Transformer Bypass

[Bugsy]

I am at a marina with 208 V on the 50 amp shorepower.
My boat is a 1981 Conv. with a transformer.

It was suggested by the dockmaster that some Hatteras boats have a switch to enable you to bypass the transformer and take the "raw" power from the dock.

I would avoid or minimize the negative results of the voltage drop---dim lights; lower microwave power.

Does anyone know whether the 1981 43 ft. convertibles boat were equipped with such a switch---and, if so--its location?

 

[Canuck Dennis]

I would think that even if you could bypass you would be no further ahead, 208 v gives you 104 on ea leg, what you hope for is a 5% tap to get it up to 110 ea leg,

 

[SKYCHENEY]

Bypassing would give you 120v on any one hot leg to neutral. I would, however, advise against doing that. A much better alternative is to keep your protection against stray current and inverse polarity by installing a boost switch. The transformers are capable of boosting that power by about 15% with a simple switch that runs the current off of different taps on the transformer. I added the switches to my boat last year and I think it's one of the best upgrades I've done.

 

[tonytrakovich]

I had an issue in the Bahamas with low voltage as well. The boat hates it. As voltage decreases, current increases. Air conditioning compressors hate it most and start running hot. Fluorescent lights act like you have bad ballasts and don't turn on properly.

I contacted Hatteras and a very helpful electrical guy (don't remember name) and he sent me the wiring diagrams of the transformers. My transformers had multiple taps for adjusting voltage. He had a diagram for installing a switch to use the taps and change voltage. It is important not to permanently wire the transformers in the boost configuration. You don't want an over voltage condition when you are at a marina with 240 volts. I will look for my diagrams and post if I can find them.

 

[JoseSuarez]

Sky Cheney

It is just a coincidence I had a very similar problem. I encountered some battery charging problems recently and it turned out I was only getting 204 from the dock box. I checked with the marina and they have corrected the problem. We are getting 210.

I've heard low voltage is a common marina problem. I've considered installing a Voltage Booster or a Voltage regulator but, if I can get by with just a simple switch that will be great.

Can you provide info on the type of switch and model that worked for you. We run several high
power appliances when we are in the slip.

Thank you so much.

Cheers,
Jose
MV "PILAR"
79 Hatteras 60
San Diego, CA

 

[Bugsy]

The switch to "booster" is probably what the marina meant rather than a "bypass".

I would very much appreciate a diagram or other more detailed explanation as to the way to wire in this voltage enhancer.

Thx

 

[bobk]

The switch to "booster" is probably what the marina meant rather than a "bypass".

I would very much appreciate a diagram or other more detailed explanation as to the way to wire in this voltage enhancer.

Thx

Me too, and costs if possible. There seem to be a lot of marinas that don't give a rats a$$ about their power problems.

Bobk

 

[Boatnut]

I am at a marina with 208 V on the 50 amp shorepower.
My boat is a 1981 Conv. with a transformer.

It was suggested by the dockmaster that some Hatteras boats have a switch to enable you to bypass the transformer and take the "raw" power from the dock.

I would avoid or minimize the negative results of the voltage drop---dim lights; lower microwave power.

Does anyone know whether the 1981 43 ft. convertibles boat were equipped with such a switch---and, if so--its location?

Noting what Sky said, a switch is the way to go. But in my case being as forgetfull as I am, I installed a relays setup, to automatically turn off the boost mode, as our marina is somehwere between 215 and 230. Typical great Florida Power. Or is it Duke I can't keep up.

 

[Boatnut]

I would think that even if you could bypass you would be no further ahead, 208 v gives you 104 on ea leg, what you hope for is a 5% tap to get it up to 110 ea leg,

Dennis, what you are saying may be correct if the incomming power is supposed to be 220/240 volts. A 208 system, which many marinas have will give you 120 volts. A good explaination I found on the internet, follows.

The 120/208YVAC system describes the output of a 3 phase transformer, used mostly in commercial applications.

The output phase to phase is 208 volts.

The 3-phase output also provides three 12OVAC lines with voltages signals being 120 degree apart from each other, The 120 volts is produce between Line-to-Neutral.

This type of connection is referred as a WYE configuration.

 

[chuckbullett@gmail.com]

Dennis, what you are saying may be correct if the incomming power is supposed to be 220/240 volts. A 208 system, which many marinas have will give you 120 volts. A good explaination I found on the internet, follows.

The 120/208YVAC system describes the output of a 3 phase transformer, used mostly in commercial applications.

The output phase to phase is 208 volts.

The 3-phase output also provides three 12OVAC lines with voltages signals being 120 degree apart from each other, The 120 volts is produce between Line-to-Neutral.

This type of connection is referred as a WYE configuration.

Boatnut is correct. This 120/208 configuration allows the marina to balance the power to all three poles in the distribution box and there-by power balancing between slip service risers--- but a downfall besides the low voltage situation you're dealing with is that it isn't very resilient to lightening. A Delta 220/240 is more robust in this regard, but can kill you, too. Very expensive to install.

IMHO it is the responsibility of the owner of a vessel to provide for themselves... self reliance is important as a yachtsman. Install a PAIR of buck boost transformers, and you'll also benefit from being isolated from stray ground currents, possibly burning up prop shafts and propellers, and you'll be ready to go anywhere.

I would also recommend employing a certified ABYC electrician for the job. Protect yourself, your crew, and most importantly, preserve the integrity of your insurance policy and the resale value of your yacht.

Just my two cents as a professional broadcast engineer (CBS) with 30 years of experience in big power stuff. Be careful please.

Chuck B.; 1978 53MY m/v Chartmaker; San Francisco & 1978 Aries-32 s/vThe Chester P

 

[Boatsb]

Boatnut is correct. This 120/208 configuration allows the marina to balance the power to all three poles in the distribution box and there-by power balancing between slip service risers--- but a downfall besides the low voltage situation you're dealing with is that it isn't very resilient to lightening. A Delta 220/240 is more robust in this regard, but can kill you, too. Very expensive to install.

IMHO it is the responsibility of the owner of a vessel to provide for themselves... self reliance is important as a yachtsman. Install a PAIR of buck boost transformers, and you'll also benefit from being isolated from stray ground currents, possibly burning up prop shafts and propellers, and you'll be ready to go anywhere.

I would also recommend employing a certified ABYC electrician for the job. Protect yourself, your crew, and most importantly, preserve the integrity of your insurance policy and the resale value of your yacht.

Just my two cents as a professional broadcast engineer (CBS) with 30 years of experience in big power stuff. Be careful please.

Chuck B.; 1978 53MY m/v Chartmaker; San Francisco & 1978 Aries-32 s/vThe Chester P

Craig didn't take Into account that many marinas have 240 v systems with voltage drop. It's not supposed to be 208. It's degraded to 208. The farther out on the dock the worse it gets at many places.

 

[TommyB]

Bypassing would give you 120v on any one hot leg to neutral. I would, however, advise against doing that. A much better alternative is to keep your protection against stray current and inverse polarity by installing a boost switch. The transformers are capable of boosting that power by about 15% with a simple switch that runs the current off of different taps on the transformer. I added the switches to my boat last year and I think it's one of the best upgrades I've done.

any diagrams or instructions on doing this / having it done.
part list etc
thanks in advance

 

[SKYCHENEY]

Boatnut is correct. This 120/208 configuration allows the marina to balance the power to all three poles in the distribution box and there-by power balancing between slip service risers--- but a downfall besides the low voltage situation you're dealing with is that it isn't very resilient to lightening. A Delta 220/240 is more robust in this regard, but can kill you, too. Very expensive to install.

IMHO it is the responsibility of the owner of a vessel to provide for themselves... self reliance is important as a yachtsman. Install a PAIR of buck boost transformers, and you'll also benefit from being isolated from stray ground currents, possibly burning up prop shafts and propellers, and you'll be ready to go anywhere.

I would also recommend employing a certified ABYC electrician for the job. Protect yourself, your crew, and most importantly, preserve the integrity of your insurance policy and the resale value of your yacht.

Just my two cents as a professional broadcast engineer (CBS) with 30 years of experience in big power stuff. Be careful please.

Chuck B.; 1978 53MY m/v Chartmaker; San Francisco & 1978 Aries-32 s/vThe Chester P

If he already has the OEM isolation transformers, there is no need to buy new boost transformers as the current ones can be rewired to perform the same function. I'm not a CBS, but I've rewired several of these and I use the boost function on mine several times per season.