| Author | Message | ||
| Iver (Mciv)
Registered Member Username: Mciv Post Number: 11 Registered: 11-2006 Posted From: 70.69.132.80 Rating: N/A |
My Kubota 9kw genset has two fans installed. One is a small squirrel cage fan for air circulation in the compartment and the other is a radiator cooling fan powered by a small 1/4 hp motor in the adjoining bay. These fans are wired through fuses directly to the genset. When the genset starts, the fans start within around 4 or 5 seconds. Is that bad for the genset to have a load on just after it starts? If so is there any way of delaying the fans for longer? Thanks, Iver | ||
| Jim Wilke (Jim Bob) (Pd41044039)
Registered Member Username: Pd41044039 Post Number: 205 Registered: 2-2001 Posted From: 12.8.169.106 Rating: |
While it would be a "big grunt" for the genset to start with nearly a full load, those loads are minor. It is very common to have cooling fans directly attached (through apppropriate fusing) to the genset. If you wanted to be fussy, you could run them through an inexpensive time delay relay or even a temp switch (use the switches they use on front wheel drive cars to operate the fan relay.) but you would be adding needless complexity & opportunity for failures. | ||
| quantum merlin (Quantum500)
Registered Member Username: Quantum500 Post Number: 25 Registered: 8-2007 Posted From: 71.33.238.169 Rating: N/A |
Actually a small load like that is good for the engine. Lets it warm up faster before you put full load on it. | ||
| Debbie and Joe Cannarozzi (Joe_camper)
Registered Member Username: Joe_camper Post Number: 59 Registered: 10-2006 Posted From: 71.239.202.82 Rating: N/A |
Cool down is more important. At least 5 min. with no load before shutdown This is how I set mine up. The small compartment fan should come on in pre-heat mode to exhaust any potential flammable gas before start-up. It is 12 volt. If you have a gas gen this is very important when you start sound proofing and sealing things down. The rad blower is 110 and comes on after you start generating. I suppose one could hook the 12 volt fan into a temp. sensor but I didn't and never overheated. We have a Kaboda 4cyl liquid cooled deisel in its own compartment seperate from the rad. So while its running the only thing drawing air into the compartment is the air cleaner/intake. | ||
| Iver (Mciv)
Registered Member Username: Mciv Post Number: 12 Registered: 11-2006 Posted From: 70.69.132.80 Rating: N/A |
Ok, I guess I'll leave it as it is. Thanks, Iver | ||
| Jim Wilke (Jim Bob) (Pd41044039)
Registered Member Username: Pd41044039 Post Number: 206 Registered: 2-2001 Posted From: 199.181.167.82 Rating: |
Debbie & Joe, If the "enclosure" is around both the engine AND the gen end, you need much more air than what is drawn into the enclosure by the air intake. The gen end requires many times the CFM than the engine burns to cool the windings. For example, an 8KW Northern Lights marine set needs 294cfm for the gen end, but the engine (3 cyl diesel much like the Kubota) needs 26.9cfm to run. A 12KW needs 378 for the gen end cooling & 40cfm for the engine to burn. In a boat, often these gensets are mounted in a closed sound enclosure which is vented to allow the gen end to draw it's air in through the back of the enclosure & exhaust the heated air through side vents. The rear (intake) of the gen end is sealed to the enclosure intake vent because air would rather circulate around in the enclosure rather than being exhausted. (The gen end will overheat if the air recirculates) If you get away with less ventilation, it is likely because the gen does not run continuously at full load. | ||
| quantum merlin (Quantum500)
Registered Member Username: Quantum500 Post Number: 28 Registered: 8-2007 Posted From: 70.57.21.17 Rating: N/A |
Joe Camper "Cool down is more important. At least 5 min. with no load before shutdown..." Your thinking of a turbo charged engine. A naturally aspirated engine will not suffer any damage unless it has a sever load on it just prior to shut down. Then you could boil over or actually burn the oil between the piston and sleeve unusual but possible. | ||
| Debbie and Joe Cannarozzi (Joe_camper)
Registered Member Username: Joe_camper Post Number: 61 Registered: 10-2006 Posted From: 71.239.202.82 Rating: N/A |
Its the generator end of the unit that needs cooling before shutdown Merlin, not the engine. | ||
| Richard Bowyer (Drivingmisslazy)
Registered Member Username: Drivingmisslazy Post Number: 1999 Registered: 1-2001 Posted From: 75.108.77.39 Rating: N/A |
A gen set running at heavy load will have a lot of heat built up in the engine and radiator and all the accessories. Typically 180 degrees. However, if the unit is suddenly shut down the temperature in the radiator and water will rise and so will the block temperature. That is the reason all gen set manufacturers recommend a cool down period when the unit is to be shut down. To get the coolant temperature down. In the hundreds or probably thousands of alternator/generator heads that I have purchased, I never saw a recommendation to cool one down before shutting it down. The insulation is typically Class F or H (250-350 degrees C ?)and that is way above the operating temperature of the engine. Richard (Message edited by drivingmisslazy on October 24, 2007) |
