I have 3 large and long (20') pumps. Only 2 are needed for full load. Someone asked me "How long do they run before they fail?". I'm trying to go back to 1999 and figure it out.

PI - I have 1 good point on each (motor winding temp) when the temp rises over 115F, it's in service.

Excel - Can I assign 1 for every hour that averages over the 115F and tally up the hours during each year (or between each failure) to figure it out. I'm not that good at excel. So make it an easy read.

I usually don't dive into it this deep. But with 3 pumps it is interesting. "A" has been failing 1st. Then it remains OOS until another pump gets in trouble. "B" runs the most and has the most maintenance history. "C" fails the least.

So how many hours are they running between failures?

Thanks!!

Hello CBM Novice,

I hope I understood your question right.
You are tracing the motor winding temp once each hour.
You say that if you see a temp higher than 115°F the pump is running.
I assume that the pumps are running for long time (multple hours) without switching on and off.
Then the data could be evaluated for the calculation of operating hours.

By checking the run time and the fault time you can calculate the operating hours in between.

That is what I'm trying to do. But my question is based on the software programs doing the calculations for me. Rather than me looking at a ten year trend and adding up the hours the pop up over 115F.

Excel - Has the ability to pull the motor winding temperature from our relay system by accessing a program called PI.

I know excel can cut off (and capture) any temperature level I choose.

IE.
If = or > 115F set to 1
If < 115F set to 0

Then I can add up the ones.

Question - What part of the equation is needed in the excel cell to make >115 = 1.

The equation below will capture the 1 hour average from the PI tag in cell A5 based on the start/stop times in A1 and A2. A3 determines the amount of averages (60m = 60 averages in 1 hour)

=PICalcDat($A$5,$A$1,$A$2,$A$3,"average",1,0,)

I didn´t figure out what your problem is exactly but I would bet that you are looking for a formula close to the one shown in cell H7.

Hope it helps.

Rui

This message has been edited. Last edited by: <Rui Assis>,

Temperature_above_a_limit_1.xls (66 Kb, 15 downloads)

I am sorry but I modified the Excel file in my last post. Please download it again.

Thanks

Thanks Rui.

I got the new file.

At 1st glance this looks like it will do the job.

It took me 2 days to figure out that a pump failed after 560 hours of operation (23 days). With 2 repairs only 9 months apart.

This Christmas I'll send you twice as much as last year!

Perhaps this other file (with a moving average of the n latest readings) is closer to your requirement...

Regards

This message has been edited. Last edited by: <Rui Assis>,

Temperature_above_a_limit_2.xls (124 Kb, 21 downloads)