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Generator
2

Generator

Generator

(OP)
Hello forum members,

I am actually working in the far Africa and is being confronted with a strange scenario. We have on site two Cat engines Model 700, rated 635 k VA 400 V 50 Hz.One set was manufactured in 2005 and the second one in 2006.They have got identical nameplates data.
The two sets are actually being operated seperately and there is a very urgent need to parallel the two to cope with additional demand. However, the people on site are claiming that the sets are not designed to be paralleled as a Cat represenative, I presume a sales person,told them two years ago. I am opinion that there should not be a problem to parallel them as they are identical sets.The support in the country is vey poor not to say inexistent.
Any comment.

Guardiano
 

RE: Generator

The governors may not be suitable for paralleling and load sharing. They may have to be replaced plus some other accessories may be required like cross current CTs, etc.

You need to find the CAT tech support for your area. Far Africa does not really narrow it down.

Rafiq Bulsara
http://www.srengineersct.com

RE: Generator

2
The model number you provided is not a correct CAT model number, so if you can get that I can provide some better info.

I've paralleled just about every CAT generator set ever built, including most of the Olympian line.  As noted above, the installed governor may not be suitable for paralleling, but there are several aftermmarket options, same with the voltage regulator.

I would recommend seeing if you can find a Woodward Governor Company rep for your area, Woodward has several solutions for paralleling gensets that are reasonable cost to retrofit.  There are other possible providers, but I know Woodward has multiple options for CAT units.

Hope that helps.

RE: Generator

(OP)
Thanks Messers Raffick and Catserveng.
You are right M. Catserveng, the model nimber I gave is the one on the generator. The model number of the engine is C-18,the Ar No is 241-2422 and the DEM No is 241-2422. Both engines are identical.
Thanks again for your help.

Guardiano

RE: Generator

We had a large motor that one generator could not start. We had to parallel two sets of different size, one with an electronic governor and one with a hydraulic governor. We did have to wait until the oil warmed up in the governor (about 15 minutes) before we could start the engine.
One thing that will prevent paralleling is governors set on isochronous mode. This is usually switchable. Run them both in droop mode and look into cross current compensation.

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

RE: Generator

The C-18 is an electronically controlled engine, so to add droop you will need a technician with ET (the CAT computor based service tool) to make the change to the ECM.

They can be manually paralleled in droop, but if these are new units, they were likely shipped with the CAT EMCP3 control panel, and adjusting the speed settings for load sharing doesn't work too well sometimes, so you could have problems "fine tuning" the load sharing.

These units likely did not ship with generator droop (or sometimes called cross current) CT's.  So to properly parallel and share VAR's you will need to add a droop CT on each generator and adjust droop to 3-5% of rated voltage.  Same issue with voltage control from the EMCP3, again "fine tuning" sometimes is difficult, but in droop mode it will likely drift a bit anyway.

I did a project with four C-18's about two years ago, they came from factory with generator droop CT's, we added Woodward GCP-30 controls for paralleling, load and VAR share.  Worked pretty good.

Sometimes units going into Africa, the Middle East and Europe are packaged by FG Wilson in Ireland, and have Woodward controls installed instead of the stock CAT EMCP3 panel.  If that is the case you may be able to parallel with those controls, but would need to verify part numbers and setup configuration.

Hope that helps.

RE: Generator

IMHO should not be any problem to parallel the sets. To do it safely you need to install an Auto Synch, Load Share & Start-Stop On Load Demand Control Panel.
You need to order the panel to a reliable manufacturer who will test and commission it until your acceptance.
 

RE: Generator

Ironically, there are now some "small generator" (1000 and below) paralleling add-on's that you can buy off the shelf in Home Depot and Lowes to allow starting welders and air compressor, etc.

But the bigger units aren't quite available at the big box stores.

RE: Generator

I haven't seen what is offered at the big box stores, but I would bet it's the paralleling cable to connect a couple of the small inverter based sets which run the engine at variable rpm to meet the demand.

RE: Generator

(OP)
Thanks Catseveng for the expert advice. We finally got hold of a Cat Rep and he is expected on site in a few days.

Guardiano

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