Need help with 21kw genset

[Frank S]

New breaker solved it. Just gotta figure out how to keep gen cool when 116 degrees in summer. Gen running hot, 230 and up.

I noticed from the first picture you posted that it looks like it is in an enclosure  the radiator at one end with an aux fan at the other end
 Is the box insulated or plain
 Are you running it with doors on or removed
Is it mounted on a trailer or sitting flat on the ground
IS it sitting in direct sunlight or shaded
If the box is insulated with sound suppressing materials and you are running with doors closed try washing the interior including the radiator core fins check the aux fan to see that it is running at full speed.
If sitting in direct sunlight try shading at least the area where  the aux fan is, if it is siting flat on the ground the incoming air could be heated by the surface in sunlight
 if running with doors open or removed close them this helps to concentrate the air flow through the radiator
 make sure you ave a good coolant mix antifreeze to water ratio. if it has been more than 3 years since it has been changed flush the system several times then refill
 open the thermostat  housing drop the thermostat in a pan of water then heat it until it opens. see that it opens fully at the correct temp.
 refill the system and it does not have a water filter add the specified amount of Nal-cool unless the antifreeze coolant states that its rust inhibitors are not compatible
 When all else fails it could be that some equipment is simply not engineered for operating in 116f conditions 

[GameRV]

Generator is in an enclosure (side storage of RV). We disconnected the 12v fan as it was drawing too many amps and thus not allowing the gen to turn over. The RV was a book mobile in Denver and they did everything to keep that compartment warm. We are reverse engineering that for hot Vegas summers of 116 degrees and above. When there is no load, the thermostat opens and closes at about 185 degrees like it is rated to do. However, once we turn on ac's, xbox's and tv's, the temperature rises to 230 and thus stat stays open. We are looking to remove that 12v fan and mount it in the other side thus forcing air right at the radiator. We have removed the insulation and back panel to let air flow. The door is closed and vented so no direct sunlight but I bet the reflective heat from the black street asphalt contributes to gen temp.

[Frank S]

Generator is in an enclosure (side storage of RV). We disconnected the 12v fan as it was drawing too many amps and thus not allowing the gen to turn over. The RV was a book mobile in Denver and they did everything to keep that compartment warm. We are reverse engineering that for hot Vegas summers of 116 degrees and above. When there is no load, the thermostat opens and closes at about 185 degrees like it is rated to do. However, once we turn on ac's, xbox's and tv's, the temperature rises to 230 and thus stat stays open. We are looking to remove that 12v fan and mount it in the other side thus forcing air right at the radiator. We have removed the insulation and back panel to let air flow. The door is closed and vented so no direct sunlight but I bet the reflective heat from the black street asphalt contributes to gen temp.

[We disconnected the 12v fan as it was drawing too many amps and thus not allowing the gen to turn over.] the fan should not have even been on unless the gen was at op temp
the amp draw should not be that great to prevent starting but again should not be running unless the gen is running at temp

[We are looking to remove that 12v fan and mount it in the other side thus forcing air right at the radiator] This works only if the engine fan draws air through the radiator like a car engine. IF this is the case then the fan might help just like an artillery fan on a suv sitting stopped in traffic  trying to force additional air across the AC condenser otherwise if the 12v fan does not force more air than the engine fan can pull it will act as a restriction
 I suspect the radiant heat from the asphalt may play a huge factor in your case.
  I know a lot of RV'ers who will flat out refuse to park their units in the middle of a large parking lot, when ever possible they will back their RV's until the back is on the grass for the reasons you are experiencing.
 
 Removing insulation unless it is blocking air flow probably will not help and will only serve to allow noise production to be transmitted at higher Db's
 The inlet area feeding the radiator should be larger than the core area for free air the same goes for the outlet. When at rt angles to either then even larger areas are better.

[equiluxe]

If the radiator fan pulls air over the radiator you would be better leaving the electric fan where it is but make sure that it is drawing hot air out of the enclosure and not blowing in, but it may well be that the radiator fan blows, not sucks over the radiator in this case the electric fan needs to blow into the enclosure. It is quite likely that the radiator fan blows out and the enclosure is made to duct the air across the whole unit to help cool it, leaving the doors open will defeat this feature  I have seen units blown up this way as the sides were left open and the one fan was used to pull air through the generator as well as the engine.

[WindriderNM]

You could try to add another radiator and fan somewhere outside the gen box

[rearden]

The electric fan should only turn on once the temp reaches a set level and be cut out of the starting circuit, so it should never interfere with the starting of the generator.

You may be able to add an engine oil cooler.  They are not that expensive, but provide an additional method of removing heat from the engine.

As was mentioned before, if you have poor power factor then your engine will be working harder than you think causing it to run hotter.  I am not the best one to tell you how to do this correctly but you should be able to add a few power factor correcting caps to your loads to improve the power factor (and probably lower the THD and clean up the power in the process).  If you have to replace any of the flourescent ballasts or power supplies get ones with a PF as close to 1 as possible.

You mentioned before that you have a 63 amp spike when the ac turned on.  If you look at the identification plate on your ac units they should give you LRA (Locked Rotor Amps) and RLA.  LRA is the max starting current you need when the AC turns on, especially when there is pressure on the system.  Generators are often sized based on LRA not running amps, which are much lower.

Some of the posters mentioned various ways to lower the pressure in the ac system when the AC unit turns on (by waiting) or to limit the number of ACs which can be turned on at a time.  These are ways to reduce the sum of the currents while starting.  Additionally there are methods which can be used to lower the LRA of your system.  Your AC guy should be able tell you about them.  They are used to reduce the "light dim" when a compressor starts up.  This light dim is caused by the temporary but huge draw at start up.  These "easy start" kits may or may not be applicable to the motors in your system, but they would be worth checking out.

rearden

[XeonPony]

1 year to the date, not the worst necro thread I've seen befor!

[GameRV]

Just to see if anyone still following. New summer and yeah it's hot here in Vegas, 100 degrees all week. Problem is just that I can't get the engine cool. Unsure if adding another radiator / fan in another location will work but I am open to all suggestions. There are craigslist postings for military grade 30kw generators on a trailer......how do they keep that cool? It's enclosed like mine. Just so frustrating failing to keep this gen / engine cool. Hope yall can help.

[dnix71]

GameRV you need an external oil cooler. Antifreeze cools the top half of the engine, the oil cools the bottom half. Good external oil coolers are not cheap, though. You might consider making your own. A small electric pump mounted next to the oil pan could circulate oil from an external oil radiator with a small fan on it. Tap the sender fitting for feed and use the pump to insure constant flow and return. Mount the cooler below the oil pan so the oil level in the pan will not change with the unit off. If you mount above, the oil will drain back and may overflow the pan.

http://www.junkyardturbos.com/Turbocharger-Oiling-Systems.php Same priciple as installing a scavenger pump for an aftermarket turbo. Except in this case you run the oil from the engine through an external aftermarket transmission oil cooler then back to the engine.  http://www.summitracing.com/parts/bmm-70297 On this one the fan comes with a thermostat.

http://www.ebay.com/itm/New-12v-Differential-Transmission-Oil-Cooler-Gear-Pump-Unlike-Mocal-and-Tilton-/280782675244 A Mocal pump here. $150.

[GameRV]

Ok, before we get heat under control, new wrinkle. Gen runs but no power. I am going to work with the mechanic today with the electric drill method in an attempt to polarize the field. If that doesn't work I am guessing we troubleshoot the AVR to determine if its bad. Thoughts?

[GameRV]

Corded drill worked! What an awesome concept.