Burned up capacitor on generator

[Bycrick]

Like many things, capacitors are theoretically simple, but not all are created equal. When you look at the “ratings” you will typically see just the capacitance and the maximum voltage. But there are a number of other “ratings" that you will only find if you can research a real manufacturer’s data sheet. Temperatures, equivalent series resistance, maximum current and a number of others. Just matching the capacitance and voltage ratings is not enough. For example, a "motor starting" capacitor only passes current while the motor is starting, ie very intermittent duty. A motor-running capacitor carries current whenever the motor is running. The former is unlikely to last long in the latter application.

[crayiii]

Got the new cap in and all is well. One thing that I notice is that when the gen is started the hz display shows zero. As soon as I switch on a load like the water heater or battery charger it shoots up to 60 but I want to make sure that is normal.

[crayiii]

Also noticed that with a small load 30%, the voltage was reading about 130v. I didn't put anymore load on it to see if it dropped out of dear of freeing something. RPM is Rick solid at 3600 and the Hz was between 58 and 60.

[a64pilot]

Originally Posted by crayiii

Got the new cap in and all is well. One thing that I notice is that when the gen is started the hz display shows zero. As soon as I switch on a load like the water heater or battery charger it shoots up to 60 but I want to make sure that is normal.

It’s not normal for mine, but then I have an electric water pump so it never is at zero load.
Before installing the pump, I don’t think I monitored Hz.

[a64pilot]

Originally Posted by crayiii

Also noticed that with a small load 30%, the voltage was reading about 130v. I didn't put anymore load on it to see if it dropped out of dear of freeing something. RPM is Rick solid at 3600 and the Hz was between 58 and 60.

You can trim the voltage by changing the uf rating of the Cap.
However I’d consider 125V normal, I know you said 130 and that’s a little high.

Page 2 gives you the allowable tolerances
https://www.pge.com/includes/docs/pd..._tolerance.pdf

[crayiii]

Here's what I heard from the dealer:

On your boat, with everything set to on (aircon chargers water heaters) we had to crank up to 130 for the appliances not to shut down due to temporary low voltage.
All electric apparatus should be ok with voltage set between 110 and 140V.
Should you prefer to lower this voltage you will need a capacitor with slight lower capacitance.