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Kevin Levias

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I have a fire pump controller panel that im working on and i can't get the start button to hold the aux contact in. The stop button has burn marks on it. I can push the start button in and motor runs, when i release the button motor goes off. My question is could it be possible that the bad stop button could be telling the circuit to stop when the start button is released.
 
Usually in a typical control circuit the stop button is in series with the start button so an open stop button should keep the motor from starting.
 
That is quite simple to explain,

Many electricians are only exposed to certain aspects of the trade they may be one of the best in their field, be it electrical testing, fire alarm, controls, residential wiring, lighting, lighting protection systems, commercial wiring, hospitals, schools ect and if one seldom has the chance to work on specific items or be exposed them and even if they may have covered this in apprenticeship classes they have no need for this knowledge or exposure to it and that's the way it is.

Our trade is becoming very specialized and for some contractors this will be good.

Now I am not sure what your exact connection to the trade is but I am sure there is some aspect of the trade that you have a weak spot in..
 
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Jraef said:
I'd like to know how one gets to be an electrical contractor without the ability to troubleshoot this most basic of questions? :confused:
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Because not every qualified electrician has the same instinctive abilities to troubleshoot, or in the same way. Some of us can mentally picture circuitry, and some of us need to see a drawing. Some of us can read schematics, and some of us can only read ladder diagrams.

Not everyone who is perfectly capable of servicing existing equipment can determine the defecive component by noting the symptoms. Not everyone just knows that the stop button(s) is always in series with the rest of the control circuitry.

We all haven't had the same work experiences. There are excellent residential electricians who are lost on the industrial jobsite, and vice versa. There are people who know theory, but can't use tools.

Is there any aspect of electrical work you haven't mastered?
 
I like to kow how one gets to be a consultant and not know that ECs are generally extremely proficient at installing pipe and wire and may never do commissioning or service troubleshooting.

That was damn mean - what was your point?

carl
 
contractor

contractor

Not that I don't appreciate the "explainatory comments" made to jraef's statement and agree that, with the diversity involved in the trade, there are many electricians that are not multi-skilled, but, Kevin does list "electrical CONTRACTOR, as his occupation and with the testing plus experience required by most States, the question is a bit suprising form a contractor I must admit.
 
Brian, Larry Carl thank you.

To the others....

What purpose does slamming someone for asking a question serve?

This person knew enough to ask a question when they needed to.

I doubt they will ask another here and that is really to bad. :mad:
 
kevin need more info

what is motor voltage
what is control circuit voltage
PLC controlled

by the way, burnish the contacts on the stop button, power off, of course, and that should eliminate the stop, next check for a parallel circuit on the start button and trace those wires to their contacts......I run a shop for a manufacturer and have occassion to call electricians to help our staff elect when they can't solve a problem, i always explain the problem so they send the correct expert, solid state, hard wired, transformers or troubleshooter etc.
 
Ok Ok, Mea Culpa.
Actually, the point of my post was to question whether or not the OP was truly in the trade and not a DIY homeowner or an untrained mechanic who was attempting to do electrical work without proper consultation with a professional. One risk I see in fora such as this is that DIYers can ask questions as if they are pros and get tips, then go out and get themselves or others injured or killed because they knew only a small piece of the picture and assumed that was enough. I admit to being maybe a little too hyper vigilant, but for crying out loud, THIS GUY IS WORKING ON A FIRE PUMP CONTROLLER!.

And for those who asked, here is a brief CV. I went through my apprenticeship in the mid 1970's, worked to Journeyman status for an EC specializing in industrial systems, then worked in the electrical sales industry for many years after injuries from a car accident forced me off the jobsite. I finished my EE degree, then I started my own panel shop, sold it to an equipment manufacturer and worked for manufacturers for 15 years before going out on my own as a consultant.

When I went though my apprenticeship, we learned as much as possible about as many aspects of the trade as we could get exposed to. I was put on residential jobs, commercial lighting, industrial heavy construction and of course, control systems work. I chose control systems as something to specialize in because I saw that my aptitude for it was higher than many others, but I never knew anyone who couldn't figure out a basic 3 wire control hold-in circuit. I guess times have changed.
 
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The company I work for does about 12 million a year, all commercial/industrial, has 8 foremen, and I'm the only one around here who can wire a start-stop without a drawing. The other guys are not stupid, they're just not control guys. On the other hand, I absolutely detest running the big jobs that the other guys do so well at. We all have our specialties, and the most successful contractors put us where we are the happiest.

In answer to the original question, the latching contact would be my first guess. It's usually mounted on the side of the motor contactor. The problem could be electrical (contacts) or mechanical. It depends on the movement of the motor contactor to close its contacts, I've seen them mis-aligned, broken, etc. They can be difficult to replace, if it is bad, try to find another contact thats normally open.

Has it ever worked? This makes a huge difference in how I would troubleshoot it. If you can, post the brand, approximate age, and size of the starter. Someone around here will usually have some actual experience with it.
 
I have not worked on fire pumps but I must guess that it does not run very often. We literally have bugs that make themselves at home in seasonally operated equipment. Insect residue sometimes needs to be scraped off. A spritz of contact cleaner may not work.

A quirk of some installers is to but a limit or other control in series with the holding contact. Drives me nuts.

Have fun.
 
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