Star Delta Motor Reading Amps in Star Veruss Amps in Delta
- #one
Star delta starter / motor problem.
Starter starts runs as should on demote with no motor connected. Getting 230v to e on all half dozen uvw 1s and uvw2. 415 u1 to v2 etc etc. But nothing 1 to 2s. As expected.
When motor continued up. (Single speed) it takes 3a in commencement on all . Drops into run fine but is taking 38a on all.
After v seconds it trips breaker.
Whatever ideas were to outset. As both out of stores every bit spares and checking they work just now stumped
- #2
Does the motor take a load continued to it?
Also check insulation resistance tests of the windings and continuity of windings.
- #3
Is this a recent problem on an existing motor or an outcome on a new install.
PS. No such matter equally a star/delta motor.
- #5
You need to analyze your opening mail it is somewhat confusing.
- #7
No load just on bench. Insulation is adequate. In runs fine in outset so presume windings are fine.
- #eight
Never said was a star delta motor. It'southward just ii items out of stores nosotros were checking that are ok.
- #ten
Was the timer previously prepare for that motor?
- #11
No non diddled information technology out only it runs fine when connected to dol started with links in motor 3 wire.
Information technology seems like losing a phase / low voltage loftier current???
- #12
Post a film of the motor and the nameplate.
And if you can the gubbins inside the starter
- #14
I would double check the wiring as the motor could be single phasing when it goes into delta ( aforementioned phase across both cease of the 1 winding)
- #sixteen
Star delta starter / motor problem.
Starter starts runs as should on demote with no motor connected. Getting 230v to east on all 6 uvw 1s and uvw2. 415 u1 to v2 etc etc. Simply null 1 to 2s. Equally expected.
When motor connected up. (Single speed) it takes 3a in outset on all . Drops into run fine just is taking 38a on all.
After five seconds it trips breaker.
When you say the Starter runs OK with no Motor continued, are you lot maxim the Starter operates as it should? and what practise yous mean past single speed?
If the Motor is starting, and connecting the Motor's winding in a Star configuration, but trips when it changes into a delta mode, then information technology sounds like you lot have either a faulty Motor, of you take it wired upwardly incorrectly.Any ideas were to start. As both out of stores as spares and checking they work but now stumped
- #17
Star delta starter / motor problem.
Starter starts runs as should on bench with no motor connected. Getting 230v to due east on all half dozen uvw 1s and uvw2. 415 u1 to v2 etc etc. But nothing 1 to 2s. As expected.
When motor continued up. (Single speed) it takes 3a in start on all . Drops into run fine only is taking 38a on all.
After v seconds it trips breaker.Whatever ideas were to start. As both out of stores as spares and checking they piece of work but now stumped
- #18
Why do you need to start it via star delta if you are able to start information technology DOL, how big is the motor and are the windings rated 415/690 or there abouts?
How are yous connecting the links when starting DOL I presume star as y'all say it starts fine when continued up to the star delta.
My bets on delta contactor in starter... although I can't sympathise from your original postal service if you've checked this?
- #19
Why do you need to start information technology via star delta if y'all are able to offset information technology DOL, how big is the motor and are the windings rated 415/690 or in that location abouts?
How are you connecting the links when starting DOL I assume star equally yous say it starts fine when continued upwards to the star delta.
My bets on delta contactor in starter... although I can't understand from your original postal service if you've checked this?
https://www.quora.com/Why-is-star-delta-starter-preferred-with-an-induction-motor
- #twenty
I sympathise this Pete but a motor that only draws 3A on start upwards doesn't need to be connected to a star delta starter to reduce starting current does it? without seeing the rating plate it's apparently small motor
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- #21
What does the data relate to on the starting procedure? there must be some information regarding this. I f it's a modest motor then we must ask the question why is star delta mentioned, what has happened to the rating plate?
- #23
If you were trying to start this motor via a star delta starter, there should be no links in at the motor concluding block, y'all would demand 6 half-dozen wires from the starter to the motor.
- #24
This is my point, the OP has gathered components off a shelf and assembled to exam either that the star delta starter is operational or that the motor is ok, simply non every motor tin can be continued to a star delta motor as yous know.
- #25
It really has to be the delta contactor if running fine in star, proves windings are ok, loosing a stage when delta contactor comes in.
- #26
h
Can the OP provide pictures of how he has connected the motor and the starter? this may help u.s.a. to get to the reply, after all it may be just a simple error in the concluding connections.
- #27
Please ignore my post #22 which has a gross wiring error in the diagram - can y'all spot information technology?
- #28
Could a set up of the windings exist connected to the aforementioned stage due east.one thousand. U1 and U2
Edit, Andy 1960 already mentioned this.
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- #29
Information technology shouldn't take 5 seconds to trip. though.
Delta contactor problem.
....and so again, if there are motor links, who knows? Someone playing most with something they shouldn't be springs to mind.
- #30
This argument is anomalous if you lot consider what you would measure with a voltmeter between the terminals of the Star and the Delta diagram in my mail #15.
eg for STAR - One would measure out 230V from each one to whatsoever 2 merely between any 2s would measure nada Volts.
eg for DELTA - Ane would measure 415V between any pair of 1s or whatsoever pair of 2s.
Betwixt U1 - W2, V1-U2 or W1-V2 one would measure cipher Volts.
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- #31
Have you checked delta contactor? Could exist a phase down
- #32
Y'all take removed the links when y'all continued the motor to the star delta contactor?
- #33
Hi yes we was testing separate items out of stores. So non knowing weather condition of either item.
Motor was original continued to dol and ran fine.
Obliviosly links were took out to connect to 6 wire star delta.
Thinking must be delta contactor problem.
But just curious at present every bit someone mentioned not all half-dozen wire motors will run on. Motor reminders confirm motor will run in either.
Anyway items been put back on shelf for another rainy twenty-four hour period tidy up.
Thank you for anybody'south help.
- #34
Three phase squirrel cage motors will have 6 ends at the concluding block, it's how they are connected that determines how they outset and run.
- #37
Using the Erroneous diagram , with K3 closed .
Are we looking at a course of symmetry forcing L1 and L3
into a tussle , and possible some circulating currents in the V1 & V2 contacts of K3 ?
Non Pretty !
(Spotted quite a few suspect /tweaked diagrams -Googling!)
- #38
As static zap said - The erroneous diagram in delta mode connects the U and W windings in parallel across L1 and L3 and shorts the V winding (and connects it to L2 only at i end but no current is drawn from L2). Acting every bit a three like winding transformer and Lenz's Law, the alternating magnetic fluxes around each winding must be equal in magnitude and together sum to zip. Thus the currents in each winding are the same in magnitude. The OP sort of told us this in his first mail service - 'taking 38A on all' - the currents being 120 electrical degrees apart).
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Source: https://www.electriciansforums.net/threads/3ph-star-delta-starter-motor-drawing-high-amps.123808/
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