JonInNY
I'm just curious about this...

Supposing there's a utility failure and the generator is purring away just fine. The weather is warm and fine, and I don't need to run the generator.

My dealer said just turn the generator to "off", but I'm not sure how wise that is under load. I could always shed the loads at my main breaker and then turn off, and reverse when I want to turn the generator back on.

If I don't want to go to the trouble of opening up the ATS and going through the manual transfer procedure, is it okay to turn off the generator that way?

I look forward to your responses,
Jonathan
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Skip Douglas SkipD
You always want to turn off the load for a while (~30 seconds minimum) to allow the generator to cool before turning off the engine. You can do that with the breaker in the generator or the generator breaker in the transfer switch. It would be prudent, though, to turn off any heavy loads (particularly motorized loads) with their own switches first. That could help to save contact surfaces in the breakers.
Skip Douglas
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Canada_Guy
JonInNY;36760 wrote:
I could always shed the loads at my main breaker and then turn off, and reverse when I want to turn the generator back on.


You got it. Basically as Skip said. Shed the loads. Wait a minute or so, then turn the generator off.

To start it back up while the utility is still off, start the generator. Let it warm up 30 seconds or so, then restore the loads one breaker at a time.

This allows for graceful load shedding and restoring.

PS: I would have concerns on a dealer that instructed you to "just shut the generator off"
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Hodgy
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From my owners manual, section 3.5, on my 17 kw Honeywell here are the instructions for turning off the generator while under load.


3.5 — Turning the Generator Off When Operating Under Load
NOTE: Important! To turn the generator off during prolonged utility outages to perform maintenance or conserve fuel, follow these simple, but important steps:
To turn the generator OFF (while running in AUTO and online):
1. Turn OFF (or OPEN) the main Utility disconnect.
2. Turn OFF (or OPEN) the Main Line Circuit Breaker (MLCB) on the generator.
3. Turn the generator OFF.


To turn the generator back ON:
1. Put the generator back into AUTO and allow to start and warm-up for a few minutes.
2. Turn ON (or CLOSE) the MLCB on the generator.
The system will now be operating in its automatic mode. The main utility disconnect can be turned ON (or CLOSED), but to shut the unit off, this complete process must be repeated.


As Skip said, shed any heavy loads to save the contact surfaces on MLCB and the HLCCB.


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JonInNY
Thank you all for your responses!
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Hodgy
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Jon, I went one step further and posted 3.5 in the generator and 3.5 and 3.6 on the ATS.

Here is a video showing both of those and the shed roof. I think those instruction decals should have been installed at the factory or supplied for application upon installation.

[url]https://www.youtube.com/watch?v=e4bQbkQYTgE[/url]


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Birken Vogt
Hodgy;36765 wrote:
3.5 — Turning the Generator Off When Operating Under Load
NOTE: Important! To turn the generator off during prolonged utility outages to perform maintenance or conserve fuel, follow these simple, but important steps:
To turn the generator OFF (while running in AUTO and online):
1. Turn OFF (or OPEN) the main Utility disconnect.
2. Turn OFF (or OPEN) the Main Line Circuit Breaker (MLCB) on the generator.
3. Turn the generator OFF.


I wonder if whoever wrote this was not thinking or writing from a script. No reason to do anything to the utility disconnect.

I leave the utility disconnect on when I shut mine down overnight during a prolonged outage. Otherwise the utility could come back online when I am sleeping or away and I would not get any power from them.

Otherwise there is good advice here, try to drop any loads possible by their own switches and then open the circuit breaker under light/no load.
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techntrek
I follow the same shutdown steps, but as I've described here before, I modified mine so I can do it from inside. I added a second switch in series with the on/off switch inside the generator, and I modified the ATS (2 changes) so I could control it remotely, too. The difference between what I do and the "normal" way, is I switch the ATS to utility to remove the load from the generator, and later switch the ATS back to the generator after restarting. This configuration still allows the power to return to the house immediately if the utility power comes back.
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Skip Douglas SkipD
techntrek;36777 wrote:
I follow the same shutdown steps, but as I've described here before, I modified mine so I can do it from inside. I added a second switch in series with the on/off switch inside the generator, and I modified the ATS (2 changes) so I could control it remotely, too. The difference between what I do and the "normal" way, is [B]I switch the ATS to utility to remove the load from the generator[/B], and later switch the ATS back to the generator after restarting. This configuration still allows the power to return to the house immediately if the utility power comes back.
Are you manually toggling the transfer switch with power flowing to do this? If so, that's a good way to burn contacts and possibly have a dangerous arc flash occur.
Skip Douglas
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UPS
Birken Vogt;36769 wrote:
I wonder if whoever wrote this was not thinking or writing from a script. No reason to do anything to the utility disconnect.

I leave the utility disconnect on when I shut mine down overnight during a prolonged outage. Otherwise the utility could come back online when I am sleeping or away and I would not get any power from them.

Otherwise there is good advice here, try to drop any loads possible by their own switches and then open the circuit breaker under light/no load.


Probably for the same reason a ladder has a warning label on the top step that says "This is not a step" or takeout coffee has a warning "contents hot" - risk of legal liability.
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Birken Vogt
SkipD;36780 wrote:
Are you manually toggling the transfer switch with power flowing to do this? If so, that's a good way to burn contacts and possibly have a dangerous arc flash occur.


No different than when the generator controller does it itself upon retransfer to utility.
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Canada_Guy
SkipD;36780 wrote:
Are you manually toggling the transfer switch with power flowing to do this? If so, that's a good way to burn contacts and possibly have a dangerous arc flash occur.


Birken Vogt;36784 wrote:
No different than when the generator controller does it itself upon retransfer to utility.


I would say it is different. When the controller activates the pull-in coil, it's a very quick contact closure. There will be an arc, but it will be a very short duration.

When closed manually, it's much slower, maintaining the arc for a longer time probably causing more contact erosion.
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Skip Douglas SkipD
Canada_Guy;36785 wrote:
I would say it is different. When the controller activates the pull-in coil, it's a very quick contact closure. There will be an arc, but it will be a very short duration.

When closed manually, it's much slower, maintaining the arc for a longer time probably causing more contact erosion.
Precisely. That difference can be huge.
Skip Douglas
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Hodgy
Birken Vogt;36769 wrote:
I wonder if whoever wrote this was not thinking or writing from a script. No reason to do anything to the utility disconnect.

I leave the utility disconnect on when I shut mine down overnight during a prolonged outage. Otherwise the utility could come back online when I am sleeping or away and I would not get any power from them.

Otherwise there is good advice here, try to drop any loads possible by their own switches and then open the circuit breaker under light/no load.




The people who wrote it are the same people who thought a 5 minute exercise was a good idea !



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JonInNY
Hodgy;36790 wrote:
The people who wrote it are the same people who thought a 5 minute exercise was a good idea !.


That's all the time I spend exercising myself... once a week! LOL! Thanks to everybody again for all the great advice!

J
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techntrek
I did say I modified ATS and generator so I could operate them remotely. The ATS is switched electronically in both directions, which is why I had to make two modifications to the ATS. A switch in series with the 12 volt control line and I moved the power for the utility coil over to the fuse for the generator coil.
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Birken Vogt
Canada_Guy;36785 wrote:
I would say it is different. When the controller activates the pull-in coil, it's a very quick contact closure. There will be an arc, but it will be a very short duration.

When closed manually, it's much slower, maintaining the arc for a longer time probably causing more contact erosion.


Agreed, just that it appears to me he is doing it electrically and not manually. That is why I said no different.
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