Generator or Backup Options?

[allsyntax]

I have what could be a quite basic question for you electrical guru's. I have some equipment that is in a rural area. During the storm seasons, intermittent power outages can occur. This causes the equipment to shut down, and must be manually turned back on.

My first thought was to get a generator to provide as a backup. But if I had some form of a battery backup, this may suffice since the outages are brief (a few seconds?). The power requirements are 45.6 amps.

What would guys recommend from your expertise?

 

[ScottyUK]

rugged,

ACBs? For a 45 amp load? You must have money to burn.



----------------------------------

If we learn from our mistakes I'm getting a great education!

 

[itsmoked]

If you want real reliability then add a test load and have the PLC run it once a week and leave a green light ON if the load was run successfully or a red light if not. Then who ever visits just checks the light. If it's red then investigate. You can also have to PLC flash the red light if the generator needs it's annual service.

The PLC can have the generator run the test load for 15 minutes a week so you dry out all the accumulated moisture from the engine oil etc.

Keith Cress
kcress -

http://www.flaminsystems.com

 

[allsyntax]

That sounds like a good idea itsmoked.

Anyone have any recommendations for type of PLC I would need? Would it be one like this:

http://web6.automationdirect.com/ad...C_Hardware/DirectLogic_05/PLC_Units/D0-05DR-D

 

[jme1976]

Try Deepsea electronics...

http://www.deepseaplc.com/

 

[itsmoked]

Those would work. I'd grab for one of these or any of the identically differently named devices made by others.

http://www.factorymation.com/s.nl/sc.2/category.22/.f

Keith Cress
kcress -

http://www.flaminsystems.com

 

[allsyntax]

Ok thanks, great links guys I will be looking into those.

Im trying to go over the generator requirements based on the data I have.

So if watts = (amps * volts) * load factor

Then, I would be at (45.6 * 240) * .8 = 8.755 kW

Is this correct? Would that for general operating? And I would need something in the range of 15-18 kW due to motor starting power demand? Can you guys educate me in this area?

 

[itsmoked]

Yes motors require much more to start successfully then just their running load wattage.

As for your 45.6A that really means nothing in the context of how you've been using it. Have not a clue...

Is this three phase power or single phase power? Where did you get this number?

When it comes to motors, you are interested more in the HP than the current when sizing generators. You back into the current from the horsepower requirements.

Keith Cress
kcress -

http://www.flaminsystems.com

 

[rbulsara]

allsyntax:

Joining the party late, but you need to define the problem and the goal first. The original post suggests "This causes the equipment to shut down, and must be manually turned back on."

Is the issue shut down of equipment or just manually starting back or both?

If just manual re-start is the problem, generator will not help as the equipment still will shut down and needs to be started up, either automatcially or manually.

If only a auto-start will solve the concern than all you need is auto restarting control circuit, which is pretty easy.

If even having momentary shutdown is an issue and you do not want to go down at all than you wil need a UPS. If the outages are longer than a few minutes than you may need both the UPS and generator. YOu need to define your issue further and apply the appropriate solution. Hire some experienced professional help.

 

[itsmoked]

Wasn't this all covered already?

Keith Cress
kcress -

http://www.flaminsystems.com

 

[allsyntax]

Yes, we have covered all of that.

In my last post I just wanted to see if I could calculate on my own how many watts would be required to operate the equipment to size the generator.

It's single phase electric. One of our operators gave me the 45.6 number. He may have totaled the # from the badge of each motor, I'll have to check back with him to see exactly.

Also FYI I will not be installing this myself. I'm just researching what options were available and I thought who better to ask than electrical engineers, no harm no foul

 

[waross]

The major manufacturers offer enclosed packaged sets and automatic transfer switches. The packages are enclosed, weather proof, and quiet. The best pricing that I have seen for automatic transfer switches is when they are bought as part of a generator package. F.G. Wilson,or Olympian (CAT owned) Onan, and others.

Bill
--------------------
"Why not the best?"
Jimmy Carter

 

[davidbeach]

Most of the manufacturers also offer sizing software that you can use or that they will use for you. Put in your loads, your voltage dip criteria, the starting sequence, and out comes a generator size that will meet those criteria.

 

[allsyntax]

Ok thanks. I will be looking into that and let everyone know what was ultimately decided.

 

[waross]

A tip on comparing generator offerings from various vendors.
18 kW to 24 kW is about the maximum size of single phase generators. Above that size three phase alternators are reconnected and re-rated for single phase.
You may be faced with sales proposals for both single phase machines and re-connected three phase machines.
For example, a three phase 30 KVA, 24 kW, 0.8 PF alternator will be reconnected as a single phase, 20 KVA, 20 kW, unity PF machine. The engine will still be capable of producing 24 kW. although the alternator will be overloaded.
A single phase 20 KVA machine will have an engine suitable for 16 kW or 20 kW depending on the power factor rating.
The re-connected three phase machine will start motors much better than the single phase machine. The short overload on the alternator during motor starting will not be an issue. The re-connected three phase machine will be well worth the extra money that it will probably cost. The engine will last much longer also.

Bill
--------------------
"Why not the best?"
Jimmy Carter

 

[itsmoked]

Nice tid bit there Bill.. Thanks for the lesson.

Keith Cress
kcress -

http://www.flaminsystems.com

 

[roydm]

This sounsd like a perfect application for fuel cell technology. The company I work for has done several pilot plant studies using different types of fuel cells, not just conventional Hydrogen powered. e.g. Liquid/Liquid for power station Black Start and Submarine.
Since you have natural gas available a Hydrogen/Air fuel cell would be practical.
Regards
Roy

 

[LionelHutz]

I was just reading this and thinking what Roy has posted. Some sort of continuous operated generator could be practical and forget using the hydro company supplied power completely. The last time I was in an oil/gas area I saw a few generators that were running fuel cells or some other technology.

 

[allsyntax]

Thats very interesting. A lot of helpful information provided by everyone. I will have to look into this option as well. I realize this thread has become quite lengthy (which is a good thing), so thank you for those who continue to take the time to read through the discussions and provide input based on your experiences.