A/C Start Up on Generator

[capn_billl]

Originally Posted by teejayevans

My experience is with a Frigidare 5000 BTU AC and Honda 1000 is:
normal amp draw when running is ~5amps (it starts around 4.8 and slowly climbs to 5.2 for some reason).
When set on low, Fan draws about .5 amps, but when compressor kicks in it goes up to 14 amps, the gen has a 4 second delay before disconnecting, with eco-throttle on, sometimes it recovers in 4 seconds and sometimes it doesn't.
One thing I can't explain, when set to high, the draw is the same, I'm using kill-a-watt to measure the amps.
Tom

The current draw on an A/C is not relative to the temp setting. The fan speed can have a small effect, but depending on the circuitry used to control fan speed it may even go up on lower speeds.

[capn_billl]

The old A/C units required very large starting currents , (3-10times normal current draw), for the compressors. My generator is 10KW for two 12kBTU A/C units, of which I can only start one at a time. The 3300 portable generator is very small for a 15KBTU A/C unit. The new A/C units with rotary or scroll compressors have very small starting currents, (1.5-2 times normal current). I know you don't want to hear this, but either a bigger generator, or a new A/C may be your only option. You can call the generator manufactorer and see what is the max inrush current it can handle, and compare to inrush current of A/C, remember the more the voltage drops the more current it takes to start.

[Alecadi]

Originally Posted by capn_billl

I know you don't want to hear this, but either a bigger generator, or a new A/C may be your only option. You can call the generator manufactorer and see what is the max inrush current it can handle, and compare to inrush current of A/C, remember the more the voltage drops the more current it takes to start.

What about the indications given by the gen people? see post #25.

[teejayevans]

Originally Posted by capn_billl

The current draw on an A/C is not relative to the temp setting. The fan speed can have a small effect, but depending on the circuitry used to control fan speed it may even go up on lower speeds.

HI LOW was referring to the cool setting, not the thermostat.
Tom

[s/v Jedi]

Originally Posted by Alecadi

What about the indications given by the gen people? see post #25.

Nah, those instructions are for tuning the voltage regulator to set the voltage right. Your voltage is right; it only comes down because of the overload.

You can't run that A/C from such a genset. With a Victron inverter/charger ith power assist? may be, but I still wouldn't want that genset to run my A/C.

ciao!
Nick.

[HopCar]

Just for fun, can you borrow a Honda and try it?

[dropanchorfor3]

Originally Posted by Alecadi

We isntalled the soft start but doesn't work either
and yes we have a voltage drop of more than 30v...

Chances are if you have a voltage drop of 30 volts you may have a bad contact relay which supplies voltage to the compressor the T- stat board, fan etc. A hard start is measured in microfarads and so is a start and run capacitors. If either one is not supplying enough voltage tp a certain componet your a/c will not run. Run caps have a start, herm, and c for compressor terminals. Run caps are usually around a 35+5 cap. I'm not sure what yours will be most likely smaller in size and in number 15+5 cap etc. They supply voltage to the compressor, fan. Make sure you have the right voltage coming in to your a/c 120v and 24v coming out. Check the voltage on transformer for high and low voltage.

[skipmac]

From all evidence, including the reply from the manufacturer here is the problem.

1. When an A/C unit first starts it draws a lot of extra power.

2. The generator does not have enough power for the startup.

3. The adjustments will not make any difference.

Bottom line, the generator is too small to work in the current system. You might be able to add a capacitor that will reduce the start up power but it might not be enough.

[dropanchorfor3]

It will draw extra power, I for got that you were using a generator upon start up. The other accessories will not help then, sorry I thought I could help. So you need a higher kW generator?

[Beausoleil]

I haven't seen any talk about the true capacity of this generator. According to Boliy, this Pro3600 variable speed generator is only capable of 3000W continuous, 3300W max.

They claim it can start up an RV 15k BTU A/C unit, but don't specify a make or model. It may be able to start up a modern unit, but an older unit like Alecadi has is a big if...

[capn_billl]

Originally Posted by teejayevans

HI LOW was referring to the cool setting, not the thermostat.
Tom

My statement stands, a compressor only has one speed, and power draw. Any settings on AC unit only effect fan speed, or cycle time, neither change current draw.

[capn_billl]

Originally Posted by Beausoleil

I haven't seen any talk about the true capacity of this generator. According to Boliy, this Pro3600 variable speed generator is only capable of 3000W continuous, 3300W max.

They claim it can start up an RV 15k BTU A/C unit, but don't specify a make or model. It may be able to start up a modern unit, but an older unit like Alecadi has is a big if...

That says it. no one wants to tell this guy to go out and spend a lot of money for new stuff, but the general rule is Big AC = Big Gen; Small AC = Small Gen. Anything else is asking for trouble. Newer AC units use a LOT less power than old ones, especially on startup.

[S/V Illusion]

I didn't bother reading through 3 pages of comments so if this is redundant, please ignore.

A simple hard start cap might solve your problem as it has countless other folks:

RV Air Conditioner Hard Start Capacitor | ModMyRV

[dropanchorfor3]

Originally Posted by capn_billl

My statement stands, a compressor only has one speed, and power draw. Any settings on AC unit only effect fan speed, or cycle time, neither change current draw.

Exactly right, the amp draw on a compressor will drop a little after it starts and runs. I know on commercial water towers there is a new style of compressor using magnitaion. Magnets are used inside the compressor as apposed to a coil. Making the compressor the most efficient on the market.
I will find out if they are making marine a/c's and or portable a/c units using the same technology, if so problem should be solved as far as voltage- amp draw.

[dropanchorfor3]

Originally Posted by S/V Illusion

I didn't bother reading through 3 pages of comments so if this is redundant, please ignore.

A simple hard start cap might solve your problem as it has countless other folks:

RV Air Conditioner Hard Start Capacitor | ModMyRV

If he has a droppage in volts a hard start will not help. Unfortunately...