DOL starter / contactor

[Soulsurfer]

Hey all, I have a couple of jobs to look at which one is apparently not working right as is a single phase supply through a D.O.L starter / contactor for I think a borehole pump and another that is running a fresh air ventilation system and is now tripping out ! The thing is I've never needed to fit one or wire one so don't have any info on how to. The two jobs are for a friend and a friend of a friend so won't be charged as such.

Also apparently the pump one the girl has said the green start button doesn't do anything and only the stop button does stop the pump usually but if you let it go the pump runs again and doesn't stay off unless you twist it to lock it off ? sounds like the contactor is not wired right anyway ?

I have done contactors similar on A/C plant before which were 3 phase but wired for single phase supply where I had to link one input across to top of 2nd phase to balance the overload or it would trip. Is it likely that the ventilation one could be tripping due to a faulty overload or maybe faulty fan or failing fan ?

Anyone got any diagrams of the wiring for the contactor as direct on line or the coil connections etc.. or through a start and stop button system please?

Any help gratefully received and pints owed.

 

[westward10]

If one is tripping this normally due to excess current through the overload relay. The other may have a remote control if it is for a borehole pump and hence the green button may not serve a purpose.

 

[Pete999]

Hey all, I have a couple of jobs to look at which one is apparently not working right as is a single phase supply through a D.O.L starter / contactor for I think a borehole pump and another that is running a fresh air ventilation system and is now tripping out ! The thing is I've never needed to fit one or wire one so don't have any info on how to. The two jobs are for a friend and a friend of a friend so won't be charged as such.

Also apparently the pump one the girl has said the green start button doesn't do anything and only the stop button does stop the pump usually but if you let it go the pump runs again and doesn't stay off unless you twist it to lock it off ? sounds like the contactor is not wired right anyway ?

I have done contactors similar on A/C plant before which were 3 phase but wired for single phase supply where I had to link one input across to top of 2nd phase to balance the overload or it would trip. Is it likely that the ventilation one could be tripping due to a faulty overload or maybe faulty fan or failing fan ?

Anyone got any diagrams of the wiring for the contactor as direct on line or the coil connections etc.. or through a start and stop button system please?

Any help gratefully received and pints owed.

https://uk.images.search.yahoo.com/...t-001&hspart=avast&hsimp=yhs-001&guccounter=1

 

[Darkwood]

The bore pump probably works of a float switch which may have jammed in the 'call/run' position, this ultimately could lead to the demise of the pump if it runs dry especially if the seals are water cooled.
The issue with basic DOL control circuits comes about when the start option be it remote or not becomes permanently closed, the stop button then only serves its purpose as long as you keep it in operation and as soon as it is released it energises the circuit again.
The air circulation system could be one of many issues and is unlikely to be a faulty O/L - I would recommend you do a few simple steps like checking the fan is moving freely and bearings are not rough but maybe this one I would recommend they get someone experienced in if you cannot identify the issue as there are many problems that could effect loading.

 

[Marvo]

First thing is to go and investigate the entire control system, there's many ways each control system might be configured and many ways the DOL starter might be integrated and wired.

 

[MDJ]

you could disconnect the out going circuit and then try the starter to see if it is at fault or whether the external circuits are holding it off, not much to them really, usually the drawing is in the lid if you are unsure.

 

[mnbs 4x4]

Maybe a float switch

 

[Soulsurfer]

Thanks all, went to both of them today and found the previous plank had neglected to wire correctly or with marked colours / sleeving on cores too.

The pump is now activated via a danfoss pressure switch in the control circuit to tickle the coil, then the contactor pulls in and stays in running the pump which then also plays with a garden pop up sprinkler kit for the extensive greenery etc...

The overload was also set well below the flc and supply via a 50A mcb which was way over the top ! Only pulled 3-4 Amps all day long, all fitted and wired by the DNO !
2nd one was triggered by auxillary contact for start button to operate the coil and then ran a 3 phase beefy fan to supply air to the main bar & restaurant areas and then the cellar full of hot kegs and feed the chiller unit with fresh air, also very low on refrigerant so sorted that too. Now all cold again and was handed a cheeky pint of Fosters to check all was chilled sufficiently of course. Thanks everyone once again.