Electric Stove Reverse Polarity Indicator Only When Operating Off GenSet

I have an electric/alcohol stove in my boat. When plugged in to shore power (110V), the electric elements of the stove operate perfectly. When I switch from shore power to my Westerbeke generator, I get an indication of "Reversed Polarity" when I switch on the "Electric Stove" switch on the breaker panel. Based on the Reversed Polarity warning, I have never actually turned on the stove for electric use off the GenSet power as I am concerned about damage, shock, or worse.

Might I get an opinion from the forum on why this would occur on the GenSet but not when plugged in to shore power? All other systems (A/C, Ice Maker, Hot Water Heater, 110V side of Fridge) operate normally with both shore power and GenSet power and no reversed polarity indicator. Once again, only the electric stove on GenSet power indicates this problem. Is the issue in the stove wiring? If so, why would it indicate reversed polarity only when GenSet is providing the power?

Thanks in advance for your expertise and guidance.

Verboatin

Re: Electric Stove Reverse Polarity Indicator Only When Operating Off GenSet

That's normal. (reverse polarity light). When i disconnect from shore power, gen set or not the light goes red.The Reverse Polarity indicator light is mainly for S/P protection

There are occasions when a dock pedestal is wired incorrectly, and the consequences can be dangerous for your boat and your crew. This happens when the black and white wires are accidentally interchanged, which renders the green ground wire ineffective. That’s where the reverse polarity light on your distribution panel comes in. The ABYC requires that your panel either have an audible or visual alarm if you have reverse polarity, and that’s your signal to disconnect from shore power immediately. Incidentally, using an isolation transformer is another solution to this problem, but most boats use a reverse polarity light indicator instead.

This is common with inverters and generators on boats where there is no true "ground" and often means one piece of equipment or the other is getting confused by neutral being used as (wired to) ground.
Reverse polarity has nothing to do with the batteries with the exception that the genset runs the battery charger or the altenator on the genset is charging the house batteries

Re: Electric Stove Reverse Polarity Indicator Only When Operating Off GenSet

Hi Thalasso,

Wow, you provided an abundance of information in a very short explanaton! Well said and thank you! Based on your assessment, allow me this final question; I am safe to go anhead and use the stove then with either the S/P or the GenSet and there is no danger associated with the Reverse Polarity light on when operating off the GenSet?

Again, thanks for your time!

VB

Re: Electric Stove Reverse Polarity Indicator Only When Operating Off GenSet

VerBoatin said:

Hi Thalasso,

Wow, you provided an abundance of information in a very short explanaton! Well said and thank you! Based on your assessment, allow me this final question; I am safe to go anhead and use the stove then with either the S/P or the GenSet and there is no danger associated with the Reverse Polarity light on when operating off the GenSet?

Again, thanks for your time!

VB

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When on shore power the light should be green. If not better start looking for a problem.Don't use anything electrical. In fact if it's red on shore power i would disconnect it. When on the generator the shore power has to be disconnected and you should be okay

Re: Electric Stove Reverse Polarity Indicator Only When Operating Off GenSet

Hello Thalasso,
Once again thank you for your information. As you stated when I am on shore power the generator is disconnected (it is blocked on the circuit breaker panel so the generator cannot be used when shore power is being used and vice versa) and I have no reverse polarity lights whatsoever. The only time I have ever seen a reverse polarity light was when I'm operating on generator and the stove is being used on electric power. Again thank you for your information and guidance and I hope I can be of assistance to you or another member of the forum in the future. VB