Whole house backup generator

Are you on IREA?

I'm interested in what you decide on because I plan to include a backup gen system in a remodel. I'm also on propane and plan to use that for the generator because it has big storage, doesn't deteriorate, and has lower engine maintenance. I have a 5K Honda gen but it isn't set up for automatic.

I know a fellow in Ned who sells and services GE whole house generators, but I haven't studied the options.

Quote:

---

Originally Posted by kwando

Are you on IREA?

---

Yes.

https://gensizer.assurancepower.com/...ouse&Itemid=55

A Load calculator for generator sizing. I put some numbers in quick. Figured on a 3 ton Ac. Came out as 22kw. To meet code with an automatic transfer switch for the whole house you either need to size generator to load calc or rent a power logger for 30 days to see what your peak kw was. I don't know if you power company can give you that information or not.

Screenshot of sample load calc.

Attachment 76160

NEC 220.87

Quote:

---

220.87 Determining Existing Loads. The calculation of a feeder or service load for existing installations shall
be permitted to use actual maximum demand to determine the existing load under all of the following
conditions:
(1) The maximum demand data is available for a 1-year period.
Exception: If the maximum demand data for a 1-year period is not available, the calculated load shall
be permitted to be based on the maximum demand (measure of average power demand over a 15-
minute period) continuously recorded over a minimum 30-day period using a recording ammeter or
power meter connected to the highest loaded phase of the feeder or service, based on the initial
loading at the start of the recording. The recording shall reflect the maximum demand of the feeder or
service by being taken when the building or space is occupied and shall include by measurement or
calculation the larger of the heating or cooling equipment load, and other loads that may be periodic in
nature due to seasonal or similar conditions.
(2) The maximum demand at 125 percent plus the new load does not exceed the ampacity of the feeder or
rating of the service.
(3) The feeder has overcurrent protection in accordance with 240.4, and the service has overload
protection in accordance with 230.90.

---

NEC 702.4

Quote:

---

(B) System Capacity. The calculated load on the standby source must
be in accordance with Article 220 or by another method approved by
the authority having jurisdiction.
(1) Manual Transfer Equipment. The optional standby power source
must have adequate capacity for all equipment intended to operate at
one time as determined by the user.
Author’s Comment:
n When a manual transfer switch is used, the user of the
optional standby system selects the loads to be connected to
the system, which determines the system kVA/kW rating.
(2) Automatic Transfer Equipment.
(a) Full Load. The optional standby power source must have adequate
capacity to supply the full load transferred.

---

Quote:

---

Originally Posted by 00tec

My power company is absolute garbage. I have multi-hour power outages at least once a month, along with several "bumps" that take us down for short periods. Probably once a week. (I come home to reset clocks and such). I need a backup solution to run my house when this occurs.
Priority goes to maintaining climate in the house. I need to keep the house below 80 and above 65 or so. I am on AC and propane furnace. Well pump and pressure pump need to run, or I get no water, and I have a stand up deep freezer. 1620sq ft house, 3 bed, 2 bath, unfinished basement.

Need an automatic transfer switch for when I'm not home.
Looking at Generac, Briggs, Kohler, whatever. Any particular one to get? I'm thinking 12k+ watts. I have propane on site, but would actually prefer gas/diesel (but I know those get spendy).

---

My guess is your seeing the power drop when a gas compressor is started.

Quote:

---

Originally Posted by thedave1164

Propane would get real expensive for any real length run time, gasoline powered will be quite a bit cheaper than diesel.

that is all I got

---

I disagree that any extended use with propane would be much different from gasoline or diesel. Call your propane supplier and ask their experts what they think. I went with propane primarily because it is so much cleaner. Gasoline in storage for long periods degrades and additives increase the cost so that needs to be considered as well. Then all commercial generators made for gasoline will specify non-ethanol fuel. Very expensive. Now diesel could be a good choice but see how easy it can be had in your area using farm or non highway use fuel. About a 40 cent per gallon savings.


Sent from my iPhone using Tapatalk

I had a whole home one and I had 400 amp service for the home because I had a large home and lots of electricity being used in it. I had a Generac and transfer switch that could handle the whole load and never had an issue with it. Would do its weekly self test and come on by itself which was comforting to hear. Ran on propane out in the country north and east of Kiowa so I know what you are saying about not wanting to count on the electric always being there.