Time to check out the generator.

[ultrarunner]

Genset warmups have been discussed, but what about cool down? The manuals in several I've looked at recommend running the engine for 5 - 10 minutes with no load before shutting down. This is the manual page for the Kubota GL11000:

View attachment 1690916

I understand the need for a warmup period, but cool down? In any case, an automatic transfer switch takes neither into consideration.

As posted by several others, it may well be that the relatively low run time of a consumer grade genset is low enough to make these warm up and cool down cycles less important. However, IMO, it's the number of start-stop cycles that counts. The actual run time is irrelevant.

The number of recommended monthly, or quarterly, start-stop maintenance cycles will add up over time.

10 minute cool down while it monitors the stability of the circuit and if need be transfer back to carrying the load... Turbo Diesel.

Load monitoring for stability is a built in protection plus once load carried... even for a few seconds the generator keeps carrying for several minutes...

All 1995 tech and tier 0

 

[Up to the Axles]

The twin Cummins diesel powered generators in the basement of the building where I used to work, transfer from commercial to generator power in less than 5 seconds. What gives? Is there something magic about diesel engines used to power generators?

Many stationary plants are kept jacket-heated for rapid use. None more so than the backup power at a nuclear power plant; they are ready to accept loads in seconds.

Without them, you risk being the next Fukushima Daiichi.

 

[DarkBlack]

Many stationary plants are kept jacket-heated for rapid use. None more so than the backup power at a nuclear power plant; they are ready to accept loads in seconds.

Without them, you risk being the next Fukushima Daiichi.

The UPS generation I worked with took the load in milliseconds. Can’t get any faster than that

 

[ponytug]

The UPS generation I worked with took the load in milliseconds. Can’t get any faster than that

For critical loads, that's what I have always done. Enough UPS systems with the power and capacity to run the full load for ten minutes (aka as 20 min) to give the generators enough time to power up, warm up, and stabilize before the load was transferred. It helps the equipment under protection as they never lose power, and it can help the generator with the load transfer, especially if the UPS systems transfer at slightly different delay times.


All the best,

Peter

 

[DarkBlack]

For critical loads, that's what I have always done. Enough UPS systems with the power and capacity to run the full load for ten minutes (aka as 20 min) to give the generators enough time to power up, warm up, and stabilize before the load was transferred. It helps the equipment under protection as they never lose power, and it can help the generator with the load transfer, especially if the UPS systems transfer at slightly different delay times.


All the best,

Peter

I’m talking about a diesel generator UPS system, where the load never sees an interruption. No battery backup involved.

 

[5030]

. ? . Every generac standby, not portable, ive ever worked on has both. The control is not in the switch, its in the generator controls. Now,if the unit has been changed over to a 2 wire start, than all bets are off.

Both of mine do. The 21KW on Propane for the house and the 35KW JD Diesel unit that powers the shop and outbuildings. I believe (could be wrong as I don't pay a lot of attention to them) but I think 45 seconds before assuming the load and 2 minute cool down. Both are well over 15 years in service with zero issues (other than I had to replace the steel cab on the house unit because it was corroding away). It now has a new aluminum enclosure.

 

[bigtiller]

wouldn't we all like to have one of these?
It powers a cell phone tower in my field.

 

[Up to the Axles]

The UPS generation I worked with took the load in milliseconds. Can’t get any faster than that

100KW-1 MW UPSi are rather larger.

There are batteryless UPS's. I can't recall the name, but they are vertical shaft motor-generators with flywall mass. You could see them in datacenters. They run for 'n' seconds, enough of them for the Diesels to get up to speed.

 

[DarkBlack]

Very good. I’ve been waiting for someone to try to call me on the carpet for saying a diesel generator starts and carries the load in milliseconds.
Yes , a large 3ph 1,800 rpm motor/generator coupled to a huge flywheel. The moment a disturbance to a single sine wave on the line is detected, the computer instantly energizes the electric clutch to the diesel crankshaft , which is instantly ripped up to speed, and driving the load.
The building sees seemless power.
20 years. Average of almost daily starts. No warmup time. No engine rebuilds

 

[workinonit]

All power plants have very large UPS, battery banks and inverters. 125 VDC and 250 VDC battery banks. One for the emergency bus and one for the inverter. All of the nukes have backup generators for the critical aux equipment, usually in the megawatt range. Most NG and coal sites do not. They have the emergency bus so they can get the turbine offline and spun down without damage.