fANUC OT Mori Fuse blows

Mori Seiki AL-20 with Fanuc OT-Mate control. Fuse "FX14" (1 amp) is randomly blowing after about 30-40 hours. Mainboard, right next to the power supply. Microfuse. Is there power supply voltage that is just a tad bit high?

Anyone seen this in the past?

ca

Reply to
clay
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AL-20 EX OFFSET CURRENT V

Need to have the motor megged if it checks ok you will be replacing the servo amp.

DaveB

Reply to
DaveB

Fanuc error 905. External 24V line. Gee, only the whole damn I/O & control side is 24V. How many switches etc could that possibly be? AND it is very intermittent... Even Fanuc said good luck finding it. I better get a whole box of fuses, or wire in a 1 amp breaker....

Went weeks using a 1 1/4 amp emergency fuse while waiting for the special Fanuc 1A Microfuse to show up, so..... Typical current draw is

0.21A, so obviously it is spiking randomly.

Anyone have some suggestions on what it is most "likely" to be? There are no obvious symptoms. The fuse blows while the machine is idle.

ca

Reply to
clay

You might have an intermittent short in the oiling circuit. That is something that probably cycles on a timer regardless the motion on a machine of your vintage. Cooling fans and chillers are also relay operated.

Reply to
John R. Carroll

Sorry I thought you had alarm #20 DaveB

Reply to
DaveB

Make up some nice long test leads and put a dc ammeter in series with the fuse---carry it around with you while start jiggling switches wires cable connectors etc.

Reply to
Bipolar Bear

or stick in a piece of brass round stock and wait for the magic smoke to point out the problem.

Reply to
Gunner Asch

Gunner:

I think you should of put a smiley at the end of that sentence. Never can tell who might actually try that as a last resort to replace the offending part. LOL

Reply to
BottleBob

Ive seen it done before.

Reply to
Gunner Asch

Clay if you have a ladder diagram for the machine then you should easily find the 24v power supply feed on the first few pages where the 3 ph mains etc are described--there you will find a pointer to the page number where your 24 volt ladder starts and thes pages will show a definate ladder resemblence to an actual ladder with 0v on one side and 24 on the other, find yourself several suspect refrence points and then place some additional inline fuses, does not matter if they are on the zero or the +24 side.

Reply to
Bipolar Bear

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