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#26243 03/20/19 07:52 PM
Joined: Nov 2016
Posts: 2
K
stranger
stranger
K Offline
Joined: Nov 2016
Posts: 2
I have a 311 gem with a drive flashing !B1A
Also the fault on my service tool says precharge dc low
Can’t find what this means can someone help
Thanks

kbjr #26251 03/21/19 01:07 AM
Joined: Apr 2014
Posts: 280
H
Engineer
Engineer
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Joined: Apr 2014
Posts: 280
After a full power down and reset of the MCSS, does the fault still exist?

kbjr #26281 03/23/19 01:30 AM
Joined: Oct 2012
Posts: 262
P
enthusiast
enthusiast
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Joined: Oct 2012
Posts: 262
Whats the fault number?

kbjr #26283 03/23/19 02:15 AM
Joined: Dec 2015
Posts: 1,766
Likes: 11
I
ElevatorPractitioner
ElevatorPractitioner
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Joined: Dec 2015
Posts: 1,766
Likes: 11
Most AC drives charge the DC buss through a resistance of some sort until it reaches a set voltage where the resistance is bypassed to fully charge the buss. Otis calls this precharge and once the parameter M1 pick V PU is reached, the M1 contactors in the drive picks to bypass the resistor and charge the buss all the way.

kbjr #33736 08/24/22 04:13 PM
Joined: Aug 2022
Posts: 1
B
stranger
stranger
B Offline
Joined: Aug 2022
Posts: 1
Currently dealing with this same issue. I replaced the 4 capacitors as a starting point but to no avail. Any tips?

kbjr #33765 08/27/22 12:32 AM
Joined: Dec 2015
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I
ElevatorPractitioner
ElevatorPractitioner
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Joined: Dec 2015
Posts: 1,766
Likes: 11
The drive needs to be sent out for repair.

Last edited by Indirtwetrust; 08/27/22 12:35 AM.
kbjr #33768 08/27/22 04:56 PM
Joined: Feb 2015
Posts: 81
B
journeyman
journeyman
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Joined: Feb 2015
Posts: 81
I can get these rebuilt. PM me with pics of data tag for quote.

BillS #33777 08/29/22 01:11 PM
Joined: Apr 2010
Posts: 220
S
bangyourheadhere
bangyourheadhere
S Offline
Joined: Apr 2010
Posts: 220
Access electronics out of Waldorf MD does a good job on these. I have replaced several of these over the years.
301 -645-1733

kbjr #33830 09/05/22 09:29 AM
Joined: Sep 2022
Posts: 1
E
stranger
stranger
E Offline
Joined: Sep 2022
Posts: 1

!B1A
i need your help to solve this problem
There are almost no parts left on the power floor that we haven't replaced, but the fault continues.


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