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Genie TZ34/20 Motor Controller

brevee12

Member
Joined
Jun 26, 2020
Messages
11
Location
Iowa
I have a Genie TZ34/20 that is having an issue with the motor controller. I got a new one in the mail and installed it. It ran for about 20 seconds then it stopped and hasn't worked since. I'm at a dead end on this. Hopefully someone here can help.
 

Engineer44

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Nov 30, 2017
Messages
60
Location
Portland
Did you ever make any headway with this? I have a slightly older machine than yours (TMZ 34/19) but have a reasonable understanding of the motor controller function. I imagine your controller is at least similar. Dave.
 

brevee12

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Joined
Jun 26, 2020
Messages
11
Location
Iowa
Yes and no. I took the old controller off of the lift and tore it apart. (The 3rd one I've had apart) it was noticably cheaper in build quality and waterproofing which leads me to believe that the heavy rain I had gotten the night before is what fried it. I ended up upgrading to the Curtis motor controller to align with the parts manual info. (Even though all the technical data about the motor controllers is referencing the old style).

Since then it has worked fine. Well, the motor controller that is.... It now has a hydraulic leak on one of the outrigger cylinders. If it isn't one thing it's another! I guess that's what I get for buying an old used/broken down piece of equipment.
 

Engineer44

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Nov 30, 2017
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Alright, good, at least you’re functional again. Glad you figured it out. The Curtis controller is what mine has and what I’m familiar with. I know what you men about buying a lift that wasn’t well cared for. Can be lot or work to get it clean and reliable again. Dave.
 

brevee12

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Joined
Jun 26, 2020
Messages
11
Location
Iowa
Update.

Used the lift all day yesterday. No issues. Forgot to charge it overnight. When we got to the job today it ran fine but I decided to plug it in since it had run a whole day already. Shortly after that, it quit working. No motor movement at all. I opened up the motor controller and found a mosfet blown out. Why would charging the batteries while running it do this? Any ideas?
 

Engineer44

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Messages
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Location
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Hmm, I wouldn’t expect the charger to have caused this unless it’s over-voltage or is not regulated well enough and is putting out square waves that your motor controller can’t tolerate. Does your lift have a high current contactor upstream of the motor controller so that the controller doesn’t see battery voltage unless you are commanding a function. It was an upgrade for the older machines but yours may already have it, stock. Your motor and pump are probably OK since it was all working OK before this incident. But, ouch, those controllers aren’t cheap.
 

brevee12

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Jun 26, 2020
Messages
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Location
Iowa
I don't have a contractor on mine. It's a 2006 model. I'm not sure when that upgrade came out. Honestly there doesn't seem to be any information that I can find from genie regarding that or the motor controller upgrade. Or why they were upgraded. I kept some of the old broken controllers. I'm hoping to steal a mosfet off of one of those and solder it into my newer one that broke. Might be a fools errand but it would be much cheaper if it works!
 

Engineer44

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Nov 30, 2017
Messages
60
Location
Portland
Don’t know the answer but I’m wondering if these lifts have a low voltage inhibit so that it won’t try to run on low voltage. Low voltage is terrible for motors and controllers because they’ll draw more current under those conditions. Wondering if your batteries were discharged enough for this to be factor. But it doesn’t make sense they’d design a machine that would self destruct if the battery voltage gets sufficiently low. Just thinking out loud.
 

brevee12

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Jun 26, 2020
Messages
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Location
Iowa
Yeah I'm at a loss as well. This is a picture of the motor controller. It's trashed. I wish I could buy just the board pictures and not the whole thing.
 

Engineer44

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Nov 30, 2017
Messages
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Location
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Ouch, that burned the circuit board pretty good. I am assuming your lift has a large fuse (275 Amp) and that it’s good and that it’s in the circuit? It would have been nice if that fuse had opened rather than destroying your controller. I looked at the Curtis docs, FWIW they do have a low voltage cut-off. It drew a lot of current for some reason. I’m also assuming the controller is bolted securely to a flat metal surface as that acts as a heat sink for the device. All the connections from the batteries good, connections to the pump motor clean and tight, grounds clean and tight...
 

brevee12

Member
Joined
Jun 26, 2020
Messages
11
Location
Iowa
The fuse is bypassed at the moment. That's how it was when I bought it. Ive ordered a couple fuses now. I'm guessing that it is going over current for some reason and that is what is causing that board to cook. Just not sure why that would happen? It was bolted to the front panel of that motor housing area. It has a little switch on it for 300A or 360A. Not sure if I would have moved that to 360A if that would have prevented this?

The motor itself is brand new also sp that shouldn't be pulling extra current because of worn out brushes or anything like that.

Do you mind linking those documents you looked at if possible? I'm having a hard time finding info on that.
 

Engineer44

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Nov 30, 2017
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I don’t think I can upload files from my iPad but I could from my desktop when I’m home. Or I could email them to you if you’re OK posting your email.
 
Joined
Jul 17, 2020
Messages
6
Location
Portugal
Hi.
It runs on 24V?
If so, check batteries with a meter. Should be around 6,5 V each fully charged. Check density of electrolyte (green in each element on all 4 batteries). Check voltage when charger is plugged. Should rise to around 7.
Charger must shutoff automatically when batteries charged or it will cook them off along with electronics and so on.
I have seen a lot of electric machines break because of faulty chargers or wrong ones with wrong charge cycles setup.

Good luck
 
Joined
Jul 17, 2020
Messages
6
Location
Portugal
Another good rule of thumb. Avoid using the machine while charging. It wears batteries quickly.
Most equipments have an interlock while charging to avoid abuse, especially in rental companies.
On good working batteries and charger, a fully charged machine, used on normal working conditions should be more than enough to a full work day.

Regards
 

brevee12

Member
Joined
Jun 26, 2020
Messages
11
Location
Iowa
I was told the batteries were new when I bought the unit, and they have seemed to perform well during the times I've been able to use it. My main concern at this point is that I don't want to keep frying motor controllers every couple days. Just judging by the sequence of events it leads me to believe that plugging in the charger is what made it fail. I'm just confused as to how that would happen. If I just can't charge it while using it that's not a huge problem. The fuse that I had been missing is what is supposed to prevent this from happening correct? So I should be safe to run a new motor controller as long as I get that fuse in first. Or should I also be looking at that contactor upgrade as well?

I also replaced the charger that came on the machine because it wouldn't charge the batteries. The new one has the wiring for an interlock but I'm assuming that needs to be run to the control panel to be able to be used. I don't see anything in the parts or service manual regarding this however so I'm not quite sure what I would need to get that hooked up.

Engineer44. My email is brevee12@gmail.com. If you have any info that you are able to send me on that controller I would appreciate it.

And thanks both for the input. I'm a painting contractor by trade so a lot of this stuff is above my pay-grade. It's sure helpful to have knowledgeable people to ask questions too.
 
Joined
Jul 17, 2020
Messages
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Location
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Is it a Delta Q charger? If so, be sure it is a 24V one. The 48V ones look exactly the same, case and all.

Fuse is to protect the controller but most times when it blows it's already too late, especially with that high Amp. Kinda like engine oil pressure sensors or temperature sensors. If lit by lack of oil or overheat, you can be 99% sure you already wore the engine down. That's my experience, working on rental companies and doing jobs on my own.

We need to start troubleshooting the problem somewhere so the best thing is to be sure the charger and batteries are in top condition.
Next thing, I would check if pump motor is not being overstressed causing high heat and high current flow. Check If the machine is sluggish hydraulically or has a hard time raising secondary boom.

I have worked on a TZ-50 before so I'll try to help you to the best of my knowledge.

Can you give serial number of the machine? Genie revises wiring schematics a lot and introduce new stuff often to improve equipment.
 

Engineer44

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60
Location
Portland
As I said in an earlier post, don’t know but it’s possible the charger is not filtered/regulated well enough for this application. The motor controller switches those mosfets on/off to enable and control the speed of the pump motor. The controller may not be able to tolerate any spikes or square waves that may emit from the charger. Once the controller fails (not necessarily from over current) it is shorted and draws current until it burns open because there’s no fuse. The fuse will also protect wires from burning open and catching the machine on fire. It sounds like the charger does charge your batteries OK though. And if you can use it all day the batteries and the pump motor are likely OK. At this point I might install the correct fuse, a new correct controller, charge the batteries when the machine is not in use, and use it. If that works OK, look into a different/better/correct charger. I’ll email you the docs on the motor controller and the Genie contactor upgrade kit.
 

brevee12

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Joined
Jun 26, 2020
Messages
11
Location
Iowa
The unit is a TZ34/20 Serial # 3406-264.

Could an issue in the ground control box cause something like this? I have had to do quite a bit of re-wiring in there to get everything to match the wiring diagram. Whoever owned it before me had no clue what they were doing in there.

Engineer 44, thanks for the emails. That controller looks like it is the older style that my lift had when I got it. I upgraded to this, https://www.ebay.com/p/833062674. This is what the parts manual directed me too.

Here is a link to the charger I bought for it. https://www.amazon.com/gp/product/B07X135RKC/ref=ppx_yo_dt_b_asin_title_o04_s00?ie=UTF8&psc=1
It also matches the parts manual info.

I haven't checked to make sure the batteries are correct yet. Is it possible they are putting out to much current or something? My guess would be that they are fine because they had worked fine the whole day before.

I've also looked and looked for information regarding upgrades and revisions and I can't find any sort of list of revisions or anything. Even the documents that detail the installation of the new "upgraded" controller that I bought are only available if you buy the kit. I couldn't find them online.

I'm assuming I would need a scope to check the wave form of the charger and verify that it is compatible with the controller and everything. At this point I only have a cheap clamp meter.
 

Engineer44

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Joined
Nov 30, 2017
Messages
60
Location
Portland
I wouldn’t think anything in the ground control box would cause the type of failures you are seeing. The motor controller always has battery voltage and it applies it to the pump motor when the enable command is sent from the ground or platform controls. Not much involved there except the batteries, the heavy wires, the controller, and the pump motor. The batteries are fine, they can’t put out too much current. As long as they collectively provide 24-volts DC to the system the bigger the batteries the better. I see what you mean about the motor controller, at some point Genie went to a different model controller. What model Curtis is the new controller? I also know what you mean by not being able to find the manual/instructions for the newer controller without buying the kit. When I installed my contactor kit I sourced my own parts and got a manual from another member on this forum that had purchased the kit. Perhaps a member might share that document with us. It also looks like you bought the right charger. It could all come down to just making sure not to operate the charge when using the machine. Mine does not have an interlock to prevent that but maybe yours did originally? Keep us posted. And put that fuse in!
 
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