"My Kingdom for a Horse!" What have you been stuck without?

"My Kingdom for a horse!" - improvising a 24V tester lamp/light

I'm on a job 2 states away from home to configure recent additions to a data acquistion system. The panel is 15 years old with a mishmash of changes-over-time; a ton of 'abandoned' cables and wires - a real rat's nest.

While troubleshooting a missing signal I was digging through a pile of cables to find where #618 goes, and suddenly the 24Vdc power supply dies taking out of service a set of process-critical sensors. The 24V glass fuse had opened. I found a can of fuses in the bottom of the panel, and put another in the fuse holder which immediately burned out, so there's a short to ground somewhere. Wiggling the wires must have done something bad. Grumble, grumble; other people's ugly, stupid wiring, grumble, grumble.

First things first, I had to get the critical instruments back up and running. The criticals were powered by a (+)/(-) pair wires running from the terminal blocks. I had a spare 24Vdc supply in the car with line cord on it (duplex in the panel), so I grabbed it and connected its output to the critical sensor power line. That powered them up, but now I had to find the short. I had come prepared to do paper work and minor configuration with a PC, not circuit troubleshooting. I wasn't supposed to install or wire anything. But now I needed a 24V lamp/light that I could put across the fuse to act as a load and be a visible 'short' indicator to sort out what was going on.

I called their maintenance guy and he showed up with a 90-300Vac neon tester and a 12V tester, the kind for autos with a sharp probe that pierces wire insulation. The first won't see dc, the second would blow out its 12V bulb in 24V circuit. Although the plant had 2 or 3 PLCs and a couple dozen 24V powered instruments, the maintenance guy did not have a 24V panel bulb or 24V anything.

King Richard III's line is running through my head - "A bulb, a bulb. My Kingdom for a 24V bulb" ! !

I quizzed the locals about where to buy stuff. This town an hour's drive from a Lowes' building supply, 2 hour's drive from a Graingers/electrical supply house. The Radio Shack had closed about 6 months ago. The Hardware store had closed at 5PM. Finally, it dawned on my that I could use a couple automotive bulbs. There was an AutoZone close by so I drove over and lucked out to find a pair of 194 bulbs (GM side marker and instrument panel bulbs through the 1990's) and their sockets with flying leads



I treated myself and even bought a package alligator clip jumper leads.

I wire nutted the two bulbs in series to get my 24V indicating load and alligator clipped each lead onto the fuse holder contacts. Bulbs lit up and I started wiggling wires until the light flashed a couple times. I dug around the cluster of wires that I was jiggling and found an 'abandoned' pair of wires with a 250 ohm resistor soldered across them. One side was 'hot' 24V. Apparently this panel had had 2 wire, loop powered transmitters and had taken them out of service, but hadn't disconnected the wiring from the power supply. I poked around and found a couple more exposed wire 'hot' ends (soldered to resistors) in the pile of cables. I pulled the wiring and disconnected it at the power supply.

The test bulb was off and the replacement fuse didn't blow so I could get back to the config job.

Whew. Lesson learned. I put a 24V tester light in the vehicle tool box.

Sort of in the same vein...

I went to a machine startup in Mexico once (well, twice, but that's another story). I would check a toolbox with just the basics when I flew, and somehow the apes in baggage handling managed to break off the carry handle which made getting around with it pretty difficult.

On site, I poked around until I found a piece of 1/2" EMT about 5" long, and a couple of feet of cast-off rope. Voila'! Instant replacement handle.

Used it like that for quite a while, too, until I finally replaced the toolbox.

internet access - when you need to update a gsd you'll pay anything to plug your own laptop in.....most other things can be bodged

Once flew in to Belarussia, with a connection that is infamously known for always missing getting the luggage on the plane. So I wisely packed everything critical in my carry-on bag, laptop, power supply and cable, profibus adapter, backup of all software, printed copy of the documentation, etc.
Sure enough, on arrival there was no luggage with the plane. "good thing I packed everything I need in my carry-on" I thought to myself.

Onsite, I start to hook up my laptop to the PLC. Profibus adapter (PCMCIA) is there, but where is the adapter cable ... ?! Oh nooooo......., I packed it in the luggage.
So I was looking at having to extend my stay for 2-3 days just because of this *&%#* cable. And the cable was special with a little proprietary plastic connector to go into the PCMCIA card. No way I can make one myself, or get one locally.

Well, when you are naked you start to knit. So I looked around, and found a PC with some data logging software hooked up to the PLC. Long story short, I managed to get my programming software and licenses on the PC, and could get the job done without having to extend my visit.
My luggage came on the last day when I was getting ready to leave.

JesperMP said:

Once flew in to Belarussia, with a connection that is infamously known for always missing getting the luggage on the plane. So I wisely packed everything critical in my carry-on bag, laptop, power supply and cable, profibus adapter, backup of all software, printed copy of the documentation, etc.
Sure enough, on arrival there was no luggage with the plane. "good thing I packed everything I need in my carry-on" I thought to myself.

Onsite, I start to hook up my laptop to the PLC. Profibus adapter (PCMCIA) is there, but where is the adapter cable ... ?! Oh nooooo......., I packed it in the luggage.
So I was looking at having to extend my stay for 2-3 days just because of this *&%#* cable. And the cable was special with a little proprietary plastic connector to go into the PCMCIA card. No way I can make one myself, or get one locally.

Well, when you are naked you start to knit. So I looked around, and found a PC with some data logging software hooked up to the PLC. Long story short, I managed to get my programming software and licenses on the PC, and could get the job done without having to extend my visit.
My luggage came on the last day when I was getting ready to leave.

Click to expand...

One of the benefits of VMWare images

This was 15 years ago (hence profibus and no ethernet).
Way before it became normal to run the software in a VM on a normal laptop.

During a commissioning many years ago. The machine is in limited production. The commissioning crew is still debugging. We managed to let the smoke out of a 24 VDC power supply on the weekend. No replacement in spares.
The plant had a lot of battery powered movers (12 volt) so we parked two of them next to the control cabinet and wired the batteries in series so we could get running again. Then we went to an auto parts store and bought two car batteries and a charger. Alternated charging the two batteries. It kept us running until we could replace the power supply.

Wasn't me personally but I was the one giving phone support to one of our technicians. He was in Venezuela, and for anyone who doesn't know about Venezuela to buy a nut or a bolt in Venezuela is complicated never mind anything more technically advanced than that.

Our technician went to install a new machine. Since it was a new machine he only took with him his laptop, an ethernet cable and a USB cable, we had stopped using Serial about 2.5years earlier.

When he arrived he discovered that it was indeed a new machine, however the machine had been bought 4 years earlier and had never been taken out off the pallet, he looks at the PLC, a Micrologix 1500!!!

He asks the guys at the plant if they had a serial cable, No , if they had any DB9 connectors, No , if there was somewhere near by that he could buy some, No ! So it looked like he was screwed but then he remembered the cable connecting the micrologix 1500 to the PanelView Plus. Well the pinout wasnt the same but he unsoldered the cable and resoldered it to the configuration to communicate!

That was great and he got it working, but then everytime he needed to test the panelview he had to do the reverse! During the week he probably unsoldered and resoldered that cable about 5-6times a day! Everytime we'd be testing and go, "Right now need to test the PanelView", he'd reply "I´ll call you back in 10minutes when I'm finished soldering".

When he got back to the office, he spent the next monday making up all the serial cables you could think of, PLC to PanelView, PC to PLC, PC to Ultra 3000, PLC to Ultra 3000 etc etc etc, He now carries them around with him even when he knows that there is no serial ports in the whole facility where he is going

Steve Bailey said:

The plant had a lot of battery powered movers (12 volt) so we parked two of them next to the control cabinet and wired the batteries in series so we could get running again.

Click to expand...

Good call.

That's what the operators at the Fukushima nuclear power plant did to get DC power for the instrumentation after the earthquake scrammed the reactor and the Tsunami took out their back-up diesel generators or power distribution panels.

They scavenged car batteries from the parking lot and wired them up for DC power.

http://spectrum.ieee.org/energy/nuclear/24-hours-at-fukushima

Usireland said:

Wasn't me personally but I was the one giving phone support to one of our technicians. He was in Venezuela, and for anyone who doesn't know about Venezuela to buy a nut or a bolt in Venezuela is complicated never mind anything more technically advanced than that.

Our technician went to install a new machine. Since it was a new machine he only took with him his laptop, an ethernet cable and a USB cable, we had stopped using Serial about 2.5years earlier.

When he arrived he discovered that it was indeed a new machine, however the machine had been bought 4 years earlier and had never been taken out off the pallet, he looks at the PLC, a Micrologix 1500!!!

He asks the guys at the plant if they had a serial cable, No , if they had any DB9 connectors, No , if there was somewhere near by that he could buy some, No ! So it looked like he was screwed but then he remembered the cable connecting the micrologix 1500 to the PanelView Plus. Well the pinout wasnt the same but he unsoldered the cable and resoldered it to the configuration to communicate!

That was great and he got it working, but then everytime he needed to test the panelview he had to do the reverse! During the week he probably unsoldered and resoldered that cable about 5-6times a day! Everytime we'd be testing and go, "Right now need to test the PanelView", he'd reply "I´ll call you back in 10minutes when I'm finished soldering".

When he got back to the office, he spent the next monday making up all the serial cables you could think of, PLC to PanelView, PC to PLC, PC to Ultra 3000, PLC to Ultra 3000 etc etc etc, He now carries them around with him even when he knows that there is no serial ports in the whole facility where he is going

Click to expand...

I have one just like that for 5/03 and panelviews - double headed for the PLC/Panelview connection - I don't suppose it will ever get used again - I must say that as much as I moan about installing Simatic software, I don't moan about the ease of which drives can be configed using the PLC as an profinet-->profibus PLC bridge.
I can't say I miss carrying around a million different bricks and cards and cables just to be sure to be sure

Flew to Valdez Alaska for startup on a SCADA system for the Alyeska Pipeline plant vapor recovery and power generation system. Sq. D Symax PLCs, the system shipped without the special network terminating resistor and the way those were arranged, you couldn't rig up a substitute without having access to a good supply of electronic components, but there was not even a Radio Shack in that town. Had to have it flown into Anchirage, but the part would arrive after the last cargo flight to Valdez. So I had to take "Wilbur's Airlines" a 6 seater Cessna, to Anchorage to pick it up. On the way, the pilot took a dive bomb run INTO the crack of a glacier for the other passenger. I tossed my cookies. After I got back, the pipeline people were shocked that I got back so soon because it had been too late for the regular commercial flights. When I told them I had taken Wilbur's, they when white in the face. Apparently Wilbur used to have 2 planes, but his brother cradled one into a glacier! Alyeska forbade employees from using Wilbur's...

Side note, when I was there was the week in which the Exxon Valdez was taking on the oil it ultimately spilled in Prince Wlliam Sound. I had taken a pic of it at the terminal, just because I thought it was odd that the tanker was named for the town. I sold the pic to a news agency for $1k, but they insisted on having the negative and all rights to it.

The posts about using batteries reminded of what my co-worker did when the battery charger on our substation protection system failed in -30 celsius weather. Turns out our maintenance cart is the same voltage - had a welding truck running to power the golf cart charger and jumper cables to the substation. Got it running before any freezing damage to the plant and kept us running until parts arrived.

I may told this once before.. but my memory is fading...

Got waken up early (I was working swing) and someone on the line asked if I have a passport... uh..ya.. I think I got one.

So some CNC type machine on-loan at a machine shop up in Canada is broke. It happens to make a critical part for our assembly plant. It's not PLC controlled but rather a custom built box with PC and bunch of circuit board. I'm not versed in electronic repair but they thought it would be wise to get someone with the title of "engineer" up there too. So we went..

The tech I went with diagnosed a blown capacitor or something and the only place to get this is from the original machine shop some where in the mid-west USA. OH yes, we need this NOW. Guess what, the other company big shot there took out his credit card out and ordered up a private plane to fly it over. and.. it blow again as soon as one of the welding machine near by got powered up. Turns out to be a bad ground in the plant. The big shot refused to order up another lear-jet for a capacitor so we called around and found some sale guy for our brand near by to take an all expense trip to Canada with the condition that he picks up the capacitor and bring it over. I guess the $2000 last minute ticket was way cheaper.

There are other stories too; this is why I rarely advocate for one-off-solution and nickle-and-dime on components. How much is your downtime worth?

Got waken up early (I was working swing) and someone on the line asked if I have a passport... uh..ya.. I think I got one.

Click to expand...

Never, I repeat never answer that question with a YES until you know what you are getting into!!

I did and ended up way up north in Canada on a Friday night. I also got the "Private Jet" treatment.

Usireland said:

Wasn't me personally but I was the one giving phone support to one of our technicians. He was in Venezuela, and for anyone who doesn't know about Venezuela to buy a nut or a bolt in Venezuela is complicated never mind anything more technically advanced than that.

Our technician went to install a new machine. Since it was a new machine he only took with him his laptop, an ethernet cable and a USB cable, we had stopped using Serial about 2.5years earlier.

When he arrived he discovered that it was indeed a new machine, however the machine had been bought 4 years earlier and had never been taken out off the pallet, he looks at the PLC, a Micrologix 1500!!!

He asks the guys at the plant if they had a serial cable, No , if they had any DB9 connectors, No , if there was somewhere near by that he could buy some, No ! So it looked like he was screwed but then he remembered the cable connecting the micrologix 1500 to the PanelView Plus. Well the pinout wasnt the same but he unsoldered the cable and resoldered it to the configuration to communicate!

That was great and he got it working, but then everytime he needed to test the panelview he had to do the reverse! During the week he probably unsoldered and resoldered that cable about 5-6times a day! Everytime we'd be testing and go, "Right now need to test the PanelView", he'd reply "I´ll call you back in 10minutes when I'm finished soldering".

When he got back to the office, he spent the next monday making up all the serial cables you could think of, PLC to PanelView, PC to PLC, PC to Ultra 3000, PLC to Ultra 3000 etc etc etc, He now carries them around with him even when he knows that there is no serial ports in the whole facility where he is going

Click to expand...

LoL I did the same thing. I ordered all the parts I could think of, and every time we get some new weird connector it is right to mouser I go. I prefer making my own cables to ordering pre-bought when possible.

My story isn't too bad. We had a Panelview go down one time and I dug around in old boxes for about an hour. I had no idea if it worked. The one I had to replace was 110V and this one was 24V. The first thing I noticed was that there was no connector for the power pins. I dug around in boxes of electronics for another hour or so until I ran across one that *could* work.

I used some side cutters to snip off the extra pins and filed that thing down until it would fit. Then I had to spend a while longer digging around for a 24V power supply. I found some old Omron cabinets that were about 10 years old and asked if they were still in use. This was now an allen-bradley plant so they weren't being used. I snagged a power supply out of one of those. I wired it up, tested it, got the right version of firmware on it and loaded the program. To my surprise it actually worked. Still being used lol.