Keep getting this brake monitoring shutdown code SHD2700 on an Otis GEN2. Was happening once a months but lately twice a day. Brake monitoring switches seem to work fine, as LEDs illuminate properly.

Is there a way to temporarily or permanently bypass the brake monitoring switches in order to confirm the source of the fault?

Thanks,

Lots for times you will get this fault once the brake/machine gets hot after extended use. Do you have the optical brake switches or the mechanical switches? If you have the optical switches try upgrading to the mechanical ones.

Thanks for the info Magic. the brake switches are optical, one for the emergency brake and the other for the standard brake. tried purchasing a new kit from Unitec, but they insist on selling me the complete brake system for over 15K "CRAZY". I adjusted them to approximately a 16th away. would you know if it's possible to bypass these switches temporarily for testing? as the problem is happening every couple of hours now. Brake relays have already been replaced.

I'm sure there is a way to bypass it but I don't know it. We put on the new switches and added a fan in the overhead and didn't have anymore problems. I know that the two LEDs have to drop and pick at the same time. There can't be any delay between the two.

Thanks Magic, I will monitor those LEDs closely. keep you posted of my findings.

if you have a ovf30 drive, there is a setting in the drive menu to tell the controller if there is a brake switch or not. you can turn it off temporarily to test your switches without the nuisance shutdowns.
we tried to get a switch also, and they only sell the entire brake assy. 15k
unbelievable why won't they just sell the dam switch. we ended up getting one from a otis friend. more then one way to skin a cat. ha ha
do you know which switch is causing the problem? we were having intermittent problems and could not determine which switch was problem, so here is what we did we removed one brake switch input to controller, and then jumped input to the other brake switch input at the controller, so one switch feeding both inputs. we then ran the car to see if it would fault, first time it did not, so reversed above circuit, and it faulted a couple hours later, that is how we determined which switch was the problem. however if you do this, and it continues to fail, the you have a problem with the brake actually picking. in which case 15 k might be needed ha ha

Thanks Vatorgator, good idea about pinpointing which switch is defective. I'll try that out next. Is the drive setting only accessible with the service tool?

yes need service tool,

Duh. I didn't even think of the drive perimeters! Good call Vatorgator!,

Can any of you guide me trough it if I can get my hands on a service tool? Thanks for the help.

Thanks guys, I should be able to put my hands on a service tool tomorrow. I'll have it for the day only. Please see if you can post the instructions at your earliest convenience. Thanks again for your help, it's much appreciated.

Did some more trouble shooting this morning and was able to clear the brake switches. I found that the "LB" relay is not picking, therefore the brake switch fault appears.

The "LB" relay seems to be controlled by the drive board. The drive is actually faulting out showing "M421" then "!04A" I have no idea what these codes are. There's a soldered relay "relay 2" on the drive board that has one N/O contact looking pitted, don't know if it has anything to do with the brake circuit.

Everything seems to be pointing to a defective drive board. The drive model is ACA2129OBJ2. Unitec wants to sell us the complete drive $10K,not just the board.

Any input or guidance is appreciated.

Check with Access Electronics to see if they can repair the board. Bet they have seen this before.

Thanks Rolly, I'll give Access Electronics a call tomorrow morning.

access has fixed ours and do a great job, however M421 is telling you to check the fault log in the drive for further info. you plug into drive and press M 4 2 1 this will display the fault log. then you can further try and decipher what is going on. you will need to borrow that tool. i would not necessarily say the drive is bad, until you know what the fault code is telling you the !04A is telling you there is a drive fault and need to check the log. if you do indeed take the drive out, as a precaution, it is always a good idea to record every parameter in the drive. sometimes when they get repaired parameters can be wiped out or changed inadvertently. does happen, and then you are in for some real fun. also in the drive menus there is a menu to check the output that turns on LB relay you can then see if the drive is actually trying to turn on the output for LB. what exactly happens? does it pick up the direction relays and fault out immediately? what kind of fault are you getting on the MCSS log? lot of things to check before you drag the drive away.

Thanks for the pointers Vatorgator, I will have the service tool tomorrow and verify if I can see what the faults are.

From my troubleshooting earlier today, I can confirm that a direction is picked, although the "BKR" green LED on the drive does not go on and it faults out.

The few times that it works, that "BKR" LED goes on in the same time as the "LB" relay. It seems to be the output to drive the "LB" relay.

Get back with some more info tomorrow.

Thanks again for all your input.

If the controller is preparing to run and that BRK led does not turn on then the LVIB board is bad.(probably that soldered on relay) You can try switching that board with another in that group to confirm. The LVIB( low voltage interface board) is the lower board with the LEDs on it.
I would still look through the fault logs for the drive and Mcss

+1 on getting the parameters.

Fault on Drive is "Brake State" fault on controller is "MLS rdy/brk err 2700 SHUTDOWN".

The actual problem after all was that the drive was not initiating the brake and faulting out.

Spoke to Access Electronics and they are 100% sure that it's the LVIB board on the drive acting up, most probably a bad micro relay. (seems to be common issue with these drives) they recommended to ship the drive out to them for a complete overhaul.

Waiting for the drive back so I can confirm the results and close this thread.

Thanks again for all your help Magic Smoke, Vatorgator and Rolly.

Working on the same fault. I was fortunate enough to watch the LED for the Emergency Brake sensor flicker while stopped with no demand. This one has the newer type of sensors (not optical).

When BE flickered for 30 seconds or so, it registered a brake state fault, remained parked at the floor for less than a minute, and then proceeded to answer my calls.

Hope that helps.