any expert here on pump system and electrical?

[ykhuser]

i have 2 huge submersible pumps.
when water is full, the pump will operates.
the pump are quite new (less than 3 mth old )
it ramp up slowly via VSD to 50hz
when there is no more water , the pump ramp down slowly via vsd

prob:
the 2 pump very often will have overload trip
when it ramp down..there will be high amp.

different engineers have concluded that there is no prob with the motor (they mega it )
there is no prob with the cable.
the water suction to the pump has no obstruction.

any experts know why?

 

[Suriyothai]

I want to help. Knowledge getting rusty. What is VSD?

 

[chonburifc]

I want to help too. But need $$$. Now only think whisky. No $$$ no talk. U pichar lobang liao. in Oil and Gas biz dio boh?

 

[Suriyothai]

VSD must be Variable Speed Drive.

Maybe have a look at the parameters setting of the VSD. Parameters related to current. Setting maybe be higher than the overload relay which often trip. Is there Overload relay connected after the VSD before the motor pump?

 

[chonburifc]

VSD must be Variable Speed Drive.

Maybe have a look at the parameters setting of the VSD. Parameters related to current. Setting maybe be higher than the overload relay which often trip. Is there Overload relay connected after the VSD before the motor pump?

respect respect.

 

[ykhuser]

VSD must be Variable Speed Drive.

Maybe have a look at the parameters setting of the VSD. Parameters related to current. Setting maybe be higher than the overload relay which often trip. Is there Overload relay connected after the VSD before the motor pump?

could it be some current harmonic?
you mean setting for current should be lower than the rating of the overload relay?
should have some overload Contactor in the start / stop panel.

maybe you can pm me?

 

[looneytan]

sinkapoor got no ponding, you use pump for what!

 

[chonburifc]

sinkapoor got no ponding, you use pump for what!

Nabez lah. Technical question lah. Me also want to learn a little bit lah. But the screw thing quite impressive leh. Only 10 dollar nia. If me. I smash the whole thing liao. Botak! Just observe and shut your mouth, me also learning hor.

 

[MenghidupKehadapan]

Is the system on a RCD circuit? If so, it is a common problem I encounter in the course of my work here in Perth.

As VSDs rely on manipulating sine waves and DC to produce the various effects in the motor, the current diverted back to either phase will cause imbalance to the system which may then trip the RCD.

My recommendation to clients is always either hardwire the motors directly to the DB, where the RCD (100mA) can be set at a higher rating, or use an isolating transformer (415V/415V) with the 415V supply from the board and the secondary output to feed the VSDs, that way, any current imbalance will not be fed back to the primary side of the transformer and therefore no trip will occur.

If this is for your workplace, then I will further suggest you do a mega test again after re-installation

i have 2 huge submersible pumps.
when water is full, the pump will operates.
the pump are quite new (less than 3 mth old )
it ramp up slowly via VSD to 50hz
when there is no more water , the pump ramp down slowly via vsd

prob:
the 2 pump very often will have overload trip
when it ramp down..there will be high amp.

different engineers have concluded that there is no prob with the motor (they mega it )
there is no prob with the cable.
the water suction to the pump has no obstruction.

any experts know why?

 

[Suriyothai]

could it be some current harmonic?
you mean setting for current should be lower than the rating of the overload relay?
should have some overload Contactor in the start / stop panel.

maybe you can pm me?

Yes. Current setting for the VSD should be lower than the separate overload relay settings. When u say tripped, which one trip? Overload relay current or VSD trip? Is your contactor with overload before or after the VSD? If remember correctly, I use to design such circuitry without overload relay. The parameter setting within the VSD would take care of this over current thingy.

 

[ykhuser]

Nabez lah. Technical question lah. Me also want to learn a little bit lah. But the screw thing quite impressive leh. Only 10 dollar nia. If me. I smash the whole thing liao. Botak! Just observe and shut your mouth, me also learning hor.

the screw thing lucky it work within 3 days.
if not it take 3 weeks to order and reach site..
by then will be big hoo haa

 

[ykhuser]

Yes. Current setting for the VSD should be lower than the separate overload relay settings. When u say tripped, which one trip? Overload relay current or VSD trip? Is your contactor with overload before or after the VSD? If remember correctly, I use to design such circuitry without overload relay. The parameter setting within the VSD would take care of this over current thingy.

yup.is the VSD trip.it got some error code which no body know how to interpreted.
to reset the trip, we power off the main incoming.which also cut off the VSD power...and power back on again .

btw..why does ramping DOWN motor speed to complete halt will also draw high amp?

 

[ykhuser]

sinkapoor got no ponding, you use pump for what!

to drain off rain water when there is a heavy downpour.

 

[summervale]

According to our great leaders, ponding do happened once in every 50 years. So, no use keeping the pump as it will be obsolete by then.

Happy Holidays!

sinkapoor got no ponding, you use pump for what!

 

[Getloud]

yup.is the VSD trip.it got some error code which no body know how to interpreted.
to reset the trip, we power off the main incoming.which also cut off the VSD power...and power back on again .

btw..why does ramping DOWN motor speed to complete halt will also draw high amp?

Get the manufacturer manual go to troubleshooting chapter and look at the error code.

 

[Suriyothai]

Get the manufacturer manual go to troubleshooting chapter and look at the error code.

Correct, since the trip comes from the VSD, try understand what the error code says first. Afterwhich relevant questions can be ask, else it would be just guessing.

 

[Suriyothai]

"upz. upz. bro u in oil and gas , dio boh?"

Pai say pai say, seldom post here and still very new to some of these features. I believe some bros here up some points for me. Thanks whoever you are. And no I am not in oil and gas. Was formerly involved in electrical engineering for machineries and dealt a lot in control panel design and uses a lot of VSDs.

 

[ykhuser]

"upz. upz. bro u in oil and gas , dio boh?"

Pai say pai say, seldom post here and still very new to some of these features. I believe some bros here up some points for me. Thanks whoever you are. And no I am not in oil and gas. Was formerly involved in electrical engineering for machineries and dealt a lot in control panel design and uses a lot of VSDs.

previously the oem checked and say the error codes say the vsd over heated.he suggest to put extraction fan in the control panel.
i not sure if he is lying..
what is your take?

 

[Suriyothai]

I dun think the VSD OEM is lying, though many engineers lies.... VSD do generate a lot of heat during operation. During design stages, we tends to give ample spaces, left right, top and bottom to the VSD placement in order for their generated heat to escape and dissipate. Exhaust fans are commonly part of the control panel feature to help extract these generated heat.

Hope this helps...