A/C Start Up on Generator

[Alecadi]

I have a problem: the A/C would not start on the generator
A/C is old Cruis'air (probably 15k BTU, I'm not sure) the generator is 3300 nominal and 3600 peak, 120v 30A.

I was told that I need to put a relay and capacitor for the surge at start up and that will solve the problem
Also that a delay in the water pump start will help.

Can anybody help me with more details and explain a little more what I have to do in order to have the A/C starting correctly under generator?

Thank you

[HopCar]

I had the same problem. What you need is called a "Hard Start Capacitor". They are made by Supco. Here is a link: http://www.supco.com/images/pdfs/200...ion%202-51.pdf
They are very easy to install. If you look at the label on your AC compressor you will see a number called Locked Rotor Amps or LRA. This is very close to the number of amps you will need to start the compressor. It can be eight or ten times the amps required to run it. The hard start capacitor stores up energy and then gives out a burst to kick the compressor into motion. I think newer ACs are coming with these already installed. My little 5000 BTU AC needs over 3000 watts to start. With the hard start capacitor installed I can start and run it on a little 1000 watt Honda.

[Alecadi]

Originally Posted by HopCar

I had the same problem. What you need is called a "Hard Start Capacitor". They are made by Supco. Here is a link: http://www.supco.com/images/pdfs/200...ion%202-51.pdf
They are very easy to install. If you look at the label on your AC compressor you will see a number called Locked Rotor Amps or LRA. This is very close to the number of amps you will need to start the compressor. It can be eight or ten times the amps required to run it. The hard start capacitor stores up energy and then gives out a burst to kick the compressor into motion. I think newer ACs are coming with these already installed. My little 5000 BTU AC needs over 3000 watts to start. With the hard start capacitor installed I can start and run it on a little 1000 watt Honda.

THANKS A LOT!!

[HopCar]

You're very welcome. Let me know how it works out. You can probably buy the hard start kit locally from a refridgeration supply house. They aren't expensive.

[Vyndance]

Is this a new install or has it worked in the past?

[Alecadi]

Gen is new. A/C was there already.
Will install a Supca Hard start SSP 6 as soon as possible

[David M]

There are also capacitor start motors in case the first solution does not work.

[Alecadi]

We tried SSP6 doesn't work...
A/C specialist recommend installing the Crusair "soft start" kit. Not cheap.. but the Admiral will be happy if we managed to have the A/C working.
Somebody suggested that the gen being new, the engine has to be broken down a few 10 hrs before having really an opinion... ??? I'm puzzled by the comment

[Alecadi]

The soft start kit will be installed next Friday.. let's hope the problem will be solved.

[CarlF]

If the soft start doesn't work, another solution is something like a Victron Inverter/Charger. These can use the inverter to provide extra power from the batteries while passing through the the power from the genset. Since it's only for a second, the batteries have more than enough capacity.

This only makes sense if you need a new inverter/charger. Of course, this is even more money to solve a problem that doesn't seem like it should have been a problem in the first place. But this is a boat......

Carl

[Alecadi]

Originally Posted by CarlF

If the soft start doesn't work, another solution is something like a Victron Inverter/Charger. These can use the inverter to provide extra power from the batteries while passing through the the power from the genset. Since it's only for a second, the batteries have more than enough capacity.

This only makes sense if you need a new inverter/charger. Of course, this is even more money to solve a problem that doesn't seem like it should have been a problem in the first place. But this is a boat......

Carl

Thanks
Where can I get more details on this?

[s/v Jedi]

Originally Posted by Alecadi

Thanks
Where can I get more details on this?

It's called "Power Assist":

Power connections to provide all the power you need are not always available. That’s why Victron Energy developed Power Assist. This feature monitors power consumption and supplies additional power to prevent overloading. The Quattro can temporarily turn a 16A connection into 38A and a 5kVA generator into 10kVA. No other brand offers better functionality in this arena than the inventor: Victron Energy.

ciao!
Nick.

[Alecadi]

Originally Posted by s/v Jedi

It's called "Power Assist":



ciao!
Nick.

Thanks Nick
Alec

[capn_billl]

If this is a new installation, follow the above. If this is an old, clean and reconnect ALL wires from the generator to the Ac unit. Mine was having trouble starting, and I found a 40volt drop from generator to AC during startup. New connectors fixed this.

[Alecadi]

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