problem increase amps cooling tower

[Imam purnono]

we have a little problem at the fan cooling tower system,a story is;
after complate instaled and start up we setting 18.5 amps in blade angel 20' at 2 month ago
and than stop running for 2 month,
while start again after two month stop the amps increase till 28.1 amps.
the motor to fan conneted with 6 belt.

why it's happen.

 

[James]

I would be checking the following

Phase voltages when running, a drop in voltage will cause an increase in amps

Check amps are the same across all phases

Check for any physical resistance to movement, I.e bearings etc.

Any significant changes to duct work could increase the power required to push the air through the system.

If it is controlled by a variable speed drive, has the set speed been changed?

 

[Bobster]

So has it been sat stationary for 2 months?

Any maintenance been done? Bearings greased etc..

Temperature of the air, humidity all play a big part with fan use. Although I imagine it's not much cooler now in Indonesia than it was 2 months ago. Colder air is denser so requires more power moving it.

You also appear to be measuring the current at the main panel intake. Has there been something additional installed within this 2 month shutdown? OR something running from that panel that wasn't before.

 

[Lucien Nunes]

The current has increased by 52%, and if the supply is 400V and the voltage hasn't changed there is an extra 6.6 kVA going somewhere. If cause by bearing friction I think it would have made itself obvious after a run.

I would start by eliminating extra loads connected to the panel. Why are you not measuring at the motor terminals? Is this the same point that was measured when the plant was commissioned? Did you check all three voltages then and now? If all the voltages are correct and the three winding resistances are equal, I would be looking for what has been changed without you knowing. Blade angle, missing baffles etc.

 

[marconi]

Imam Purnono - WHY ARE YOU NOT WEARING ELECTRICIAN'S RUBBER GLOVES WHILE WORKING ON LIVE EQUIPMENT (AND EYE PROTECTION)?

 

[Imam purnono]

I would be checking the following

Phase voltages when running, a drop in voltage will cause an increase in amps

Check amps are the same across all phases

Check for any physical resistance to movement, I.e bearings etc.

Any significant changes to duct work could increase the power required to push the air through the system.

If it is controlled by a variable speed drive, has the set speed been changed?

thanks for the respect for that.
we faund the some rust at bearing and rotor, if we change the speed or enggel blade that will be lessthan air flow the system under normaly becouse cooling capacity droped..

 

[Imam purnono]

So has it been sat stationary for 2 months?

Any maintenance been done? Bearings greased etc..

Temperature of the air, humidity all play a big part with fan use. Although I imagine it's not much cooler now in Indonesia than it was 2 months ago. Colder air is denser so requires more power moving it.

You also appear to be measuring the current at the main panel intake. Has there been something additional installed within this 2 month shutdown? OR something running from that panel that wasn't before.

thanks for respect.
this only single panel for the 3 fan and power source directly from LVMDP,

but this area heavy rain a few month ago,
after recheck we faund some rust at the bearing and rotor,
greasing is inject type we can't open bearing seal.

The current has increased by 52%, and if the supply is 400V and the voltage hasn't changed there is an extra 6.6 kVA going somewhere. If cause by bearing friction I think it would have made itself obvious after a run.

I would start by eliminating extra loads connected to the panel. Why are you not measuring at the motor terminals? Is this the same point that was measured when the plant was commissioned? Did you check all three voltages then and now? If all the voltages are correct and the three winding resistances are equal, I would be looking for what has been changed without you knowing. Blade angle, missing baffles etc.

thanks,
yeah we faund some rust at the bearing and rotor,
this used a single panel for 3 fan and three voltage is normaly at 400v rate. we can't change blade be couse will be droped air flow and system unstabil.

 

[Imam purnono]

Imam Purnono - WHY ARE YOU NOT WEARING ELECTRICIAN'S RUBBER GLOVES WHILE WORKING ON LIVE EQUIPMENT (AND EYE PROTECTION)?

thanks,
yeah we evaluation for that. we would bearf the foreman
at the pic the system not run.
they on greasing.
we be soory for that

 

[dmxtothemax]

Maybe when you first measured the current the voltage was a little on the high side. now it's back down to normal or even on the low side.

 

[Marvo]

Did you check all the usual suspects like over tightened belts, over-greased bearings becoming hydraulically locked? Also the usual electrical suspects like phase voltages, phase current balance, operation of star delta starter if there is one?

As already mentioned, if it's an increase in the mechanical load that's caused a 50% increase in run current then something is going to get very hot and very quickly so it shouldn't be difficult to locate the problem?

*Edit* Don't worry about gloves and Hi-viz safety stuff, if you're in Asia or Africa you're exempt from having to wear them