2391-52 dol starter question

[Loki]

Hi,

I was hoping for some advice regarding testing a circuit with a dol start in it? As ive not yet work on one.

I was thinking for R1+R2 i could test L1 at the db to L1 on the dol input & then L1 output on dol to plugs then add them & r2 to get R1 + Would this be ok for the exam practical?

Was thinking for IR i could test L1 to L2/3 at the db & then L1 to L2/3 on the output side of the dol? Basically testing each side of the dol separately

Zs could be taken a plugs socket or could be calculated via Zs=Ze + (R1 + R2) method.

Hope that makes sense

Got my practical tomorrow & all my revision is making my brain turn to mush now + i dont like exams lol

Any advice greatly received

Thanks

Michael

 

[Bobster]

Link out the contactor, test as normal.

 

[Pete999]

Hi,

I was hoping for some advice regarding testing a circuit with a dol start in it? As ive not yet work on one.

View attachment 38242

I was thinking for R1+R2 i could test L1 at the db to L1 on the dol input & then L1 output on dol to plugs then add them & r2 to get R1 + Would this be ok for the exam practical?

Was thinking for IR i could test L1 to L2/3 at the db & then L1 to L2/3 on the output side of the dol? Basically testing each side of the dol separately

Zs could be taken a plugs socket or could be calculated via Zs=Ze + (R1 + R2) method.

Hope that makes sense

Got my practical tomorrow & all my revision is making my brain turn to mush now + i dont like exams lol

Any advice greatly received

Thanks

Michael

Personally I would carry out safe isolation of the Motor circuit, link the three phases at the contacter and carry out your tests.

 

[The Ghost]

When I did that (DOL starter test), I just did a continuity test and established there was no connection on L1 or to put it another way the L1 had a break, that was it.. I was asked to establish what the fault was and that was it. Oh and I was asked to look at the rating and statewhether it was adequate for the motor. The writing was really really small Oh and best of luck with the exam by the way!

 

[Loki]

How do i know if dol has thermal cut out?
Is that the blue bit by the dials?

Thanks for all the advice

Ok so for R1 +R2 im going to connect L1 & r2 together at the db, link across the L1 input & out put on the dol & plug the megger into the plug socket. Then repeat this for L2 L3 - recording the highest reading.

Regarding IR testing:
if testing at the db while the L1,L2 & L3 are connected to the input connector on the dol would this be ok or would it damage it? Also would it be ok testing on the dol out put side while L1, L2 & L3 are connected.
Worried about the thermal cut out being an issuse when IR.


Thanks again

 

[Loki]

Ok so after searching google it looks like the whole bottom bit that has the dials & blue bit incorporates the thermal cut out.
Left dial is amps setting next dial is manual or automatic reset & the blue bit is the manual reset button

 

[Bobster]

You're correct.

In regards to testing, IR and continuity will not damage that basic thermal overload module and should have no ill effect to results. Unless there is something wrong with it. (Be careful in future if you come across electronic ones).

Last AM2 examination place my apprentices went had them link out both the contactor and the overload. Although just bypassing the contactor is all that's needed.

Make sure the dial is set to the correct current rating.

 

[Loki]

Thanks rob for clarifying that for me.
As always everyones really helpful here

 

[Loki]

Just finished my 2391-52 practical tests, photo fault coding & written questions.
Well chuffed as i PASSED

 

[Pete999]

View attachment 38243
How do i know if dol has thermal cut out?
Is that the blue bit by the dials?

Thanks for all the advice

Ok so for R1 +R2 im going to connect L1 & r2 together at the db, link across the L1 input & out put on the dol & plug the megger into the plug socket. Then repeat this for L2 L3 - recording the highest reading.

Regarding IR testing:
if testing at the db while the L1,L2 & L3 are connected to the input connector on the dol would this be ok or would it damage it? Also would it be ok testing on the dol out put side while L1, L2 & L3 are connected.
Worried about the thermal cut out being an issuse when IR.


Thanks again

Just finished my 2391-52 practical tests, photo fault coding & written questions.
Well chuffed as i PASSED

Good Man

 

[Loki]

Thanks Pete.
Going to celebrate tonight lol

 

[Pete999]

Thanks Pete.
Going to celebrate tonight lol

Have a bottle for me

 

[Richard Burns]

Good work my man, all that trolling the forum has been worthwhile!!

Good achievement to pass that exam, it does mean you do understand what you are doing.
I am glad you passed.