# Electric scissor lift problem



## amptech (Sep 21, 2007)

I have a Hite Master scissor lift that has got me puzzled. I have never used it in cold temperatures until 2 weeks ago. I was using it to mount some 400W MH flood lights on 30' poles when the temp dropped from 35º to 25º. When the temp dropped it just stopped working. It didn't click when you operated a control-it did nothing. I had to use the emergency release to get it down but it wouldn't move or do anything. I checked every connection and the batteries and everything checked out fine, it just wouldn't work. I finally gave up for the day as it was getting dark, and left. The next day the sun was out and the temperature came back up to around 35º so I went back and jumped on it and hit the controls and it worked fine. Could the soleinoid that runs the motor that drives the main hydraulic pump be that temperature sensitive? It has gotten cold again so I haven't been able to load it up and bring it back to the shop to go through it. It is stored inside where it is but I'm afraid if I load it up by the time I get to the shop I won't be able to drive it off of the trailer. Anybody have any experience with electric scissor lifts in cold weather?


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## paul d. (Jul 13, 2008)

sure do sound like a battery problem.


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## JayH (Nov 13, 2009)

Electrolytes will freeze if the battery is not fully charged. Keep the lift plugged in to maintain full charge when not in use.


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## amptech (Sep 21, 2007)

paul d. said:


> sure do sound like a battery problem.


When it wasn't working I checked the batteries and they were showing 38V on my T5-600. With it not responding I couldn't check the voltage under load but I would think there would be enough there to at least make the soleinoid click. When you have worked it all day and the batteries are getting low that's what it does. I know that below freezing temps knock the batteries down 30-40% but I thought it would at least try to do something. I even plugged it in and started the charger thinking it would warm up the batteries a little but it was still a no go after an hour. If I could be fairly sure it was the batteries I would just swap them out for 6 new ones but I hate to spend the $360.00 and still be at square one.


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## JayH (Nov 13, 2009)

I'd pull the batteries and have them load tested at a local auto parts.


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## paul d. (Jul 13, 2008)

once you get it loaded up, swing by a AUTO ZONE store. they got a load tester. they'll check batteries for free. worth a try.


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## B4T (Feb 10, 2009)

Might have water in hydraulic fluid and it freezes when temp falls.

Condensation can get water into places you won't think of.


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## amptech (Sep 21, 2007)

Black4Truck said:


> Might have water in hydraulic fluid and it freezes when temp falls.
> 
> Condensation can get water into places you won't think of.


But would that keep the soleinoid from even clicking? I can see cold hydraulic fluid making the pump motor grunt but it won't even run.


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## B4T (Feb 10, 2009)

amptech said:


> But would that keep the soleinoid from even clicking? I can see cold hydraulic fluid making the pump motor grunt but it won't even run.


It might cause a loss of pressure in the system which is monitored by a N/C pressure switch.

Stick a screwdriver into the hydraulic reservoir and look for water bubbles mixed in with the fluid.


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## amptech (Sep 21, 2007)

I checked the hydraulic fluid after it was running again and it wasn't foamy. Foamy fluid is a sure sign of the presence of moisture.


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## nolabama (Oct 3, 2007)

Load test your batteries.


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## B4T (Feb 10, 2009)

amptech said:


> I checked the hydraulic fluid after it was running again and it wasn't foamy. Foamy fluid is a sure sign of the presence of moisture.


That works on auto and truck transmissions where the fluid is rapidly agitated.

A scissor lift is a far different animal IMO. 

If the load test comes up negative, I would look for tainted hydraulic fluid.


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## drsparky (Nov 13, 2008)

They advantage of rentals, call them up and they will fix it.:thumbsup:


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## amptech (Sep 21, 2007)

drsparky said:


> They advantage of rentals, call them up and they will fix it.:thumbsup:


I decided to buy one after several years of hassling with equipment rental places. You have to wait on a list to get one. When you finally get one it is a piece of junk that won't hold a charge long enough to keep you busy until lunch. Then you stand around burning daylight waiting for a replacement which is probably also a piece of junk. In 2007 I paid $15k in lift rental. I bought this one for $4k and have used it enough since 01/08 to where if I had rented I would have paid over $12k plus I have rented it to a couple of other contractor/friends at a discounted rate and made back over the last 2 years what I paid for it. I shouldn't complain and just go throw 6 new batteries in it. I guess I'm just too much of a penny pincher.


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## amptech (Sep 21, 2007)

Black4Truck said:


> That works on auto and truck transmissions where the fluid is rapidly agitated.
> 
> A scissor lift is a far different animal IMO.
> 
> If the load test comes up negative, I would look for tainted hydraulic fluid.


Trust me, I know my way around hydraulics. I spent a few years repairing and rebuilding hydraulic motors and hydrostatic trannys.


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## captkirk (Nov 21, 2007)

I agree on the batteries bit.


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## RIVETER (Sep 26, 2009)

*scissors lift*

If your batteries were allowed to get low and then you tried to recharge when they were possibly at freezing it will not take a good charge. Also, if they were allowed to remain low for a long period of time , SULFATION can occur at the plates. That can be reversed with a good battery charger that has that ability.


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## amptech (Sep 21, 2007)

RIVETER said:


> If your batteries were allowed to get low and then you tried to recharge when they were possibly at freezing it will not take a good charge. Also, if they were allowed to remain low for a long period of time , SULFATION can occur at the plates. That can be reversed with a good battery charger that has that ability.


The lift has an on-board charger with a spring-wound timer. It had an 8 hour charge the night before it failed in the cold. I believe, after reading the responses here, that I probably have a few dead cells among the 6 batteries.
Thanks everyone for all the input.


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## Missouri Bound (Aug 30, 2009)

I'd bet it's an issue with one of the safety circuit wiring. Probably a break in the wire which under temperature changes expands or contracts. Has it ever happened at the upper extension of the lift? Only the safety circuits will shut down the lift entirely.


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## Innovative (Jan 26, 2010)

Actually, the leveling circuit is fluid controlled and the fluid froze up.... we have this happen if we used our lifts in big freezers too long. We now only leave them in the freezers for 20-30 minutes, then take them out to thaw.


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## Bob Badger (Apr 19, 2009)

amptech said:


> I decided to buy one after several years of hassling with equipment rental places. You have to wait on a list to get one. When you finally get one it is a piece of junk that won't hold a charge long enough to keep you busy until lunch.


That sucks, if I call by 3 PM I will have the lift I want on the job by 10 the next day.



> In 2007 I paid $15k in lift rental.


The companies I have worked for have spent over $300K a year on lift rentals.



> I bought this one for $4k and have used it enough since 01/08 to where if I had rented I would have paid over $12k plus


But, you are stuck with just one specific size and type of lift.




> I have rented it to a couple of other contractor/friends at a discounted rate and made back over the last 2 years what I paid for it.


Have you talked to your insurance agent about this, if some one gets hurt or killed you can probably kiss you business good by.

Who does the maintenance on the unit?

Are they trained?


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## Bob Badger (Apr 19, 2009)

Innovative said:


> Actually, the leveling circuit is fluid controlled and the fluid froze up


What is a 'leveling circuit' on an electric scissor lift?


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## mattsilkwood (Sep 21, 2008)

Bob Badger said:


> What is a 'leveling circuit' on an electric scissor lift?


 I think he is talking about the out of level cutout switch.


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## amptech (Sep 21, 2007)

Bob Badger said:


> That sucks, if I call by 3 PM I will have the lift I want on the job by 10 the next day.
> 
> 
> 
> ...


I'm not "stuck" with one size lift. It is the size I need 95% of the time. If I need something different I can rent it. Just because I own one doesn't mean I can't rent anymore. And yes, I went over liability issues with my insurance company and my lawyer before I bought one. Renters sign a liability waiver just like you do when you rent from an equipment rental company. I do most of the maintenance and I am trained and still have my certification for repair and maintenance of hydraulics and I am still a certified AWS weldor.


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## Innovative (Jan 26, 2010)

I have never signed a liability wavier when I rent equipment....... Also, if you rent your stuff out, you cant just have them sign a simple wavier, it would never hold up. 
For me, owning a scissor lift is much more economical then renting. Repairs and maintenence are very minor.......a once a year check up with Cat and we have installed 1 set of replacement batteries in 3 years, almost 2600 hours of use. Payment on a new lift is 400 per month and rental is about 800 per month.


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## Innovative (Jan 26, 2010)

mattsilkwood said:


> I think he is talking about the out of level cutout switch.


Yes... when the fluid freezes the lift is dead in the water.............
On Genie and JLG lifts, those are the brands we own. Not sure about the other brands tho.


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## amptech (Sep 21, 2007)

Innovative said:


> I have never signed a liability wavier when I rent equipment....... Also, if you rent your stuff out, you cant just have them sign a simple wavier, it would never hold up.
> For me, owning a scissor lift is much more economical then renting. Repairs and maintenence are very minor.......a once a year check up with Cat and we have installed 1 set of replacement batteries in 3 years, almost 2600 hours of use. Payment on a new lift is 400 per month and rental is about 800 per month.


I don't know about where you rent equipment, but our local rental place, Sunbelt, and United all requires the renter to sign for a piece of equipment when they take it and sign it back in when you return it. Read the "ticket" you are signing. The fine print includes a liability waiver and a damages waiver and yes, it holds up.


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## Innovative (Jan 26, 2010)

Look at the fine print...... the waiver is if you misuse the product,the other section is a damage waiver.......BTW, United and Sunbelt deliver you junk... their fleets in our area are top notch, i dont think any of their lifts are over 3 years old and they usually have 40 -50 different scissor lifts at any given moment.


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## amptech (Sep 21, 2007)

Update, in case anybody is interested.
The problem I originally posted about with my lift turned out to be totally unrelated to the batteries or hydraulic system. It was a bad safety switch. It was a toggle switch with a spring-loaded cover that snapped closed and killed the switch if it was bumped. The switch case had a hairline crack in it. When It got below freezing, evidently it expanded and allowed the contacts to separate. I removed it and replaced it with a mushroom e-stop button. It worked fine last week outside in 20º.


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## amptech (Sep 21, 2007)

Innovative said:


> Look at the fine print...... the waiver is if you misuse the product,the other section is a damage waiver.......BTW, United and Sunbelt deliver you junk... their fleets in our area are top notch, i dont think any of their lifts are over 3 years old and they usually have 40 -50 different scissor lifts at any given moment.


Here's a copy of the back of a typical rental receipt. Note the "save, hold harmless and indemnify" language concerning the rental company. This is one local rental company but United and Sunbelt are nearly identical in their language. And for the record, I did not mean to imply that United or Sunbelt had ever supplied me with junk equipment. Just my local rental place did.
http://i276.photobucket.com/albums/kk29/amptech_2008/rentalagrmnt.jpg


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