Huge Reflow Oven in US, need to power in UK - Page 1
Forum section: electronics / general

author: CM800
author_rank: Frequent Contributor
timestamp: February 01, 2014, 01:30:31 pm
content: Hello everyone... i have a problem,My Friend's company needs a large Reflow Oven.We have found the right one for the right price, the problem is, its in america.the power input is rated as:480 Volt - 60HZ - 3 Phase - 74AIs there any way we could likely set it up and modify it for operation on UK Power source @ 3 PhaseThanks,TCW

author: cybermaus
author_rank: Frequent Contributor
timestamp: February 01, 2014, 01:44:13 pm
content: Depends how much you are willing to modify:Its an oven, with 99% certainty resistive heat elements, so 60 Hz won't matter much. Maybe do check the control electronics, but that is probably also not an issue, as those are likely behind primary switched supplies.Simplest and surest method: get a 3 phase step up transformer 400/408V to 480VAlternative method: disconnect control electronics and give it their own power supply (depending on what they need, 12V, 24V whatever), and hook the 480V elements straight to 408V.Assuming resistive elements, power will be about 75% of rating, so the oven will be a bit slower.

author: CM800
author_rank: Frequent Contributor
timestamp: February 01, 2014, 02:07:49 pm
content: Thanks for the info, this will be very helpful, i shall be investigating it in deeper detail.Thanks,TCW!

author: nctnico
author_rank: Super Contributor
timestamp: February 01, 2014, 02:19:41 pm
content: I'd consult the manufacturer to be sure.

author: cybermaus
author_rank: Frequent Contributor
timestamp: February 01, 2014, 02:32:00 pm
content: Well, actually yes.I missed it at first, but its 74Amps. Thats 61KW. I read big, but I did not realize that big.You probably want to get a proper industrial installation bureau involved. Wiring for and switching and dealing with cos-phi power factor (if you go the transformer route) is not quite the same at those levels. Its not as if your local hardware store will have the required relays on a shelf anyway.

author: CM800
author_rank: Frequent Contributor
timestamp: February 01, 2014, 02:41:39 pm
content: We are on a fairly tight budget as my friend's company is paid for more or less out of pocket.I don't believe it likely will be too hard to modify... will it?

author: cybermaus
author_rank: Frequent Contributor
timestamp: February 01, 2014, 03:06:40 pm
content: It may not be hard, but its high current, industrial, and its about a company (with employees?)Insurance, utility company, and liability may require it to be rated and approved.Also, it may not be too difficult, but of that you can only be sure if you know its components and how they are wired. And the mere fact you need to ask may indicate you may not be the correct person to judge. I still stand by my original idea it can probably be modified, but (as suggested above) start by asking manufacturer, if not for advise or confirmation then at least for schematics , and have a professional look at it.

author: IanB
author_rank: Super Contributor
timestamp: February 01, 2014, 05:11:45 pm
content: I'm pretty sure with something of that size you will need an industrial electrician to install it. At a minimum you will need a dedicated circuit and switchgear for it. Then since it is a non-standard voltage you will need a dedicated supply transformer to step down the 11 kV distribution voltage to the 480 V you need. This will involve the electricity company. I'm afraid it all smells very expensive. If you're lucky the unit might work on the UK 415 V 50 Hz three phase supply and then you won't need the transformer. You'll need advice from the manufacturer about that.Also, shipping a big heavy item from the USA to the UK will not be without its own costs.

author: sacherjj
author_rank: Frequent Contributor
timestamp: February 01, 2014, 06:04:43 pm
content: You don't play around with 480V. I have a friend that works at a manufacturer where they had a 480V flash when enabling power after replacing fuses, without scrubbing the panel. Enough excess carbon to give the person 2 degree electrical burns. When we installed large current monitors for our printing presses, the electrician needed to suit up in a flash suit to disconnect power. It is very easy to quickly get very dead.We installed an injection molder that uses both 480V and 230V. Similar in load to an oven, but using more power for hydraulic pumps than heating elements. Power electronics is generally OK with 50 and 60 Hz at the right voltage. Many also will run OK with 10% variance of voltage. So 220V works in our 208V from 3 phase 120V.IF frequency is not a factor, you can install a transformer for going up or down. It isn't cheap, and cost dependent on KVA. However, it was cheaper to get our 230V from existing 480V, then running 200 feet of the amperage gauge we needed.

author: CM800
author_rank: Frequent Contributor
timestamp: February 01, 2014, 06:28:42 pm
content: Yes, i understand....Its a big issue, i know my way around a fair amount of electronics, i had my own ideas on how to set it up following along with other ones posted,Cost is a huge issue, we can not deal without this equipment, this is a starting up company and its funded out-of-pocket... with the machine costing £5k, freight probibly adding £2k or more to it...the problem is there are zero reflow ovens in the uk for second hand sale... we can't find the cash to pay for a new machine (around £100,000)Then taking into account how much the electricians would charge...Would it be cheaper to do the course myself so i can maintain and install... or just hire expencive electricans to do it for me?

author: amiq
author_rank: Regular Contributor
timestamp: February 01, 2014, 06:44:10 pm
content: This shouldn't be a problem. Check if 50Hz operation is an issue - if it is you will need to buy an inverter to suite. If 50 Hz is OK check if 415V is acceptable, if not you will need a custom wound transformer - that won't be much more expensive than a stock unit.

author: CM800
author_rank: Frequent Contributor
timestamp: February 01, 2014, 06:48:29 pm
content: Found one in uk for similar price that isn't on ebay....what kind of cost would such a course cost so i could install it personally?I could install it myself easily enough, but as we may hire employees, its best to have the paperwork to keep the powers that be, happy.

author: IanB
author_rank: Super Contributor
timestamp: February 01, 2014, 06:55:41 pm
content: Quote from: TCWilliamson on February 01, 2014, 06:48:29 pmHow many such items have you installed previously?There is no comparison between a 100 kW three phase industrial circuit and a domestic mains installation. The industrial supply has enough energy to cause an explosion and kill people by turning them into charred pieces of meat. Don't even think about going near it if you don't have appropriate training and experience.

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: February 01, 2014, 07:00:22 pm
content: Quote from: TCWilliamson on February 01, 2014, 06:48:29 pmProbably less than you could pay someone who knows what they are doing to do it for

author: nctnico
author_rank: Super Contributor
timestamp: February 01, 2014, 07:50:57 pm
content: Quote from: TCWilliamson on February 01, 2014, 06:28:42 pmWhy the hell would you buy your own reflow oven? It takes lots of time to get the process right and each PCB more or less needs it's own temperature profile. There are so many companies out there who can assemble cheap. No, you don't have to go overseas for that. All you need is a UK phonebook.I second the others with their advice not to mess with tens of amps at mains voltages. You can do serious damage!

author: CM800
author_rank: Frequent Contributor
timestamp: February 01, 2014, 07:57:15 pm
content: Quote from: nctnico on February 01, 2014, 07:50:57 pmElectricity is much like a snake, treat it with great respect and take no chances.I do high power electronics in my spare time (Tesla coils, high power flyback transformers etc)I admit this is a step up, that is exactly why i came here and asked for informantion to be sure, learn any safety information and also look for any training course info.This equipment will not actually be used for PCBs, its a seperate product., i cannot disclose the exact product ( NDAs etc )

author: cybermaus
author_rank: Frequent Contributor
timestamp: February 01, 2014, 07:59:00 pm
content: It sounds more and more like you may not realize what you are getting into. You may be out of your league.Is it really a 74 Amp 61KW device you are looking into? That is a HUGE device. Either your friend has a real business (you mention NDA's?) and should not be shocked from needed infrastructure investments, or you guys need to scale down, a lot.Not sure about UK, but afaik in EU most domestic households have a single 40Amp main fuse. Houses with a appropriate 3-phase agreements have multiple 40Amp ones. Only bigger houses may have 60Amp ones. So you probably would not be able to power this will all the power allowed in all the sockets of all the rooms of your house, even if you shut down everything else.If this is already a business location, you probably still need to get the local utility to supply a new main fuse, which usually means getting a different class of agreement with them. With a 74Amps need you probably need to get 90 or 120 Amps (again, I am not sure about the UK) and that means35mm2wiring for short runs.All that extra copper is due to the so called skin effect, the current avoids the centre of the copper. For this reason, worst case depending on how far the closest one is, the utility company may decide (as mentioned above) to dig a new HV line to your premises.So really: if your plans include a 74Amp 480V 3-phase device, you need professional assistance, and assume the infrastructure cost alone will be way more then your UKP 5000 device + 2000 shipping. I know of someone who recently got a new 90Amp trunk for his new business location. I seem to recall him telling me his cost was toward Euro 60000. But I admit, they had to dig the new HV line almost 500 meters for him, and it did include his own private HV transformer (which he paid, but is not allowed to open or touch in any way) Even if you got all the certifications yourself, you would need to get the utility to supply that part. But at least you would understand why.

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: February 01, 2014, 08:02:23 pm
content: For that amount of heat, wouldn't gas heating be a better option?

author: CM800
author_rank: Frequent Contributor
timestamp: February 01, 2014, 08:11:27 pm
content: Quote from: cybermaus on February 01, 2014, 07:59:00 pmYou are wrong in this case, the actual item i have found is english now, most of the units around here have 3 phase 200A avalible.the device in question has a START UP CURRENT of 74A and runs from 415V 3-phase, standard UK power.all that needs doing for this machine is a cable from the fuse box, to the machine itself.The current of such a machine:I = W/(sqrt(3)*phase-phase voltage)soI = 28000/(sqrt(3)*415)I = 39AI would therefore use 8mm2 cabling for 3phase, i could buy such cable from a local distributer i know.this does not seem to bad, it is as much danger as wiring 3 showers, ofcourse, i shall go on a training course still for the paperwork for legal reasons.for.Quote from: mikeselectricstuff on February 01, 2014, 08:02:23 pmAfraid not, the item has to be gradually heated up through 10 sections at different places, the items also have to be -very- clean due to chemicals used in the process and what the items are

author: SeanB
author_rank: Super Contributor
timestamp: February 01, 2014, 08:24:07 pm
content: I personally would go for a 16mm 4+E trailing cable to the machine if it is movable, or a 4+E 16mm armoured cable to the wall mounted disconnect, and that in turn fed via the same cable from the distribution board with a 80A 3 phase breaker protecting the cabling. I would recommend a 100A or higher rated disconnector as well. In any case you are dealing with a very low impedance power source, so you will have to look at the short circuit ratings of the breakers and get them and the disconnector at a rating greater than the calculated level. Domestic and low power breakers will not work here, what you will need is both big, steel clad in a thick housing and heavy weight wise and price wise. most comes as a kit of parts and has a need for a big hydraulic crimping machine to attach the lugs to the cable. Probably best to rent the crimping unit instead of buying it.

author: CM800
author_rank: Frequent Contributor
timestamp: February 01, 2014, 08:33:40 pm
content: Quote from: SeanB on February 01, 2014, 08:24:07 pmThe local machine shop i worked at for 2 weeks at work experiance had 12 CNC machines, each of them had breakers like this:and had much higher ratings then this machine.Also, this machine, all the real chances of flash-over or 'explosions' would happen inside the machine, where the contactors for the heaters are.I can find a disconnector as you described not too hard, probibly on ebay or the same distrubuter i get the other stuff near us.EDIT:somthing like this then or is it overkill?Quote

author: cybermaus
author_rank: Frequent Contributor
timestamp: February 01, 2014, 08:40:34 pm
content: Quote from: TCWilliamson on February 01, 2014, 08:11:27 pmWell, that is why I asked 3 times if you were sure it was a 74Amp device. With all the post above, you never considered to add that info. Or even mentioned the 28KW you suddenly drop in that formula. So its a 28KW device?Still big. 39Amps you say? I come to 35Amps, but OK. That officially still needs 10mm2 that I remember, but 8mm2 is not an option that I know of here in NL, and rules and standardized materials may indeed differ in UK.However, you say 200Amps is "standard unit" in UK? I doubt that. Very much. Even if I do not know the rules in UK. For an entire apartment complex maybe, but not for any individual apartment or house.

author: CM800
author_rank: Frequent Contributor
timestamp: February 01, 2014, 08:45:14 pm
content: Quote from: cybermaus on February 01, 2014, 08:40:34 pmSorry, i hadn't noticed your question to that.A house fusebox is (at least our house is) single phase 100A input fuse, we can safely draw up to 80AThe fusebox in the industrial units we plan to rent are 3 phase 200A, that is what i was sayingIt appears the picture i posted did not come up, here are the stats:

author: Monkeh
author_rank: Super Contributor
timestamp: February 01, 2014, 08:54:43 pm
content: Quote from: cybermaus on February 01, 2014, 07:59:00 pmSorry, what? 35mm² for ~100A? Skin effect on a conductor of that size? This is 50Hz we're talking about.. I get a 100A supply through 16mm², and skin depth is10mmat 50Hz for copper. This means you don't give a crap about skin effect until over 50mm²!Quote from: cybermaus on February 01, 2014, 08:40:34 pmNo, he said most of the units (unit = industrial unit, an invididual section of a large industrial building on an estate) have a 3-ph 200A supply as standard. Which is not uncommon for mid-size units.To the OP: Please hire an electrician for this work. If you're not absolutely sure what you're doing, you should not be performing this work for a business, especially in what is usually rented rather than owned property.

author: bookaboo
author_rank: Frequent Contributor
timestamp: February 01, 2014, 08:55:20 pm
content: Honestly, get an approved industrial electrical firm in. This sort of stuff is their bread and butter.Any £ you save will barely cover your time and hassle (even if it all goes smoothly). All that time checking specs and regulations... they will know that off the cuff.Also there's liability issues galore, even if you do manage to cover all the regs correctly you might still get hassle if anything goes wrong.

author: CM800
author_rank: Frequent Contributor
timestamp: February 01, 2014, 09:00:02 pm
content: Quote from: bookaboo on February 01, 2014, 08:55:20 pmI understand what you are sayingbut I would rather learn how to do it myself, then I am qualified and can install any other equipment we use, and even do electrical jobs for other companys and housing ( father owns flats )It is also interesting, my career will be in power electronics too, its also my hobby, therefore, i would be safer to know 'what im doing' safely.What i could do, potentually, is wire it myself and get a 'qualified' electrican to check it all though and give me the paperwork, things like that are legal, also would save me an assload or two.

author: Fsck
author_rank: Super Contributor
timestamp: February 01, 2014, 09:05:52 pm
content: Quote from: bookaboo on February 01, 2014, 08:55:20 pmnot a "might". they'll almost certainly pin it all on you as being unqualified.

author: IanB
author_rank: Super Contributor
timestamp: February 01, 2014, 09:07:11 pm
content: Quote from: TCWilliamson on February 01, 2014, 09:00:02 pmIs this for you, or "a friend"? I'm confused now.

author: Monkeh
author_rank: Super Contributor
timestamp: February 01, 2014, 09:07:31 pm
content: Quote from: TCWilliamson on February 01, 2014, 09:00:02 pmhttp://www.cityandguilds.com/courses-and-qualifications/building-services-industry/electrical-installation/2391-electrical-installationshttp://www.cityandguilds.com/courses-and-qualifications/building-services-industry/electrical-installation/2382-requirements-for-electrical-installationshttp://www.cityandguilds.com/courses-and-qualifications/building-services-industry/electrical-installation/2396-design-erection-and-verificationetc etc, I don't know the courses in depth. There's some years of learning, not including practical experience, before you should even consider deploying large, 3-ph equipment in an industrial setting.

author: CM800
author_rank: Frequent Contributor
timestamp: February 01, 2014, 09:11:08 pm
content: Quote from: Fsck on February 01, 2014, 09:05:52 pmIf i remember correctly, i said that i would do this after doing the course, or have a qualified electrician come in and check it, therfore, its on their head if anything goes wrong.Anyway, this i guess is sorted on what to do....On the other hand, there is another peice of equipment we need to modify, this one is only single phase 8A, so very little risk as its a 13A socket plug in, somthing i have done a lot of wiring with and know how to do safely.Would it be all good and happy legally if i brought a used pick and place machine and modified it heavily?What we are doing, is basicly, we cannot afford custom machines and automation, so we will be re-purpousing PCB production equipment for the product.Quote from: Monkeh on February 01, 2014, 09:07:31 pmYeh... screw that... il just do it all and have a qualified guy come in and check it over, much safer and easier, and completely legal and all is good.Quote from: IanB on February 01, 2014, 09:07:11 pmSorry, its hard to explain, you might as well see it as both, this company is a startup and we don't wish for competitors to catch on to what we are doing hence why i can't reveal much.

author: Monkeh
author_rank: Super Contributor
timestamp: February 01, 2014, 09:15:58 pm
content: You'll be entirely liable for any disasters caused by a device you've modified. Insurance is not likely to help you.

author: cybermaus
author_rank: Frequent Contributor
timestamp: February 01, 2014, 09:18:07 pm
content: Quote from: Monkeh on February 01, 2014, 08:54:43 pmHuh. I went back and looked in my old books. You are correct, sorry. Should not have done it from memory, its been too long. Books seem to indicate 3x16mm2 is allowed up to 150 meter runs for 100A. (I did do installation work, really, 20 years ago though). And they did tell me all those years ago it was due to skin effect that the cables got above linear thicker at higher currents, so I am not so sure if your 20mm is correct, but my references are silent about that. Just lists of required by code values.Still, base advise to get a local installation bureau seems to hold, is in fact even strengthened by my mistake. But that point seems to be repeated ad nauseam at the moment.

author: CM800
author_rank: Frequent Contributor
timestamp: February 01, 2014, 09:20:37 pm
content: Quote from: Monkeh on February 01, 2014, 09:15:58 pmThat is only reasonable, much better then "If you modify the equipment without paying 100,000 to the gov you will be put in jail and fined heavily, if the machine is safe or not."

author: IanB
author_rank: Super Contributor
timestamp: February 01, 2014, 09:22:56 pm
content: Quote from: cybermaus on February 01, 2014, 09:18:07 pmIt's about the length of the cable run. The minimum thickness is set by allowable temperature rise in the cable. However, longer runs will incur a larger voltage drop, so you may need a cable that is thicker than the minimum for long runs to maintain an acceptable voltage to the device being powered.

author: Monkeh
author_rank: Super Contributor
timestamp: February 01, 2014, 09:25:38 pm
content: Quote from: cybermaus on February 01, 2014, 09:18:07 pmVolt drop is a little extreme at that range, and you must take into consideration the balance of loads with 3-ph..

author: Frost
author_rank: Regular Contributor
timestamp: February 01, 2014, 09:27:36 pm
content: Quote from: TCWilliamson on February 01, 2014, 08:33:40 pmThis is not a circuit breaker.Like you can see on the pictogram at the right corner, it's only a switch.

author: Monkeh
author_rank: Super Contributor
timestamp: February 01, 2014, 09:30:04 pm
content: Quote from: Frost on February 01, 2014, 09:27:36 pmThe red lever and lack of a fault current rating or trip curve are also dead giveaways.This is a 100A 3P MCB:Note the width..

author: CM800
author_rank: Frequent Contributor
timestamp: February 01, 2014, 09:41:15 pm
content: Quote from: Frost on February 01, 2014, 09:27:36 pmAnd your the only one to notice that!I know it wasn't, but it looks exactly like the circuit breakers they used there.

author: sacherjj
author_rank: Frequent Contributor
timestamp: February 01, 2014, 10:00:34 pm
content: Quote from: TCWilliamson on February 01, 2014, 08:33:40 pmThat is just a switch, not a breaker.Edit: Whoops, read to the end before replying. Looks like I'm a couple minutes late to the party.

author: CM800
author_rank: Frequent Contributor
timestamp: February 01, 2014, 11:03:36 pm
content: Well i guess we have discussed all that need be discussed, Thanks for the information guys!

author: SeanB
author_rank: Super Contributor
timestamp: February 02, 2014, 06:05:26 am
content: Use the big fused disconnect, and put 100A fuses in it. Will be a little overkilll but that gives a very good overload margin, and the fuses are backup to the breakers in the main board, which can pop or weld together. Buy a set of spare fuses. Not likely you will ever use them,but they are expensive to buy when they pop at the most inconvenient time. At work the metro has a small 200kVA substation there that feeds us, the buildings next door and a link to the 1MVA sub upstream. The 200A fuses for 2 phases popped after 40 years of service. I measured the current through them one day ( metro guys were there to change the fuses and they had the clamp meters) at 220A on one phase. The fuse was quite happy with this load. I balanced our load a bit as well, as there was a 100A neutral current on a hot day. Dropped to 40A after some phase swapping on single phase airconditioners in some boards.

author: CM800
author_rank: Frequent Contributor
timestamp: February 02, 2014, 05:21:06 pm
content: Quote from: SeanB on February 02, 2014, 06:05:26 amAbsolutely, thanks for the infoCan someone lock this thread or can it be left to die now? i don't think anything need else be said?

author: SeanB
author_rank: Super Contributor
timestamp: February 02, 2014, 05:50:43 pm
content: You are the owner, so you can lock it.

author: CM800
author_rank: Frequent Contributor
timestamp: February 02, 2014, 05:59:26 pm
content: Quote from: SeanB on February 02, 2014, 05:50:43 pmWait, how XD

author: IanB
author_rank: Super Contributor
timestamp: February 02, 2014, 07:33:56 pm
content: No need to lock threads, just leave them alone to drop down the list.