Hello again. I am an electrical contractor, but my specialty is not in Generators. I installed an 11k Generac through a service rated ATS. The service is 200A, and obviously the generator is not "capable" of serving a 200A load. The inspector requested a load calc and service calc for the home. Also, the the generator has a 50A breaker on the unit itself. The ATS came as a set with the generator. There are 3 load shedding modules available in the ATS and I have been researching the actual load shedding devices but I don't understand if I need one for each load to be shed, or if there is one available that is listed for use with this generac setup which will shed 3 large loads by itself. If anyone has any first hand experience with this, I am all ears. Again, this is not my wheelhouse at all, so please be gentle and use small words. Thanks guys.
Load Shedding
- Thread starter jcardwell
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Generac has really done some innovative things with their load shed and there are some guys here who may explain the particulars but, unless things have changed, the connections points you see are dry contacts and designed to switch interdependent loads such as the 24v control on the HVAC, etc,.. so normally each load shed would be controlled by one of the sets of contacts but if you wanted to install relays at multiple locations you could control any number of devioces off one contact.
I'm looking for as simple of a solution as possible. The units that I have been contemplating are all NEMA 3 which I would install inside anyway, but I want something (some kind of contactor) that I can mount in a box or that comes in its own box, and might connect to the cabinet of the ATS via offset nipple, or the like. The part that I don't understand entirely is the low voltage connection between the modules in the ATS and the actual load shedding device. Has anyone out there worked with a setup like this before? Again, break it down for me barney style please. Thank you all!
- Location
- New Jersey
- Occupation
- Journeyman Electrician
Aren't these modules the actual load shedding device? If so you would just rout the control circuit for the load(s) typically the AC unit through the dry contact of the load shed module. When the ATS call for load shed the contact opens and shuts down the AC.
cpinetree
Senior Member
- Location
- SW Florida
You probably should get with your generac rep, but short of that, their website has some info also about their load shed devices.
1) You may shed AC loads direct through the dry contacts on the transfer switch.
2) Using Generac SMM modules (http://gens.lccdn.com/GeneracCorporate/media/Library/content/all-products/transfer-switches/residential-transfer-switches/0L1500-B-SMM-Module.pdf)
You can load shed addtional loads, I believe up to 50amps per module.
They have a dial setting that controls the order of how they are shed. The contactor will drop the load when the power is below a certain Hz (maybe 58Hz?). The units can be installed at the panel or at the load - No low voltage wiring required -
You feed from the breaker to the SMM module then to the load. I think you can use up to 8 SMM modules per transfer switch (Check your transfer switch documentation)
You should easily be able to have the 11kw generator work with if you shed the Range, water heater, dryer, and another larger load using the SMM modules as well as running the AC through the dry contacts from the transfer switch.
Manual for the SMM modules: http://www.electricgeneratorsdirect.com/manuals/6873%20Manual.pdf
1) You may shed AC loads direct through the dry contacts on the transfer switch.
2) Using Generac SMM modules (http://gens.lccdn.com/GeneracCorporate/media/Library/content/all-products/transfer-switches/residential-transfer-switches/0L1500-B-SMM-Module.pdf)
You can load shed addtional loads, I believe up to 50amps per module.
They have a dial setting that controls the order of how they are shed. The contactor will drop the load when the power is below a certain Hz (maybe 58Hz?). The units can be installed at the panel or at the load - No low voltage wiring required -
You feed from the breaker to the SMM module then to the load. I think you can use up to 8 SMM modules per transfer switch (Check your transfer switch documentation)
You should easily be able to have the 11kw generator work with if you shed the Range, water heater, dryer, and another larger load using the SMM modules as well as running the AC through the dry contacts from the transfer switch.
Manual for the SMM modules: http://www.electricgeneratorsdirect.com/manuals/6873%20Manual.pdf
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