How To Set Image Generator?

I have question regarding ATS (automatic transfer switch) panel for generator set?

• I recently purchsed a 5.5 KVA Natural gas genset. I got ATS panel installed so that I may sleep in peace specially in nights (its very hard to manually start stop the generator in nights). Things were going fine till yesterday.. Here is what started happening from yesterday: When the Main supply (Government power supply) is OFF, generator automatically starts and takes the load normally.However, after few minutes of operation, like between 5 - 20 minutes, generator will automatically shut down as well as generator side contactor gets open in ATS panel. Now, interesting thing is that when generator shuts down, I go to the ATS panel & I move the ATS switch position from "automatic" to "0". and after some seconds i again move the ATS switch from "0" to "automatic", generator gets started and takes the full load normally and thereafter nothing happens till Government supply is available. Though I am not expert in this field, but being a Mechanical Engineer i can guess that some thing is related to SHUT DOWN of government supply.. Anybody can help me on this (Please aviod advising for calling the generator technicians as they will take another 8-10 days to attend my complaint) Onething I forgot to mention that I have checked all important things in generator like Gas inlet hose, lube oil level, spark plug, cooling fan (as this is air forced cooled gen set)..all are working fine... Regards,

• Answer:

  I am assuming that the "start" command is a voltage relay that falls out when relay fails to sense utility (government) power and normally closed contacts initiate a generator start after a brief time delay. Once the generator starts, a voltage relay on the standby power line from the generator set transfers power to the generator. Once utility power is restored, the transfer switch transfers power back to utility power and the generator goes through a cool down cycle and then shuts down. The only thing that should prematurely shut down the generator set and switch the transfer switch is a shutdown signal from a group fault relay. Depending on what fault sensors/switches may be on your engine; high temperature, low oil pressure, low or high voltage or frequency, etc; a signal from any one of these sensors would activate the group fault relay and prematurely shut down the generator as you experienced. When you switch the auto-manual-off switch to off, or "0", I am guessing that you reset the group fault relay which allows the engine to automatically restart when you switch back to "auto". First, check voltage and frequency of the generator when the generator is under normal load. If the generator is equipped with a voltage and frequency relay, and if voltage regulator or engine governor is improperly adjusted, you could get a shutdown when the load fluctuates causing the voltage or frequency to dip below a minimum set point. If voltage and frequency look fine, try to identify the fault signal terminal of the group fault relay. If this terminal is "hot" or has control voltage after the engine shuts down then you have an undiagnosed fault condition in the generator, a bad fault relay or bad fault sensor. Fault sensors may include over/under voltage and frequency, low oil pressure, high/low temperature, etc. Check for continuity across the various fault sensors and relays. A closed fault sensor could be due to an actual fault condition, or a faulty sensor. I have found that engine sensors fail periodically on small generator sets due to engine vibration. It is sometimes difficult to diagnose this problem because they can close periodically, resulting in a shutdown, but test normal once the engine shuts down. I have wired a temporary latching relay on these sensors so I can tell which sensor is causing the problem.