Generator transfer switch ?

[metschers]

Does anyone know whether or not you can operate a Generac 22kw whole house generator with a manual transfer switch instead of an automatic transfer switch?
Currently I’m setup with a Eaton 200amp manual transfer switch. I’ve been using a smaller portable generator in the past. I’m fine when the power goes off, stepping out the side door, pulling the huge lever on the MTS box, firing up the generator, selecting the important breakers ( the ones are already marked)...etc.
I spoke to Generac, I sure due to liability/warranty issues they couldn’t give me an answer. They did said the generator wasn’t designed to be used without an automatic transfer switch.
Basic it would be like running a major overkill portable generator, there again everything would just be manual instead of automated.

Any help would be most appreciated!
Thanks Guys,
SteveM

 

[rlitman]

I run a megawatt class Generac generator at work. Coincidentally I will be switching it on tonight. Even THAT can be switched manually.

 

[yeldogt]

I don't see why not ... I guess the question would be why?

Mine has an "off" .. so you can keep it "off" if you don't want it to respond to every power loss. I'm not at my one place very much in the summer -- we lose power all the time (short) .. there is no need for it to go on in the summer. The winter is a different story.

With a 22kw -- you are going to have to hardwire it all in anyway .. why not have all the benefits?

 

[wyliesdiesels]

Does anyone know whether or not you can operate a Generac 22kw whole house generator with a manual transfer switch instead of an automatic transfer switch?
Currently I’m setup with a Eaton 200amp manual transfer switch. I’ve been using a smaller portable generator in the past. I’m fine when the power goes off, stepping out the side door, pulling the huge lever on the MTS box, firing up the generator, selecting the important breakers ( the ones are already marked)...etc.
I spoke to Generac, Im sure due to liability/warranty issues they couldn’t give me an answer. They did said the generator wasn’t designed to be used without an automatic transfer switch.
Basic it would be like running a major overkill portable generator, there again everything would just be manual instead of automated.

Any help would be most appreciated!
Thanks Guys,
SteveM

there is no electrical code prohibiting it if thats what youre asking.

they probably have a clause in their warranty mandating it be used with an ATS.

Try calling a dealer and asking them

 

[Norcal]

Look at another brand Generjunk is not the only one out there.

 

[metschers]

I’m trying not to buy an expensive automatic transfer switch since I had a manual one. My power goes out several times a year for 10 or so hours at a time. In 2007, I was out for 9 days due to ice. Man, do you appreciate electricity after that.
Anyway, thanks for all the replies.
Thanks again guys!!
As always the Garage Journal has the answers.

SteveM

 

[mm08822]

For generac:
The gen uses voltage from the xfer switch to determine if grid power is present.
It also provides trickle charge power to the battery.
Also provides power for cold weather kit(s).
You lose these features.

The gen sequences the xfer sw as follows when gen in auto:

• loss of grid power detected
• choke on
• crank
• voltage detected from spark plugs
• 30 sec warm up
• Checks gen voltage & freq within spec
• If in spec, gen sinks xfer sw coil
• Xfer sw closes to gen/opens from grid

CB at gen needs to be (and should always be) closed to get gen power back into xfer switch

Upon grid power restored:

• Gen verifies voltage and freq within minimum ranges/time periods
• Gen opens sink to xfer sw coil
• Xfer sw closes to grid/opens from gen
• 2 min cooling period for gen
• Gen shutdown

With gen switch in off, gen won’t run

With gen switch in manual, it will immediately start (and stay running until placed to off/auto)

• choke on
• crank
• voltage detected from spark plugs
• Gen runs (no actionable check of voltage & freq within spec)

As long as gen cb is on, voltage present at xfer switch lugs
(You should shut down all large loads in house panel)
Manually operate xfer sw

You will continually get blitzed with warnings/alarms. They will be annoying.

Consider putting your current xfer sw on ebay. Buy a gen and xfer switch paired for each other - i.e. - same mfr.

Do not have the house connected while starting or stopping the gen (any gen).

**********

You will also lose the exercise feature if unit stays in "off" mode.

 

[rlitman]

That sound similar to, but not quite what I've seen in several Generac transfer switches I've worked with.

What I've seen is that a pair of wires leads one phase from the transfer switch to the generator. With a little creativity (think fused disconnect) you could source that from the utility side of your MTS, and use that to power your winter kit and charger. The auto-start within the generator is controlled by this utility power. When it is off, the generator starts.

The actual transfer is controlled by logic within the ATS. There are a three solenoid coils within the switch. One pulls in the contacts, while the second selects the contacts to use (utility or emergency). The last coil trips the latching mechanism to release contact. The control board in the ATS gets its power from both sources, and uses whichever source is available to fire the coils.

 

[metschers]

WOW!!
That’s a lot of great information and advice.
Thanks Guys

 

[ihateminimumwage]

Generac finally started offering an "off grid" mode for their home standby machines that makes it a two wire start (like every other brand out there) and cuts out all the ATS controlled stuff.

If you're going air cooled HSB (anything under 25kW nowadays), Kohler and Briggs put out a better product that will be far easier to work with a manual transfer setup.

 

[mm08822]

That sound similar to, but not quite what I've seen in several Generac transfer switches I've worked with.

What I've seen is that a pair of wires leads one phase from the transfer switch to the generator. With a little creativity (think fused disconnect) you could source that from the utility side of your MTS, and use that to power your winter kit and charger. The auto-start within the generator is controlled by this utility power. When it is off, the generator starts.

The actual transfer is controlled by logic within the ATS. There are a three solenoid coils within the switch. One pulls in the contacts, while the second selects the contacts to use (utility or emergency). The last coil trips the latching mechanism to release contact. The control board in the ATS gets its power from both sources, and uses whichever source is available to fire the coils.

Depends on the xfer sw series I guess.

The 100a and 200a RTS shipping with the guardian air-cooled unit operate as I stated.

6 control wires go between gen and xfer sw.
2 - utility sensing
1- trickle charger
1- 24vdc
1 - vdc com
1 - xfer

There is 1 transfer relay (ice cube) and 2 sol coils - utility closing & gen closing. No other sol coil.

The transfer logic is performed in the gen controller. It drives the transfer relay. The transfer relay connects 240v to either coil depending on its state.

The only logic in the xfer sw is for load shedding.

Supplying power from gridside of manual xfer swtich can be done, but you start adding more hardware - taps, fused disconnect, fuses. It's easier to just buy the matching parts and be done with it.

 

[metschers]

After getting great advice from you guys and others, I agree with mm08820. I’m going to switch out my manual transfer switch for the matching automatic transfer switch.
Overall less time, maintenance, etc.

It’s just money.....I’ve never seen a uhaul behind a hearse.

Anyway thanks again for everyone’s input.

SteveM

 

[yeldogt]

After getting great advice from you guys and others, I agree with mm08820. I’m going to switch out my manual transfer switch for the matching automatic transfer switch.
Overall less time, maintenance, etc.

It’s just money.....I’ve never seen a uhaul behind a hearse.

Anyway thanks again for everyone’s input.

SteveM

Make sure you look at the hook up before you purchase -- as the new models come out they have more "stuff" .......controls and more wires.

I went with the second control -- so I could do everything direct from inside the house w/o thinking about the internet. That required more wires -- some units have different ways the battery is charged and when and if it needs a cold start kit. Also -- some places allow the simple systems to use a bundled cable as Generac uses .. other places do not.