that. I will probably check everything as the more I think about it you never get the full story of what's exactly going on.

Anyway many thanks for your suggestion about leakage as i would think its definitely appliance related.

IT equipment can often have high-ish leakage current. Can soon add up. Specially if the RCD is tripping early. Daz

 

[telectrix]

as above^^^^. cumulative leakage is my educated guess.

 

[plugsandsparks]

could also be needing an RCD type A but manufacturer should be able to confirm type. cheers

 

[PEG]

Hi dude,have you confirmed it is the RCD that is letting go,and not an MCB? In which case, inrush current would be my guess on a device of this type and age.

Also,in all my years of dealing with vets,and i know many,i have yet to encounter a scenario,where one says "I can't afford that..."

Not seen one on a push-bike yet...:icon12:

 

[Engineer54]

First off any X Ray machine should always be on it's own circuit, whether fixed or mobile (with say 3 dedicated socket outlets) inrush current can be extraordinarily high.
If this is a mobile unit, i wouldn't be including any RCD in the circuit, any protection the X Ray machine needs will generally be incorporated within the machine itself. Lastly, DON'T go mucking about with this X Ray unit, leave it to the specialists. If i were to tell you how much the generator head costs for small mobile unit, (let alone a fixed unit), you'll be having kittens if it went bang and you're held responsible!! I doubt very much if your insurance will cover you in such as a case either...

 

[UNG]

I would certainly be checking and testing that the RCD is operating within spec before doing anything else no point going on a wild goose chase

 

[Leesparkykent]

Earth leakage current of the appliance. The RCD in the consumer unit is 30ma.
the 3.5ma of the appliance is what the service agents gave me as a miximum.

They have probably quoted you this figure because Stationary equipment with an earth leakage current exceeding 3.5 mA must be permanently connected, or a plug and socket to BS EN 60309-2 must be used.

 

[Geordie Spark]

as above^^^^. cumulative leakage is my educated guess.

An "educated" Scouser ....mg_smile: ... one who passed the 11 Plus at Approved School. :wink_smile:

 

[Geordie Spark]

Thinking about it , yes it could be possible as there is lab equipment etc on the same circuit although this is mainly Computerised low voltage type. Also there is the X-ray developer as well so will check that. I will probably check everything as the more I think about it you never get the full story of what's exactly going on.

Anyway many thanks for your suggestion about leakage as i would think its definitely appliance related.

If that developer is anything like the ones I used to service in hospitals it will have heating elements in it to heat the fluids and a fan heater to dry the processed print. All possible sources of earth leakage.

 

[Deleted member 72666]

Earth leakage current of the appliance. The RCD in the consumer unit is 30ma.
the 3.5ma of the appliance is what the service agents gave me as a miximum.

I like the sound of that word, somewhere between minimum and maximum......

 

[telectrix]

If that developer is anything like the ones I used to service in hospitals it will have heating elements in it to heat the fluids and a fan heater to dry the processed print. All possible sources of earth leakage.

the ones they make now ( since your time in 1930) connect directly to a computer with digital x-ray images.