Generator + Hughes Watchdog = AC won't start

[SuwanneeDave]

My trailer has a Broughton A3400 13500BTU AC with a soft start. The specs say 14 amps cooling and max amps of 15.5. A Hughes Watchdog electrical protector is hardwired in the system. When I try to run the AC on a Honda 2200i generator, the Hughes cuts the power when the compressor tries to start. Nothing else is on. Is this just because the generator is ramping up voltage and/or current too slow? It is not on Eco mode. the AC runs fine on shore power or 2000W inverter.

 

[Kirk]

I'm not experienced with the Hughes Watchdog specifically or with the brand of air conditioner that you have but I do know that with most portable generators you need to use a neutral to ground bonding plug on them for them to work with any of the line monitor type of power protection devices. The reason is that shore power pedestals are connected that way but portable generators are not and they are designed for shore-power.

 

[SuwanneeDave]

thanks. I do have a bonding plug.

 

[Gary RV_Wizard]

Your problem is that a compressor has a momentarily extreme high amp load at start up. Some a/c compressors may draw 2x or more the running amp load for 0.5 seconds and not taper off to the rated run-amps for as much as 2-3 seconds. Your Watchdog and even the generator itself will almost surely react to that. Unlike mechanical circuit breakers, electronic monitors are extremely sensitive and quick-acting.

The a/c soft start is supposed to alleviate that problem to some extent, but apparently not enough.

Hughes uses "Watchdog" name on several power monitoring/protection products. What model of Watchdog product are you using? Does it give an error code when it shuts down?

 

[SuwanneeDave]

Gary; it is the Hughes PWD30-EPO. It shows E-1 voltage error. The generator is not cutting its circuit breaker so I think it is the Watchdog reacting to a momentary low voltage. I think I will switch to a pedestal mounted version so that when using the generator it is not in the loop.

 

[SuwanneeDave]

The alternative is to get a bigger generator.

 

[John From Detroit]

The surge is too grate for the genny so there is a voltage drop.
You might try starting fan THEN starting Compressor
Also you have other loads on the genny like the converter. possibly the fridge and other things.
You are so close to the genny max that even a small additional load might do it in.

 

[SuwanneeDave]

John; this AC unit starts the fan before the compressor. No other loads were on. The generator will start the compressor if I bypass the EMS so I think that is what I will have to do

 

[Ray-IN]

There ya go! The EMS is doing what is designed to do, limit current draw to 80% of available amperage. If you have the onboard battery charger turned on that reduces available amperage.

 

[John From Detroit]

John; this AC unit starts the fan before the compressor. No other loads were on. The generator will start the compressor if I bypass the EMS so I think that is what I will have to do

No other loads.. You disabled the converter? Those can draw up to around 1,000 watts (though 100 is more common but you only have about 100 watts of cushion .

 

[1stimerver]

You might want to contact Safe start and ask them. I phoned them and told them the size of my AC and the name/model # of my genny and they told me, based on their experience, it would not work with that combo. I really appreciated their honesty.

Safe travels and all the best.

 

[SuwanneeDave]

I have confirmed it is the EMS. I took it out of the system and the AC will run on the generator.