Hello, I have an old 1979 Grove RT528. I currently have issues with none of the hydraulics functions working (swing, boom up/down, outriggers, winch, etc.). Background: All of the crane functions were recently working. The main hoist cable made contact with a power line momentarily (big mistake I know) and some sparks flew. The crane swung, touched the power line and immediately swung off (was in contact with he line for maybe a second, sparked cable touched and sparked when it swung off). The operator then swung the crane safely away from the power line and powered the machine down. After the situation was assessed and it was confirmed that there was no damage to the power line and that the area was secure and safe to work in again, the operator flashed the crane back up. All of the hydraulic functions still worked at this time. After about 3 minutes of using the crane, the operator was booming down and cabling up, at this point all hydraulic functions stopped working. The block is still a long ways away from making contact with the shiv which makes me certain that it has nothing to do with the A2B being tripped. I also have made contact with the A2B manufacturer and they said that it would not shut down all hydraulic functions if it was tripped, just the ones that can make the situation worse. I also checked to see if the transmission was working to ensure that it was not the fibre gear, and all gears in forward and reverse worked. I am not mechanically inclined and am looking for any input people may have on where to start trouble shooting so I can point my mechanic in the right direction. I am not sure if making contact with the power line has anything to do with the hydraulics not working as they did for a while after, or if it is just a coinencedensce. I am also curious if anyone has any input on how much damage could have been caused to the cable, winch, etc. from momentarily contacting a power line. Thank you for your help. -Nick
Sounds like your hydraulic pump kicked out of gear. Check that first if you haven't.
Any fluid leaks after the contact? maybe its low on fluid? Any circulation in the tank with the machine running?
I'm with knepptune, I bet in crawling around and inspecting, someone bumped the engage lever and kicked it out of gear. One of my operators contacted a power line 5 years ago. We scrapped the cable, inspected the whole crane. I was fortunate in mine the electric followed the cable, down through the cable rigging, and the load, to the ground. The most likely points of damage are if it welded/ arced any of the following items (most likely to least likely): turntable bearing , jack cylinder, boom cylinder, telescope cylinder, winch, hydraulic/electrical swivel. If the electricity comes back down the crane, most likely it will create small weld divots on the turntable bearing/ races/ balls. It may swing, but those spots will grind out grooves and ruin the bearing, I know of a link belt lattice truck that was scrapped for that. If it got the cylinders, you'll see the black spots where it arced across, inspect them all. The electricity follows the path of least resistance, and its hard to know where that might be, and what it may have damaged, you may not find all the damage right away.
You guys were right! The hydraulic pump was kicked out of gear. I have no idea how that happened however as the operator was sitting in the chair when all of the functions stopped working. It must have barely been engaged and shook loose. Thanks for the help, it took my mechanic 5 minutes to fix as that is the first place he looked. Now just to decide what to do with the crane because of the power line incident. I am guessing the current traveled through the crane because the ball was at least 15' off the ground with no load on it. The crane was up on all four stabilizers with wooden outrigger pads underneath. Does that help at all from insulating the machine from it being grounded? I am not to familiar with electrical currents and how they travel. There is also two winches on the machine, one of them does not have a ball on it and the cable is rolled up at the winch. Would that mean one would have to replace both cables? I find it hard to believe a momentary contact with a line like that would compromise the strength of the cables. NickR
There's a detent ball that should keep that pump engaged. It's not terribly uncommon for the forks on the shifter to be worn. It allows that gear to pop out. Kinda like a transmission that's not all the way in gear. It'll hold untill your working it and then kick out. It'll happen again. I'll try to post a breakdown so you see what I'm talking about. It is possible that someone bumped it but I bet that's not it. On the contact with power lines. I don't know. I'd probably cough up the money and have a 3rd party inspection done. For some reason I have trouble seeing it damaging anything structural without frying all the electrical. Crane op covered most of it. And I agree with him on replacing the cable. For $3-4 a ft you can have brand new cable. I'd spend the money on that.
The cable needs replaced, not the cable spooled on the other drum. If you have trouble imagining electricity traveling through the crane, imagine the power line as your lead on a stick welder. Imagine earth as your ground clamp. Strike a arc. When your welder leaves those little divots where the ground clamp is, that's what the power line is doing, to everywhere the electricity had to travel. It only takes a split second. Lightning doesn't last long either but you don't want it hitting you. The steel cable becomes brittle from the heat. Somewhere it jumped from cable to boom (another arc point, probably at the sheave, but could have gone clear to winch). Somewhere it jumped from boom to upper house arms (pivot pin and bushings, or boom cylinder). Jump from upper house to lower carriage (has to jump across the turntable bearing). Lower carriage to outriggers (outrigger pivot shafts and bushing, or outrigger cylinder). Outrigger pad to wood pad to ground. You should be able to see the black mark on the bottom of one outrigger pad where it contacted through the wood. You should be able to see a black mark on the head sheeve where the power jumped from the cable to the boom. You should be able to see that spot on the cable also. You wont see the marks in the turntable bearing. The cylinder marks (if they're hit) should expose themselves in running (exposing the chrome portion) the cylinder and visually inspecting them. The pivot pins will not be exposed unless you take them apart, and won't probably hurt anything. The turntable will be a grind itself to death eventually thing, if it's real bad- imagine a year or two from now. https://www.youtube.com/watch?v=H-d_EeKv_yg When replacing things on the crane- just be thrilled that no one was hurt. When our incident happened, it could have electrocuted 3-4 guys in a instant. No one got hurt and everyone went home. I'll replace some cable, or even a crane, before I even want to think about people.
If you spot where it hit on a sheave or a cylinder, lightly sand or hone that spot. The rough spots on the cylinder will wipe out seals, the rough spot on a sheave will damage the cable etc. If I could see where it arced on the cylinder, I would probably tear down that cylinder and inspect the interior of the barrel, because it would be damaged also.
I saw the aftermath and pictures of a large truck crane on a dealer lot after a rain storm. Apparently it was old enough it had a house lock that was not engaged, the high winds push the boom around and the boom tip contacted one of the three 72,000 volt lines.... it was a melted lump and the tires of course were just charred black soot. The outriggers were up so the current had to have jumped at least one tire to start with... must have been quite a show when it happened.
That would be great Knept. Is this an expensive fix if it continues to be an ongoing problem? I also appreciate the information on the damage that could have been done from contacting the power line. I have priced out some new cable and will inspect the machine closely to see if I can find any of the arcing points. -NickR
I am looking for a jib/boom extension for a grove TMS-640. If anyone has one or knows where one is. I sure would appreciate the info .
https://www.machinerytrader.com/listings/construction-attachment/for-sale/22691751/grove The ad says they have the inner stinger, but the picture doesn't show it. This next one is on ebay, you're going to have to get all the dimensions from the seller and measure out yours to see if it is the right one. https://www.ebay.com/itm/Grove-Jib-Crane/222581711760?hash=item33d2e76390:g:bO0AAOSwDkVaHaHQ Do you have yours yet to get the measurements off of?
Crane Operator yes I have it home. and thank you for the information. I will check into it thanx again
Crane Operator the one of ebay measures 28". center to center pin-pin. mine is 32''. pin - pin. so that one will not work . my fab shop says that they can make it work, but I am not at all comfortable with the idea. so I will keep looking
It would be a big pain to change it to fit, and its probably off a smaller 530 then (the ebay one), so none of your charts would be right. You really need the right one so the charts are correct. What length is your load chart in the crane saying you need? 29'- 51'?
Crane Operator I can take another look. I am sure that the one is the 29-51ft. and I believe that they also made one without the insert. so probably just 29 or so . but I am looking for the 29-51ft Thanx
All Crane also has what you need. Looks like they have the nose insert too, which would be handy once in a while. https://cranenetwork.com/part/jib-s...39---grove-tele-swingaway---fixed-nose/151876 https://cranenetwork.com/part/jib-s...-grove-22039-pullout-section---2-avail/151913 https://cranenetwork.com/part/jib-s...66---grove-tele-swingaway-base-section/151909
Crane Operator I will call there , I have emailed them and either got no response , or the response was this stuff has been sold. I am pretty sure that it is no longer available . but I sure appreciate you looking and I will let you know Merry Christmas