pump keeps going off

[speed]

hi
i have a problem that every 5 or 10 minutes my pump stops

i have a ABB B9-30-10 Contactor
and a ABB T25 THERMAL OVERLOAD RELAY

when this happends all electricity is still working
but the ABB B9-30-10 Contactor switches off
i assume this is because of the ABB T25 THERMAL OVERLOAD RELAY?

there is a volt and some other things you can turn on front of the ABB T25 THERMAL OVERLOAD RELAY, and then it will work for another 5 or 10 minutes

i connected the pump directly to the 220volt, and thats been running perfect

so what could be the problem?
could the ABB T25 THERMAL OVERLOAD be bad?

any input is welcome

thank you

 

[Ohm_Boy]

It sounds like you have a three-phase motor. I suspect that there is more complexity in the control system than we could diagnose without more information.
Is there a schematic diagram of the control system?

 

[Ohm_Boy]

Thermal overload relays work by detecting overcurrent situations with the motor, and they open a set of contacts in the control circuit. It usually takes a few moments to trip with just a light overload, sooner for a larger overload. The adjustments on the front determine the trip point. They can go bad, but it is FAR more common to have a problem with either the motor or the supply voltage. It is difficult to troubleshoot without an electrical meter.
Make sure that there is not some obstruction in the pump, and check all three fuses feeding the motor - one of them may be blown.

 

[speed]

hi
this is the pump

no schematic, but this is the electric box

check all three fuses feeding the motor
where are they located?

ps. if i connect the pump directly to the same power supply, its working fine, for the last years
still could be the pump?

i have a electrical meter what and where i should meassure?

 

[Ohm_Boy]

Awesome. It's been a while since I've worked on European controls.
You do not have a three-phase system, but you do have a three-phase motor control contactor and overload relay. This may not make much sense to you because I tend to ramble through boring details...

Essentially, this is handled by "wrapping around" one leg of the control to the third leg contacts. Those overload units require balanced power - all three legs must have the same current through them, or it will trip. In fact, they use a lever mechanism inside for mechanical advantage to trip faster for phase imbalance than for normal overload.

[blabby description - feel free to ignore] In other words, one power leg (L1) goes into one terminal at the top of the contactor, out the bottom to the overload unit, through the overload and out the T1 terminal to one power terminal of the motor. The second leg (L2) goes to the second terminal at the top of the contactor, out the bottom of the overload unit (T2), and then is connected back around to the top of the contactor at the L3 terminal, through the overload unit, out the T3 terminal, and connects to the second motor terminal.[/blabby description]

I'm going to have to run out for a bit, but I'll try to sketch you something up tonight or perhaps tomorrow, if you can hold out that long.

 

[speed]

right
i think i am staring to understand it a little now

so basicly it could be theses 3 things

pump
supply voltage
overload relay

since you can adjust this overload relay, i think i should start measure and adjust and try to get 3 even currents?

yes a sketch would be awesome
not in a hurry

thanks

 

[Ohm_Boy]

You don't actually adjust the current. It is a feature of how much work the motor is doing. The overload relay only SENSES the current, and if it reaches a certain level (the 'trip' point), then it opens contacts for terminals 95 & 96 (used to open the control voltage to the contactor), and closes contacts for terminals 97 & 98 (used to turn on a light, or horn, or some other signaling function). It does not ever interrupt the current flow to the motor, that is done by the contactor.

The adjustment on the overload is to set the actual trip point for the motor current. I think that unit is adjustable between 1.3 and 1.8 amps. It should be set to match the nameplate current rating on the motor.
I don't have a lot of familiarity with ABB's product catalog, so I'm not sure about the other adjustments, but I think the center 'knob' is an auto/manual reset control, and the right-hand blue thing should be the reset.

 

[speed]

i have a machine that measures the voltage and wattage used by a appliance connected to it
with this i should be able to see if the pump is good or not?
so then the pump could be ruled out i guess, or we found the problem?

more or less similar to this

 

[speed]

ok
with this energy meter i get:

volt 218-222
amp 3.38-3.42
watt 530-560

so does this rule out the pump?


also i have a multimeter ready
where i should look for what?
voltage? wattage? amperage? or all?

 

[speed]

ok after measuring the voltage i get 225-235 volt and even a spike of 239 volt
doesnt sound right i think?
what could cause this?

 

[speed]

update
i measured the volt coming in the house
and its also around 230 volts

then i went to measure some in the pump house
but after a carefull insection i found
i think its t2 thats going back to l3 is burned

so what does this mean?

 

[Bama Rambler]

That looks like the problem.

 

[speed]

ok the cable is fused inside the relay

i cannot find any ABB T25 THERMAL OVERLOAD RELAY in my country
any other THERMAL OVERLOAD RELAY will do?
or does it need to be this specific model ABB T25? which i only can find in the usa

 

[speed]

i am looking now, but i cannot find if it is allowed to put eflay links?

so many different Overload Relays
any of these will do?

Eaton Cutler-HammerC316 FNA3M Thermal Overload Relay A 4.5A - 6.5A
IMO U12/16A 11 Thermal Overload Relay 10amp I130
Cutler-Hammer Eaton C316 FNA3G 1.3 - 1.8A F.L.C Series A2 Thermal Overload

 

[Bama Rambler]

Any o/l relay will work as long as it's rated for the motor current. FLA (full load amps) on your motor is 6.2 amps so C316-FNA3M should work but one with the FLA in the middle or lower end of the range would be better if you can find one.

 

[speed]

FLA in the middle or lower end of the range you mean something like around 3 amps?

maybe better i found the ABB T25 DU in europe
but i see there are many different ones

T25DU 2,4
T25DU 1,4
T25DU 1,80
T25DU 3,1
T25DU 0,40
T25DU 0,25
T25DU 0,16

if i understand right i would need the 3.1?

this i have now

 

[speed]

so how much amp relay i want ideally for my 6.2amps motor?

would any of these for example work (chinese)

 

[Ohm_Boy]

Am I correct that your overload is (was) adjustable from 1.3 to 1.8 amps? And your motor is rated 6.2 amps? I think I see a problem there.

You will need an overload which can be set to 6.2 amps. I believe ABB's model range has a 4.5 - 6.5 amp model T25DU6.5 They may have replaced the T25DU line with the TA25DU. See if you can find a TA25DU6.5 or it might be labeled TA25DU6.5-20.

TECHNICALLY, any IEC overload relay in that contactor frame size and current range COULD work, so Telemechanique, Eaton, Moeller, etc. units MIGHT be used. *BUT*, these things are made with some sort of hook/tab/etc. to help physically attach it to the contactor, in addition to the three power stabs. This helps make it more of a solid single unit once assembled. The hook/tab/etc. MAY be different from manufacturer to manufacturer, so watch for that.

 

[speed]

yes motor 6.2 amps
but not 1.3 to 1.8 amps? it was 4.5 - 6.5 amp inside
so why did it blow?

anyway i found 1 ABB TA25 DU, waiting for shipping quote for him
just noticed its a used one
normally they are probe to breaking?

and otherwise i guess i will go for this one or something similar
Cutler-Hammer Eaton C316 FNA3M 4.5 - 6.5A F.L.C Series A2 Thermal Overload Relay

 

[Bama Rambler]

Your FLA is 6.2 so any O/L with a setting that covers that range will work.

it was 4.5 - 6.5 amp inside

This would be a TA25DU6.5. I'm bothered by the fact that the dial is set to "A' which would be 4.5 amps. I think you've found your problem but I'd try and get the setting closer to FLA of the motor on the new one.