Not to change the topic but in further discussing or understanding distribution
unit design problems and concepts, continuing the topic and further detail of the US/Euro wired
E-Stop from last week might be useful.
Doing US/Euro
power supplies is very difficult - where the industry is going but hard to engineer something that’s universal - not as easy as a switchable moving light
power supply or just changing the lamps in a
fixture. Many companies are working on such gear and soon will have UL listings on it, but most at least
power supplies have very difficult problems to overcome first. My big boss’s want’s such gear badly, and TBA more and more, all new gear we make these days as with this project have this “world tour” concept in mind with it. (Means I need to go to school for Euro wiring and code more than I have.) At the shop in buying and building the gear, we are working on this
vision, it’s not cheap or easy to get and there is major differences that require huge compromises or changes at this
point. Huge problems in getting it universal - at times in debate with what our
current power supply engineers specify of what we will get, I can state the
NEC until I’m blue in the
face in defense of some standard we use or need and the manufacturer of our next generation of AC
distro still says no, can’t do it... type stuff. Last I knew, we were getting something at this
point, it’s going to be difficult to make full use of.
Onto the
current E-Stop problem.
I was doing the
electric, the electronics department was doing the electronics and
relay specifying and constructing part of it. The person from that department who did the electronics agreed that he could have made his part of it Euro/US, but only - given more R&D pre-production time than less than a week. I could probably also have done some stuff differently.... This granted, already both of us had full schedules of stuff to work on for that production and many other shows, much less had set backs in design. Stuff like "I thought you were buying the Emergency Stop switches" type interdepartmental problems - on the last day which forced us to
send it off a day late by mail to catch up with the show. This and given all worked without huge problems, only one lost hour trying to figure out why the remote stops didn't work... something about something forgotten on them which challenged our
UPS pickup time. Hmm, remote kill switches that will work as a
system no matter how many are plugged in? Just takes some circuitry but an added component.
Anyway, the specified design concept was to have
circuit breakers that could handle both 120v and 230v
power systems. That was not a problem, most are rated for either 240 or 250v and don't care if a 120v or 230v world - it's about the amperage.
Power in was to be the US based L21-30 which is three
phase five
wire twist lock. No real problem to adapt to it for a Euro
plug. Output was to be the alternate/
safety config. of 208v
Socapex that has it's wiring/phasing set up in such a way that if you
plug a 120v output into it, it won't blow up what's plugged into it. Beyond that, there was to be two low
voltage remote kill switches that ran off 4-pin
XLR cable. This was the specification as planned by the production managers.
Problems came in the reality of the wiring and or my understanding of Euro wiring. It has always been my impression in the past that normal Euro wiring used 230v hot and a
neutral. This would tend to be a huge problem with this was wired for the dual 120v hot
leg 208v that's
fed by three
phase power and would not use the
neutral leg of
power other than for needs by the
circuit board and various indicator lights. Ain’t no neutrals in this 208v
Socapex plug, how are you going to
power it up for 230v six
circuit?
Unless I mis-understand Euro wiring for what is in the US, two
phase 208v gear, Euro stuff 230v in general would not see two hot legs ?416v, (which when put to him, the specifier of the gear also had to scratch his head and wander off in not knowing for sure - this after yelling about our lack of ability to do specifically as he asked.. Ok, I did exactly as he asked but I should have made it dual input anyway somehow as desired.) Euro gear such as a in this country two
phase ribbon lift, would in Europe at least I believe normally see one hot
leg at 230v single
phase and a
neutral thus be a single
phase item or would it? I scratch my head also on this - don’t know, didn’t research sufficiently given the one week turn around. Only way to get such
power supply - unless Euro is two hot legs/two
phase also, would be to totally re-wire, remove wires from breakers and put them into
neutral bus bars from a US based
system. That’s stuff I don’t fully know yet, nor had time to research in the (new technology) ribbon lifts this was to
power up if it’s in wiring for Euro needs, having a hot and
neutral or still two
phase power. This was a major/huge detail I could not design for thus did not.
This much less from the wiring standpoint I was doing, doing
power in indicator lights would be much more difficult. Short of circuitry to show what
phase was missing in going
phase to
phase indicator lights as opposed to one indicator light hot to
neutral per
phase. Were I to do
phase to
phase indicator lights, one would know there is a problem but not know which one had the problem easily. Otherwise in just indicator lights on the
power in side, were I to go
phase to
phase in doing 250v, I would either blow them up once they hit Europe or if I did 250v indicator lights in going hot to
neutral, have lights at half their
intensity in doing 120v which might not be bright enough.
No such thing as a over 250v indicator light that I’m aware of, so doing any form of indicator lights on the
power in much less
power out for two
phase six
circuit indication just became very difficult. Potentially I could do half bright 250v hot to
neutral indicator lights for the
power in, but there would be no way of doing a
phase to
phase two
phase individual
circuit indicator light short of doubling the 250v lamps now for each
phase of
power - 12 lamps tied to the
neutral instead of just going between the two phases of
power. (Could have solved the problem, was not easy or effective for this first attempt.)
Now anyway in wiring the thing, we were faced in six
circuit 208v output with the potential unknown problems of for Euro shows somehow removing the now second hot
wire legs tied into the three phases of
power and turning them into
neutral legs instead.
IN theory, one could leave the neutrals in the dual two
phase breakers - Code requires if switching off the
neutral, it’s absolutely switched off at the same time as the hot. It’s just not normally done that way but a dual pole
circuit breaker would do so. While not good practice, one could in theory use a dual pole
breaker with the
neutral running
thru it for such an application. (Wonder if it would survive a PATT test this theory by Euro wiring standards?) Now we would just would need some form of say
three way multi-pole
switch that would
switch each second
leg phase of
power between 120v and
neutral. Not aware of such a thing existing but I’m sure it requires circuitry and some form of
relay switch -
three way 30A three pole
relay switch if such a thing exists to
switch the second poles of a 208v
system between 208v and the
neutral leg of a 230v
system. Probably would also require some form of
safety circuitry to safely do this.
So now in doing a three pole
relay switch that's controlled by the circuitry (in this case at 120v), we either have some form of six pole
relay switch that treats hot and potentially hot or
neutral depending upon the country it's used in differently or have to pre-relay the switchable
power imput three pole
relay switch with some form of
neutral/hot switching threeway
relay switch before the
E-Stop controlled
relay switch. This six pole and or
three-way relay switch than would also have to be circuited in with switchable
power supplies for the rest of the circuitry, otherwise one might hit one switchable or auto-detect
power supply
switch or
transformer but not a second one. The circuitry in detecting a need to kill the
system at 120v or 230v is a seperate componet than that of the component that does the actual switching. Easy enough to splice or
wire but more components to add and troubleshoot.
Them’s major problems in my understanding beyond the concept that a L6-15 two
phase plug - normally we would use to distribute a 208v
Socapex plug to six individual fixtures is rated for 250v. If it’s true that this
Socapex plug (if even rated for six circuits of ?416v) is now doing 12 circuits of 230v, the plugs we by design will have been distributing the dual
phase 230v load with will at over 400v have been not rated for the
voltage. This much less nor would the 12/3 SJOOW cable such a fan-out of
power the cables making up the fan out will have been wired with been rated for. 12/3 SJOOW cable is only rated for 300v. Electrically, even if this thing were able to do both US/Euro in going to a
Socapex output, nothing existing as normally used in the US or Europe distributes
Socapex to 12 hot
wire to over 300v six
circuit output. No such thing. Intended was to use our 208v wired six
circuit fan-outs.. They are rated for 250v at the
plug and 300v on the cable. That means we would either have to re-wire the
power supply so it’s using neutrals, or figure out some other form of no longer universal way to distribute what
power the rack could supply. Not easy to do universal.
Electronically, I assume that 60Hz verses 50Hz will not have been a problem for the circuitry - this and what
power it’s
fed could be switched
thru a
transformer. This granted in-line
safety fuses and other circuitry to ensure you don’t blow up a
circuit board and other relays
etc. All will have required a larger rack mount space also than the 6" deep two rack space panel I attempted to use and was challenged to fit all into. This was one of those cases of - yea, I know CU requirements and I added venting to the thing, but didn’t have time to do a larger than off the shelf rack mount housing. Looks good and is safe but the Cubic inches of cooling space within is negotiable given ventilation provided to supplement it.
A month will have been needed to design such a thing for dual Euro/US
voltage needs. This in addition to inter department design/production meetings (as if production meetings for a show) on it that’s un-heard of other than for huge projects.
Here is what I at least wired in doing it for a three
phase to six
circuit two
phase Emergency Stop
system in the 120v/208v world:
Power in, L12-30P flange mount 120/208v
Wye 30 Amp
plug. #10 MTW
wire to a Square D series QOU 30Amp 3-Pole
circuit breaker.
Neutral was sent to an isolated four hole
neutral bus, and
ground to a bus / grounding strip of the same amount of holes by the same
gauge and type of
wire above, but in this case mounted directly to the panel. Off the main
breaker was 120v indicator lights wired off each of the load side of the three poles and in
return combined and tied to a
neutral wire going to the
neutral bus bar. Also, on the X and Y phases,
power to a
circuit board and to the
power relay. Both also had a
wire leading to the isolated
neutral bus - about the extent I did beyond mounting components in wiring the circuitry. I do relays as needed, in this case, circuitry was another department and I worried about my own.
Circuit board
fed the three
phase power relay which the main
circuit breaker in the same
wire was feeding.
Circuit board than took it’s instructions from the various by now three (one rack mounted) emergency stop switches that were store bought. Two remote kill switches were remote and
fed by way of four pin
scroller cable but this
switch needed to have the option of not using any or all remote kill switches, and or if there were a problem in wiring, compensate for it in any working irrespective of what another kill
switch was thinking - other than if locked into the off position. 4-pin
XLR off the rear of the
panel mount power supply
fed the remote kill switches - this needed to detect if they were plugged in or not in still working. Also out of
safety and idiot proofing, it needed to be safe incase someone plugged in a either 4-pin
headset system to this emergency stop
system, or anything from a
scroller to a
LED based Color Blast
fixture to it. In other words, 4-pin
XLR is fairly common in use thus we had to design around it to idiot proof the gear. Used pins 2 & 4 for the remote kill switches, and 1&3 for bridging between them to tell the detection / shorting
circuit if something was plugged in or not. (There was some design to this, just not enough time to make it universal.) Given it was only a 5v
relay signal, it made it easy on amongst four types of
scroller/Color Blast 4-pin
XLR cable in
stock, we were able to use the never used “Color
Fader” type cable which doesn’t have the 14ga wires in it, the cable that’s rarely used and obsolete. That at least is a good thing - just using the cable for a
relay signal and not needing the more used cable.
So the
power and control is now at a three
phase 30Amp
relay switch. (The
power relay talks to the
circuit board somehow that was the electronics department based.) Anyway, #10 MTW
wire from there to a three pole four output Marathon
block, four circuits three pole of #12 MTW
wire out of it going to six two pole 20A magnetic
circuit breakers. These are phased and wired as per the “plan B” in the industry alternate method of wiring 208V
Socapex so it don’t blow up if you
plug a 120v application into it.
Circuit breakers go to the
Socapex outlet along with six
ground wires dual wired into the three terminals of the
ground bus. Each output for the six
circuit two
phase circuit breaker also had a 250v indicator light wired between output on the
breaker for the
breaker so as to indicate individual
power and overall = “it’s been killed
power.” I indicated
power in (after the main
breaker) and
power out (after the output breakers.)
Socapex plug leads to a fan-out or as it were
Socapex male
Veam brand VSC series KK clamp type six
circuit 12/3 SJOOW output to L6-15R
adaptor. (Industry standard these days is more the L6-20
system but it would cost too much to convert at this
point.) Anyway, it’s a
Socapex male to six individual cables of 208v
power adaptor which than feeds each individual
power supply to the hoists. This part of the
system, even if it were a switchable
power supply would be problem #2 to why it cannot be easily done as per requested design. Nope, no way to do it.
Not a lot of time or room to do other than what we did. Nice clean and working 120v/208v
system package. A few errors on my part in labeling the rack than adding stuff, but overall = very easy to understand and safe.
Doing it 120/208v and 230v/?416v? That would require lots more work and time. Can’t be done easily.
Lots of details left out such as crimped ferrules,
insulation and isolation of the
circuit board
etc. Wiring and making
power supplies is complex. Add to that the mandate of making it dual
voltage and given less than a week with lots of other stuff to be working on... nope... Be easier to make a seperate 230v
power supply before the tour gets to Europe than to put everythign else asside within the time limits.
