AC mains protection relay

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Todd0x1

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I have an application where a diesel genset will be powering a new construction home for a long period of time. The genset thats going on this job doesn't have a controller that will drop the load if the output is out of tolerance. I'm concerned the site manager won't keep an eye on fuel and will let the generator run dry. When that happens voltage and frequency goes haywire. Had another customer let this happen and blew out every occupancy sensor in a big building.

I'm looking for something that will monitor voltage and frequency and if its outside of a specified range will drop a contactor or trip a breaker. Any suggestions of such a product? Looking for the control module only not a complete solution.
 
What voltage / phase and how much do you want to spend (don’t just say as little as possible)?

Then what will you do with it, hold in a contactor, shunt trip a breaker?
 
Jraef said:
What voltage / phase and how much do you want to spend (don’t just say as little as possible)?

Then what will you do with it, hold in a contactor, shunt trip a breaker?
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Ideally I could use it for 120/240 1ph, 120/208Y or 277/480Y. This job is 120/240v 1ph. Hold contactor or trip a breaker. Was thinking up to mid $100s for the controller. Deepsea used to make one but they discontinued it. They do have one designed to drop grid tie generation if grid goes out, I need to see if that can be made to work. Or one of their autostart generator control modules.
 
Todd0x1 said:
I'm concerned the site manager won't keep an eye on fuel
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Isn't why fueling services and extra tanks exist? Have a service come out once a week or however long it takes to burn 2/3 of a tank. If you're going to buy the fuel anyway, do it on schedule, not only when somebody notices.

I assume this genset doesn't have a low-fuel shutdown in it's controller.
 
just saw your post.
frequency relay should be very doable with that budget.
 
zbang said:
Isn't why fueling services and extra tanks exist? Have a service come out once a week or however long it takes to burn 2/3 of a tank. If you're going to buy the fuel anyway, do it on schedule, not only when somebody notices.

I assume this genset doesn't have a low-fuel shutdown in it's controller.
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Yep, you'd think they would do that but they never do.

The genset that would go on this job doesn't have a fancy controller, it has the keyswitch to start and a manual idle/run switch. It's going to get a brain transplant at some point, I have had a deepsea controller and digital meters for it sitting here for months, haven't had time to design the new panel and get the sheetmetal done.
 
A motor phase monitor wired to open a contactor.
look at diversified atc for the phase monitor, pick out one with a low voltage and low frequency function, then a relay to go with
 
tom baker said:
A motor phase monitor wired to open a contactor.
look at diversified atc for the phase monitor, pick out one with a low voltage and low frequency function, then a relay to go with
Click to expand...
Yeah, I was thinking of the ATC Diversified relays too, but ones that look at frequency start above $300 and I had misinterpreted his price range. Years ago I had a project at a remote mine that was always powered by generators. The trained gorilla mine operators would get lazy at the end of the day and rather than open the generator breaker before shutdown, they would just hit the kill switch on the fuel supply and starve the engine. That resulted in the frequency dropping while still generating and that would scramble the brains on the soft starters we used, which was an unrecoverable fault resulting in having to replace the control boards. I put a Diversified phase monitor that looked at frequency shift on it and a shunt trip on the generator breaker, did the trick. As I recall though, that relay was over $300, and that was probably 20 years ago now.

I haven’t seen a single phase line monitor relay from them that looks at frequency however. But I wonder if voltage will drop too and maybe that would be good enough?
 
If you don’t need frequency the voltage only will be less money. But check with Radwell.com, they have used and open box for sale
 
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