840C Alarm 3 Fan Failure

Hello,

I have this popping up on a machine we have, all the fan i can see are spinning and the ones in the control unit are spinning to.

Are there any more fan i should be looking for?

Ones i have see are two on the door, two inside the machine, and 4 inside the control units

Thanks

Hello,

Which is your control system. You have seen fan rotation, but are they running at their full speed. Do you see any dust accumulation on fan? Try to use clean the filters fins & protective wire mesh by dry brush or with vaccum cleaner. (Of-course in power off condition)

Please provide the detail MLFB number so as to sort out the problem, i.e. is it fan speed problem or temp. sensor problem.

You may have non-original fans fitted - they might not have fan speed monitoring built in.

If you replace the fans with units that do not allow for fan monitoring you can switch off the Fan Failure alarm by setting DIP Switches  ( or wire links on the older units ) on the Central Service Board - see the Sinumerik 840C Interface Description Part 2. Connecting Conditions manual chapter 2 pages 2-198 to 2-213.

Remember - when you remove the Central Service Board all RAM Data will be lost - you will have to re-load all data from the MMC CPU back into the control.

Thankyou. I have now found the issue.

Do you know where i can buy the fans for the FANCOOLER MODEL FC.12?

Thanks

 Hi, from your picture post, I know you have 840C control, alarm  3 Fan failure is told you--one of Fan unit on the top of 840C control rack no good--small system has 2 tires--2 fan units, large system has 3 tires--3 fan units.with this alarm Normally you can still run your m/c, some m/c builder design when one cycle finish you cannot start next until you fix the issue.

you can shut off power remove all fan units --clean the fans with safety contactor cleaner then dry with soft air blowing. also pay attention to the 4 pins of fan unit contactor to the rack--unit can be removed by pressing 2 clampers then pull out.

If you cannot fix your issue , or need spare pars--Fan unit , PM me,

PS: I found more information for you --see picture

You need check-clean-or replace fan unit 1st. and there is very less chance if you are unlucky --the Fan monitoring system defective, for that you need repair the monitoring system.

declanhughesipel

Hello,

I have this popping up on a machine we have, all the fan i can see are spinning and the ones in the control unit are spinning to.

Are there any more fan i should be looking for?

Ones i have see are two on the door, two inside the machine, and 4 inside the control units

Thanks

declanhughesipel

HI,

The fans were broken so i had to replace them but with fans with out a sensor cable, how do i bypass the alarm?

Thanks

 Hello,

Please do not think of running of machine by bypassing this fault. It may lead to failure of further hardware component. Please expedite the matter & get fans at the earliest.