Gray
From reading some other posts regarding A/C and genset sizing I started thinking about the issue.

The installed genset is the Honeywell(Generac) Model G0062602 16kW (natural gas) which is specified to produce 66.6 Amps rated maximum load current.

The installed A/C compressor shows 14.1 Amps RLA and 73.0 LRA at 208/230 volts.

My questions for the professionals:

1. Do these generators have any surge capability for motor inrush current (I know that some portable generators distinguish between surge and rated output)?

2. Without testing the A/C (too cold now until summer, and have never used it with the A/C since installation), does it seem likely that I will need a soft starter or am I within proper sizing for the
A/C? (There are no other large electrical loads; the house is natural gas, including heating, cooking, water and clothes dryer.)

Thank you
Quote
78buckshot
I have an older 13 -15kw running on natural gas, I can start and run my 3 ton a/c if I have no other major load at the time, when the a/c cycles the generator droops some but recovers pretty easy. Do you know the tonnage of your a/c? I would not hesitate to add the soft start as it will reduce the surge on the generator and a/c.
Quote
Gray
78buckshot;n60173 wrote:
Do you know the tonnage of your a/c?


Yes sir, it is a 3 ton unit.
Quote
Brian Baughman
The 16 kW generator has a surge capability of 130 Amps
Quote
grsthegreat
The easiest way to tell is try shutting down power manually next summer and turn on a normal load including the AC unit and see what happens. What ive found is the higher end AC and heat pump units (like Trane) seem to operate fine without a soft start, but the cheepo units like the Goodman AC that i used to have need either a soft start or a load shed module. after i replaced my cheep ac unit with an upgraded, but same tonnage unit, i no longer needed the load shedding. I have a soft start unit i purchased for my unit sitting on my shelf, but i don't think I'm going to install it. I have run across several heat pump units during my installs that refuse to start under generator load, but work great after i install the soft starter unit. So far i have not had any issues with strictly AC units running under generator load. I have no idea why there's any differences between heat pumps and AC operations, but that's been my experience.
Quote
Gray
Brian Baughman;n60180 wrote:
The 16 kW generator has a surge capability of 130 Amps


That surge capability sounds like it would have no problem with the starting inrush current (73.0 LRA). Thank you. I will be testing it come summer.
Quote
Gray
grsthegreat;n60182 wrote:
The easiest way to tell is try shutting down power manually next summer and turn on a normal load including the AC unit and see what happens. What ive found is the higher end AC and heat pump units (like Trane) seem to operate fine without a soft start,


The A/C is a Carrier model 24ACA4 series, with Carriers (proprietary) rating as "Good" (probably a subjective good, better, best scale). It is a 3 ton, single-stage scroll compressor and rated at 14 SEER / 11 EER.

It is about 10 years old but in good operating condition; it was installed when the house was built.

Thank you.
Quote