Email
Password   Forgotten?
Remember me
Marketplace
Business Directory
Discussion Forums
Home
My profile
Search
Spec-Checker
Industry News
Events Calendar
Jobs & Resumes
Photo Galleries
Home | About us | Advertise with us | Tell an associate | Contact us | Site map | Help 
Search  
DISCUSSION FORUMS : Forkliftaction.communicate
Forum: Mechanical Troubleshooting
Brand: Crown - Model: RD5020-30
Number of messages: 18
START MESSAGE:
brian_k
Virginia, United States 		Over the past two months I have had 6 access 3 traction controllers go bad on 6 different  lifts. I can not find the problem. Everything seems to be good on the lifts. I can not find anything that may be "spiking" the controllers. I'm trying to find a common link. Does anybody know if theere is any outside causes like a radio waves or such? These things are too expensive. to keep this up.

Posted 26 Feb 2005 06:29 PM Reply  Report this message
REPLIES: Sort replies by
danny_e
Illinois, United States 		are they picking up mylar or any type of plastic film ?

I have had the same problem but only where the film was present, I believe that its simply static electricity building up on the machines, but again it's only a guess

Posted 27 Feb 2005 05:46 AM Reply  Report this message
brian_k
Virginia, United States 		Yes . we are always digging plastic wrap out of the wheels. I think the lift rivers try to run over this stuff

Posted 4 Mar 2005 04:10 AM Reply  Report this message
Al_S
Alberta, Canada 		To Brian,
Maybe your problem is temperature related. The new mosfet controllers generate a lot of heat and some manufacturers are not mounting the controller to dissipate heat correctly, make sure there is an adequate heat sink and the mating surfaces are smooth and employ a heat sink compound such as white lead. Not unlike mounting a heat sink to a CPU.

-------------------------
Alberta Forklift Safety Council Serious about safety!

Posted 4 Mar 2005 05:13 AM Reply  Report this message
Jules
Rhode Island, United States 		If it IS static building up, can you install a static strap or a dragging chain to help dissipate the charge?
   Just a thought,I had drive units on some Crown order pickers dropping like dead flies and couldn't figure for the life of me what was going on,until a fellow service tech did an after hours emergency service call during the third shift.He observed the drivers sliding their forks under the drive unit of another lift and bumping it up and down to play around with the other driver.Come to find out they all did it to each other during the graveyard shift.Heads rolled over that one.What I'm saying is don't think the drivers can't be doing something you havn't thought of either.The problem is too widespread.
            Jules


-------------------------
It seems the harder I work,the more lucky I become.

Posted 4 Mar 2005 09:39 AM Reply  Report this message
Liftdoctor
Indiana, United States 		I have not heard of this, however all of these modules go back to Crown to be rebuilt of replaced.  Get with your Crown dealer and have them find out what was wrong with the next one that goes bad.  They have access to Crown technical help which provides a large data base of causes for failures.  If there is a common problem, Crown can give you some insight as to what the cause may be.  Also, I recall some sort of modification you must add on newer controllers.  I believe it was some sort of wire that is supposed to dischage capacitors when the truck is truned off.  Do you have any two way radios or RF units the operators use.  I recall hearing about one customer that had the trucks shutting off for some code when the operators key the microphone on the two way radio laying on the dashboard.  Look at ANY accessories that may have been added such as lights, strobe lights, and back up alarms.  The strobe lights and back up alarms should have suppressors.

If these are older Crown RR5000 models, Crown has made upgrades to improve reliability, but they are not saying what they are.

The most basic step I always forget it to check for voltage to the frame.  Stick one end of you voltmeter in battery negative.  With the truck operating, you should see anywhere between 5 and 30 vlots on the frame.  If it is 0, you have a negative shorted to the frame.  If is is battery voltage, you have a posotive shorted to the frame.   You must get rid of shorts to the frame.    Crown will tell you to get the resitance between any component and the frame to be 50,000 ohms or greater.  I have found that anything above 2000 or 3000 ohms is OK.   This is not a hard and fast rule.  I have just found this resitance reading to usually work for me.  

I have run accoss speed nuts that are pressed into the frame raised up beyond the surface where the modules mount.   When you tighten the module down, it is stiill not flat against the frame.   The module does not dissipate heat to the frame like it should.  If you find this. grind these flat with the frame before mounting the new module.

I believe all newer Crrown RR5200 models have fans in the doors.  There is a fan kit available.  If your trucks have no fans, consider installing them.  Anything to keep the truck cooler will help.   Crown has said that heat was a main cause of failures in their early 5000 reach trucks.  


And lastly, did any of them fail with the truck parked next to a battery charger?   The capacitors in the modules will hold enough voltage for about a minute to fool a battery charger into thinking it is plugged into a battery.  If the operator plugs a charger into the truck instead of the battery,as soon as the charger kicks on----ZAP and you lose a module or two of three.

Modified 5 Mar 2005 12:03 AM
by poster. 		Reply  Report this message
brian_k
Virginia, United States 		Thanks guys for the advice. So far no good. These lifts are used in -10 freezers and +34 coolers. They all have been mounted with heat sink grease so heat is really not an issue here. The batteries are removed from the lifts before they are charged. The pickers use VMU's that are RF but in 5 years I would have thought that we would have had trouble with them before now. At least two of the lifts, I'm sure has a short on them but damn if I can find it. I have spent too many hours looking for shorts. I've checked for battery voltage leakage and none are too bad not more than 5 volts.  My FSM has called for a Crown Tech to come in and see what he can find. Crown told me that they can T/S these with a lap top. But please if anybody else has any more ideas fell free...please. As far as the drivers well their favorate past time here is "bumper cars" with 12000 lbs lifts. The dock supervison does'nt seem to mind though but when they tear up a lift its our fault, I don't know how but it is. I'm thinking some of the rough treatment that they get are also part of the problem.

Posted 5 Mar 2005 05:43 PM Reply  Report this message
Liftdoctor
Indiana, United States 		Brain,
Are these Access modules all failing with the same malfunction or code?   I would think the bumper car thing could cause a lot of static discharge when they hit.  

You could try cutting down the travel and acceleration speeds and see it this helps.  There is always the possibility that operators are getting into the computers and changing the settings.  I have seen this many times.   They screw things up to the point the trucks will not run.    There is also the possibility that someone has figured out how to vandilize these by discharging a capacitor or hooking some part of the truck,s electrical system to 115 volts or something like that.

There is little I know of you can do with a laptop besides update the software.  I am a Crown dealer tech.

Try the phone number in the front of a Crown manual, call them, and see if they can help.  I have always called them as a tech.   Not sure of what they will do for a customer.  If you give them serial numbers, they may help.

I am SURE they will tell you to get rid of the shorts.   I can go into a whole discussion on that, but I have never not been able to find a short to the frame.

Posted 6 Mar 2005 09:20 AM Reply  Report this message
MESLlc
New Jersey, United States
Six Access 3's in six different trucks.  
Are they all the same age and approx the same hours?  Is it 6 out of 6 or 6 out of 20?

What were the codes, all different or the same?  Are they even related?

If you're not blowing the replacement Access's that you installed, you're probably sweating over nothing.

Running them in the freezer and cooler pretty much eliminates the overheating problem. Unless it has been updated, the 5020 wouldn't have the door fans or the brake shroud removed.  
Modified 10 Mar 2005 04:26 AM
by poster. 		Reply  Report this message
brian_k
Virginia, United States 		Its 6 trucks out of 28. 3 of the lifts are repeats and of them one lift has blown 3 access's, that one is out of service till i can figure out whats going on. I've tried calling the number in the manual, have done this in the past over other items, and have tried everything thay have suggested still nothing. ASfar as the codes one lift had a 327 code before it died and the others will on go to "test" and will not complete the power up. I've run through the power up circuits and everything seems to be working. Is there anyway to bench test thses things? Seems like there should be a way to test them in the field with out having Crown rebuild them charge me out the ying yang. Replacing just one blows 25% of my monthly budget ( I work for a cheap company if anything cost more than a $1 they flip out). Again thanks guys for your help. A Crown tech was coming down from Ohio but it seems he got sick at the last monment.

Posted 14 Mar 2005 08:40 AM Reply  Report this message
opus
Ontario, Canada 		brian,

the code 327 has a tie to your 1A contactor.  We experienced a similar problem, however only on 1 truck.  Access 3 cards were replaced but continued to fail.  The contactor looked good and upon disassembly for internal problems nothing could be found.  We replaced the tips and the truck never ated up again.  You may want to ensure the contactor has not been overlooked, even replace it, as I mentioned the contactor on the 1 unit showed no problems with the contactor.  It may be bad or weak coils.  It is a small cost to pay to replace contactor ,as opposed to replacing ACCESS 3 Modules.

Posted 17 Mar 2005 11:38 PM Reply  Report this message
MESLlc
New Jersey, United States 		Have you checked the power cable going to the Drive motor  fields.  I've seen them fatigue at the lug crimp on the motor end of the cable.

When you test for your short to frame, be sure to plug into the power cables after the ED Contactor.

My next step would be to swap the drive motor into a lift that has been running.  

Also I would check the traction fuses and mke sure someone didn't install too much fuse after a failure.



Posted 18 Mar 2005 02:07 PM Reply  Report this message
Liftdoctor
Indiana, United States 		Brian,
You made the comment above that some have shorts to the frame but you can't find them.  You must find them.   I agree with the comment above about checking for shorts after the ED contactor.  As a matter of fact, with the battery unplugged, stick one end of your ohmeter on the frame and the other ANPLACE in the electrical system.  If you see anything less than 2000 or 3000 ohms, you need to find the short and get rid of it.  Also, swap your leads when doing this.  If your have the black lead on the frame and see a short, do the test again with the leads in the same place but with the red lead on the frame.  The voltage in the capacitors in the module may give you a false reading.  The fact that it won't power up tells me you have blown the microprocessor.  This leads me to think you have a short to the frame, short in the wiring,  or some sort of electical noise blowing the module.  You can blow the drive transistors in the module from a shorted motor or operator abuse, but the microprocesor should still be giving you a code.


  When the thing gets to the point where is will not power up, you may be able to read code from the light flashing on the controller.

As far as the ED contactor goes, there may be a software upgrade to give more life to these.  Also, software upgrades may give more life to the module. I have other techs tell me that after a software upgrade, they have noticed the acceleration slow down. Crown would need to come and do this with laptop computer.   Contactor life on the larger, wider,  5000S models was a real problem.   Don't replace the tips, replace the entire contactor.  Some the contactors Crown sells are only $15 or $20 more for the entire contactor than if you just bought a tip kit.  

There is no way to bench test the module.  About the only way to bench test it is stick it in an operational truck and see if it works.  Can't say it won't blow another module by doing this, but a lot of us at the dealer have done this and we haven't blown another module yet by doing this.  Be glad it isn't a Raymond.  You don't go module or ciruit board swapping on their reach trucks.  One bad board can take out 3 more.

I still would not rule out looking for good contact between the module and the frame of the truck.  Anything you can to to eliminate heat will help.  Crown did have a heat problem with these trucks.

Modified 20 Mar 2005 00:31 AM
by poster. 		Reply  Report this message
doyle_b
Ontario, Canada 		Brian Al is on the right track. It's sort of a heat issue. The problem is most likley in the traction motor or motor circuit. Before you go chasing ghosts check for shorts and grounds.(the WHOLE truck) Then get your crown dealer to send in their tech services guy with a lap top and down load the latest version for your controllers
The newer programs recognise the changes in the motor if they are not too far gone. Crown motors will show unbalanced fields. Most motor shops won't go looking for this. The easy cure is get a new motor from Crown. But check your programs first.

Posted 24 Mar 2005 03:33 PM Reply  Report this message
brian_k
Virginia, United States 		Thanks guys, We just had the software updated last year to version 13. Had to when we couldn't get anymore the older square encoders. I have not found the shorts that anybody has described yet. Have been busy with other issues here. But so far all my ohm test have shown at least 20000 ohms with an anolog ohm meter.

Posted 25 Mar 2005 09:08 PM Reply  Report this message
brian_k
Virginia, United States 		yes they did Katrina but on two of them I had disabled the circuit due to an earlier problem. Right now I'm hoping that Crown can tell me somthing when they get the units. I have replaced all the bad ones and so far so good. Maybe it was just bad timing and bad luck..lol

Posted 11 Apr 2005 08:52 PM Reply  Report this message
SirWorkalot
Tennessee, United States 		something that i did not see mentioned in any post, but dont forget to check for shorts in the drive motors,Crowns use a bushing at the drive unit end,if the bearings in the mdu get worn and the armature bushing on the motor is worn,you stand the possibility of a armature to field short only when the armature is turning, if this was the case you should experience a code in relation to field or armature shorts, something to consider

Posted 14 Oct 2008 12:39 AM Reply  Report this message


Forkliftaction.com accepts no responsibility for forum content and requires forum participants to adhere to the rules. Click here for more information.
FORUM GLOSSARY
Click for description.

FORUM
DISCUSSION
MESSAGES
NICKNAME
SIGNATURE

FORUMS
Discuss: Industry News & Whispers

Discuss: Conferences, trade shows & other events

Discuss: Mechanical Troubleshooting

Discuss: Technical arena. Did you know? Who knows?

Discuss: Machines. Forklifts, stackers, telehandlers, container handlers and reach stackers

Discuss: Business issues

Discuss: Safety, training & legislation

Discuss: Fun at work
©Forkliftaction.com
Privacy policy
Related links
Site map
About us
Marketplace | Business Directory | Discussion Forums | Spec-Checker | Industry News | Events Calendar | Jobs & Resumes | Photo Galleries
Forkliftaction.com – PO Box 1439, Milton QLD 4064, Australia