For the fmmap mmg series, this usually means that the machine enters global security locking mode when the dashboard appears at the same time as al 91 and hints that the traction (trail/drive) is not working。
In the logical architecture of fimap, al 91, although defined as a “brusher abnormal”, as the driver system (traction) shares the master power control module or logical security chain with the brush system, the system will immediately cut the walking power in case the main plate is burned as soon as there is a serious overload of the brush end。
Al 91 core cause of traction
1. Serious hugging of a dishwasher (most commonly)
If brushes (e. G., belts, wires) are completely jammed, the instantaneous current will peak. The master control board (iom board) senses an electrical vagrancy, which is determined to be a hardware short-circuit risk, thus closing all power output, including walking。
Main power fuse or air switch jump
In-house distribution boxes for mmg machines, brushes and drives the sharing of certain large current insurance. If the scrubber is short-circuited, it may lead to the collapse of the fuse on the bus, leading directly to the "show code and cannot walk"。
3. An instant drop in voltage (deficit electricity protection)
If the cylinder is old or the wire column corrosive, the large current that opens the brush will cause the total voltage to break the safety threshold (e. G. Below 20v). At this point, the system gives priority to the error of the high load end (al 91) and also disables walking to protect the cylinders。
Emergency recovery steps on site
Physical relief (cleaning of chassis):
Check thoroughly whether the brush and the wheel have entanglements。
Check if the electromagnetic brakes of the driver (walker) are loose. If the brakes were in manual mode, the machine would also be unable to report errors。
Force cold start (cleaning of logical dead locks):
3. Driver test (without test):
It's a local maintenance proposal
Xian and the surrounding industrial parks (e. G., xiandong, xianxi, zhui) tend to be heavy in terms of dust, which can lead to heavy dusting of mmg-driven heat fans or brusher carbon sluice tanks。
