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| Subject - 3-phase 60 kva diesel Generator | |
| Garr |
Would like to use on my house on single phase. What would be a good way of doing this without alot of money. I figure a transformer would give me better operations and less power loss. Michael |
| wareagle | what is the voltage? |
| lctrc789 | Are you saying you have a 3 phase 60 KVA generator and you want to use it for single phase for your home? Does it have a switch for 120/208 WYE single phase if not then you could use a transformer. Most localitites do require you to use a transfer switch at least but I guess we need a little bit more input for sure to answer what you are asking exactly. |
| Garr | The voltage is 208 3-phase, I figure that I could just use two of the phases thru a transfer switch. Would you agree. |
| wareagle | You can but most residential load is 120 or 240 volt. How will you handle the different voltage? Also A generator that size is going to use a lot of fuel. Will it be efficient to use such a large generator? |
| frenchelectrician | garr: i dont know if you did add up the load what you plan to run on the generator if not better do it because you will get the idea how much load you are planning to run at once . i install quite few of standby generators for homes and most use 15-20 KW range and work out pretty good for that size but for larger home you may have to go bigger unit but really you should get all the figures what you need to run on stand by power source then if you will run everything from the house or not ?? 60 Kw is pretty big unit btw and if run light load all the time it will be more harder on diesel engine than smaller diesel or gas generator size because if you run light load on the generator all the time you will get wet stacking and few other probems show up better off to load it up about 50 to 75 % of generator size to keep engine running good if more question just drop a line here Merci , Marc |
| CGET | quote: Marc, that is almost correct. Wet stacking is a problem inherent to almost every diesel engine. Most diesel gensets that produce 60 Hz power run at 1800 RPM. What causes wet stacking is not RPM or load. It is the Exhaust Gas Temperature (EGT). It only happens when the engine is left to idle for to long. Prolonged idling is bad for a diesel. The EGT at prolonged idle falls too low to completly burn the fuel that gets injected. The unburned fuel tends to collect on the valves and valve stems in the head and hardens over time. This can cause the valve to stick inside the valve guide and ends up deforming the push rods mainly, and sometimes the rocker arms and lifters. It happens more in vehicle engines than in generator or pump engines. Like in fire trucks, ambulances and big rigs. For emergency vehicles its when they stay at the scene of an incident and leave the engine running. There is a fix to this that some manufacturers use which is to install a high idle system to raise the RPM's up which brings up the EGT's. This can be as simple as a stick wedged between the seat and pedal or can be a knob to pull or a button to engage the high idler. As a general rule 1000 RPM is usually sufficient to prevent wet stacking. A diesel generator that consistently runs at 1800 RPM with no idle feature will not have problems with wet stacking becuase the engine speed is more than enough to prevent wet stacking, even with no load. |
| oldtimer | Garr: A 3-phase 120/208 volt generator can be easily wired to produce 120/240 single phase (residential) power ONLY if it is 12 wire genset. That is to say, every one of the six windings has both ends brought out to the connection box. Many gensets do not have all 12 wires brought out but windings are made up inside and insulated, where they cannot be touched and no amount of figuring will help. This is where a single phase 208 volt primary to 120/240 volt secondary transformer has to be used (with loss of output). My surplus military 5 KVA 120/208 genset actually has a factory switch to switch from 208 3 phase to 120/240 volt single phase. |