garmstro55
Senior Member
Thanks to Red Pearl (https://sway.office.com/F0aSm8VOnaj0iz58?ref=Link) I identified and solved my problem with low supply voltage at my home marina.
With my new (to me) MS400 I was seeing only about 100 volts on the panel meter when on shore power and almost 120 volts when running the generator. This made me go hmmm, but I had no idea what was going on.
According to the detailed report on the Red Pearl site, it has to do with the way the marina is wired, coupled with the 50 amp 240 volt boat power inlet design of the Mainships.
This concerned me as some equipment and appliances don't like low voltage supply. I encourage anyone with a MS who has this issue to carefully read the explanation and solution posted by Red Pearl.
In a nutshell as I understand it, my marina is wired with 208 split phase service at the pedestals. This isn't a problem for the 30 amp, 120 boats as you can get 120 from this design. BUT, the MS is getting only 208 and it is fed to the isolation transformer, where it gets cut it in half. I was seeing something like 101 or 102 volts. Not good.
As it turns out, the Charles isolation transformer has a "boost" feature that will give you 120 volts or so with the 208 V coming in. You just need to add a couple of switches as explained in the writeup.
I just had my electrician finish the job last week and yippee, I am now getting close to 120 to my panel with the transformer in boost mode.
I added a label to the panel to remind me to switch to "un-boosted" when traveling to other marinas until I find out what voltage the transient marina is providing.
The transformer is behind the panel in the back of the guest stateroom closet. Here's a shot of the transformer and also the switch installation.
I am surprised I have not seen anyone on this forum complain of this problem before. I think my stove, oven and summer kitchen grill will now work better and the fridge and AC might last longer now that they are getting the correct voltage.
One more thing to mention, I had Blue Sea add the led's and labels, but they don't actually work because of the way it must be wired. I have to add my own labels to keep it straight.
With my new (to me) MS400 I was seeing only about 100 volts on the panel meter when on shore power and almost 120 volts when running the generator. This made me go hmmm, but I had no idea what was going on.
According to the detailed report on the Red Pearl site, it has to do with the way the marina is wired, coupled with the 50 amp 240 volt boat power inlet design of the Mainships.
This concerned me as some equipment and appliances don't like low voltage supply. I encourage anyone with a MS who has this issue to carefully read the explanation and solution posted by Red Pearl.
In a nutshell as I understand it, my marina is wired with 208 split phase service at the pedestals. This isn't a problem for the 30 amp, 120 boats as you can get 120 from this design. BUT, the MS is getting only 208 and it is fed to the isolation transformer, where it gets cut it in half. I was seeing something like 101 or 102 volts. Not good.
As it turns out, the Charles isolation transformer has a "boost" feature that will give you 120 volts or so with the 208 V coming in. You just need to add a couple of switches as explained in the writeup.
I just had my electrician finish the job last week and yippee, I am now getting close to 120 to my panel with the transformer in boost mode.
I added a label to the panel to remind me to switch to "un-boosted" when traveling to other marinas until I find out what voltage the transient marina is providing.
The transformer is behind the panel in the back of the guest stateroom closet. Here's a shot of the transformer and also the switch installation.
I am surprised I have not seen anyone on this forum complain of this problem before. I think my stove, oven and summer kitchen grill will now work better and the fridge and AC might last longer now that they are getting the correct voltage.
One more thing to mention, I had Blue Sea add the led's and labels, but they don't actually work because of the way it must be wired. I have to add my own labels to keep it straight.
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