Liftmaster LA400 - RPM Reversal Error

[NotEnough]

Got a Chamberlain Liftmaster LA400 gate operator. It's about 5 years old. Other than replacing a couple of batteries and greasing up the pivoting parts, it's been pretty dependable.

Wife came home and the gate was mostly open...call it about 95%. Came home and opened up the control box. Check that both batteries were at >12 volts. Hit the remote, nothing happens. No click or anything. Manually unlocked it and open and closed it a couple of times. Was a bit draggy so I shot some white lithium grease at the pivot points. Open and closed it manually a couple of times. Swings much nicer. Reset the unit. Hit the remote. Heard a click and then counted 5 flashes. Per the manual that's a RPM Reversal error. Couldn't google up anything on this error other than lots of pages which has the error code table from the manual or were in reference to garage door openers.

The question I have is OK, what does that mean and what should I check next?

Off to bed shortly, but I'll check in first thing in the morning. Thanks in advance.

 

[NotEnough]

I opened up the operator. Everything seems to be in order. No shorted wires, burned switches or stripped teeth.

It barely opens under power, but it will open....slower than 'normal' and just shy of all the way open. Won't close at all. I cleaned and shot some WD40 on the extension arm (the part that moves in and out of the operator). It moves a bit more freely now.

I think it is something electrical. Like the controller is getting feedback that there is too much resistance opening/closing therefore it codes out??? Just a guess.

Anybody have any ideas? My hack tinkering has reached it's end. I need to get it fixed b/c the wife is not liking the manual gate....and it was raining over the weekend.

ANY suggestions?

 

[RollUpDoor]

Call Liftmaster technical support. They will help you solve it.

 

[NotEnough]

No luck with calling Liftmaster. They direct you to a local dealer.

I guess I'm stuck calling out a service guy.

 

[miketyler]

What did you figure out on this NotEnough? I bought a bunch of used parts off of CL to piece my dual gate opener together and today found the same error.

One of my arms apparently builds up heat and throws that error code. When you try to operate it thru the main board, its starts and then stops. You can hear the relay clicking on the mainboard. I presume this is load protection?

I swapped gate 1 and gate 2 plugs on the mainboard to see if the problem stayed with the arm and it did so I guess I am looking for an arm.

Curious though since this is new to me what you came up with as a resolution to yours?

 

[Monchos]

Well I had the same RPM Reversal problem and I replaced the motor of the arm but this did not resolve the problem. I found this page from Liftmaster support center

http://liftmaster.custhelp.com/app/...sion/L3RpbWUvMTM3MzM3ODc4OC9zaWQvUioxV3BOdWw=

and I double checked the batteries and one was giving only 6 VDC. I then replaced both batteries and that solved the problem. You can get the batteries at Radio Shack for $36 each. The gate opener uses the stored battery power to open and close the gates even when connected to the power source.
If you live in a hot climate and the batteries have more than 5 years you have to replace the batteries first and then continue the troubleshooting.

 

[gsims1997]

Well I had the same RPM Reversal problem and I replaced the motor of the arm but this did not resolve the problem. I found this page from Liftmaster support center

http://liftmaster.custhelp.com/app/answers/detail/a_id/5488/kw/RPM Reversal/session/L3RpbWUvMTM3MzM3ODc4OC9zaWQvUioxV3BOdWw=

and I double checked the batteries and one was giving only 6 VDC. I then replaced both batteries and that solved the problem. You can get the batteries at Radio Shack for $36 each. The gate opener uses the stored battery power to open and close the gates even when connected to the power source.
If you live in a hot climate and the batteries have more than 5 years you have to replace the batteries first and then continue the troubleshooting.

Monchos,

I registered an account 10 years after this posting just to tell you thanks for this tip. Our battery was 7 years old before this happened. The symptoms I observed was that the gate progressively closed slower and slower until it wasn't able to close at all and then threw a 93 error code (RPM stall). I disconnected the gate, so there'd be no resistance, still got the 93 error code. I replaced the motor thinking we'd blown out the electric motor (I think the gate is a heavier than the specs call for). I checked the amps on the 12 V (7 Amp) battery and it showed it was only putting out about 3-4 Amps, with 13+ Volts. I pulled the battery, and disconnected the AC power, then jumped the F1 female connectors to a 12V 6 Amp battery charger -- and the gate operated as normal! Thanks a bunch. I was ready to start ripping apart the gear/reducer boxes! I honestly didn't think it could be the battery. It's connected to an AC power source, why would it matter if the battery is dead? My guess is this is so the manufacturer could save a few nickels on circuitry, rather than intelligently switching between Battery and AC power.

Cheers!

 

[nadogail]

Good to know, I wonder where the Radio Shack batteries are now sold?

 

[gsims1997]

Mine was an easy find (sent my wife to the store) at Batteries Plus in Vista, CA. These are a pretty common battery. People put them in go-carts. Should be one close to you in San Diego. 12V 7Amp rechargeable with F1 male terminal connectors. You of course can find the same one on Amazon or order for pickup at a Home Depot.

 

[TexLA412]

Got a Chamberlain Liftmaster LA400 gate operator. ... Heard a click and then counted 5 flashes. Per the manual that's a RPM Reversal error.

@NotEnough, what happened with yours? My LA412 in a simple single-gate setup has very similar symptoms (little/no movement, and 5 flashes). The battery voltage is sufficient (12.6 V each). Inside the arm, I don't see problems with the mechanism. I tested the limit switches and most wires but haven't found the problem yet.

Disconnected, the motor resistance (red and blue wires) is 3.0 ohms.

Connected and giving, the motor current is about 0.5 to 1.0 amps, or up to 4 amps if I hold the manual disengagement switch and the motor spins fast.

Connecting a 12V power supply (actually 13.6 V) did not solve the problem.

Anyone else have ideas?

UPDATE:
After additional troubleshooting steps, including this resource
https://www.justanswer.com/home-imp...r-la400-gate-opener-rpm-reversal-message.html
I tried resetting the limits -- which worked! Apparently the controller had forgotten the limits, or got the wrong limits, so the arm would travel very little. I don't know why it lost the correct limits.

 

[miketyler]

I've since bought a newer setup and today had the same issue occur some 9-10 years later. As above I was able to resolve by resetting the open and closed limits on both gates. Hope this helps someone

 

[miketyler]

Spoke too soon. One of my arms gets the reversing error code 94 just a few seconds into motion. Unable to reset limits for it with that happening. The manual says to replace the Absolute Position Encoder or "APE" but I don't think they sell this for the arm units. They want you to replace the arm.