220v to 110v splitter (in Mexico)

[jordanbigel]

So, my boat uses US 120v/60h/30a power and I find myself in a marina (Ensenada) with a slip that has 220v/60h/50a power.

I saw another boat with a Y-Adapter which was connected to the 220v outlet and then 2 120v/30a cables went into his boat.

So I'm thinking all I need is one of those Y-Adapters which will convert the 220v/50a into 2 110v/25a legs, which I can then connect one of them to my existing shore power cables and leave the other empty (or with a plastic bag wrapped around it)?

Now, I asked the marina's staff about this, 3 of them, and only 1 of them spoke any English - but they seemed to agree emphatically that this is a workable plan (if I can get the Y-Adapter).

Is this right?
https://www.westmarine.com/marinco-e...-12998423.html

It says in the copy:
This “Y” adapter splits a single 50A 125V/250V shore power service into two 30A applications.


So this all sounds right to me, but the part which leaves me slightly unclear is where it says "125v/250v" - is 220v considered the same thing as 250v the way 110v and 125v is considered the "same" in the US (I am not really clear on WHY they are the same, I mean, can't they pick one? Shrug.)

THANK YOU!

[donradcliffe]

I was in Baja Naval last week, and the docks had 30 amp sockets, that looked like they would fit my normal 30 amp plug, but did not. I figured that they were playing the marina game where you had to rent their adaptor to get dock power. Since we were only staying long enough to check out of Mexico, I didn't bother to solve the problem

I have used a 50 amp splitter in the past, but be very careful. There are more than one configuration of 250v/50 amp plug, and they don't play nice--there is no standard. If you buy a splitter, make sure you can return it if it doesn't fit.

The good news is that the dock power is probably US compatible, with a neutral and 2 20v hot wires that are out of phase. You should be able to get 120v across two wires, which is not the case in most of the world, but those guys have entirely different looking sockets.

If you are the adventuresome type, cut your plug off, strip the wires, and stuff two of them in the right socket holes, and wrap some electrical tape around to keep things in place. I've seen it done.

[jordanbigel]

Originally Posted by donradcliffe

I was in Baja Naval last week, and the docks had 30 amp sockets, that looked like they would fit my normal 30 amp plug, but did not. I figured that they were playing the marina game where you had to rent their adaptor to get dock power. Since we were only staying long enough to check out of Mexico, I didn't bother to solve the problem

I have used a 50 amp splitter in the past, but be very careful. There are more than one configuration of 250v/50 amp plug, and they don't play nice--there is no standard. If you buy a splitter, make sure you can return it if it doesn't fit.

The good news is that the dock power is probably US compatible, with a neutral and 2 20v hot wires that are out of phase. You should be able to get 120v across two wires, which is not the case in most of the world, but those guys have entirely different looking sockets.

If you are the adventuresome type, cut your plug off, strip the wires, and stuff two of them in the right socket holes, and wrap some electrical tape around to keep things in place. I've seen it done.

I am not adventuresome, in that way... Zzzzaaaaappppp.

[Capt.Don]

Are you sure there's not a 110v 30a circuit on the dock? All of the marinas throughout the sea and mainland I've visited have both. I've never needed to use the variuos 30a/50a converters.

[jordanbigel]

Originally Posted by Capt.Don

Are you sure there's not a 110v 30a circuit on the dock? All of the marinas throughout the sea and mainland I've visited have both. I've never needed to use the variuos 30a/50a converters.

There are, in other slips, one of which is available. However, it is a less desirable location, and we plan to be here for several months.

[sv_pelagia]

Originally Posted by jordanbigel

There are, in other slips, one of which is available. However, it is a less desirable location, and we plan to be here for several months.

Which marina? Cruiseport we only saw 120v. Same also for other west coast Mexico marinas.

[jordanbigel]

Originally Posted by sv_pelagia

Which marina? Cruiseport we only saw 120v. Same also for other west coast Mexico marinas.

Yes, Cruiseport. F-Dock. The 220v power boxes have big red stickers on them saying 220v/50a - hard to miss. I have not walked the other docks, perhaps only on F dock.

[HeywoodJ]

Mexico largely uses the same electrical standards as the US, and Baja even more so. What you would have in a 220/240V, 50A, split-phase system is two 110/120V legs, each capable of delivering 50A, and out of phase with each other such that between the two hot legs you have 220/240V. A neutral leg in the middle of the two hot legs is standard in the split-phase system.

In theory, you connect to one hot leg, the neutral, and the grounding conductor and you have a single 110/120V, 50A connection (not 25A). As mentioned up thread, the difficulty is in the connectors. The link in the OP is to a plug that has three pins; two phases and the neutral. The grounding conductor connection is provided by the shell. There are other split-phase 50A connectors that will have 4 pins; one pin for each phase, one pin for the neutral, and one pin for the grounded conductor.

Take a look at the pedestal connections. Do they have holes for four pins? In that case you need a different splitter. Do they have holes for three pins, and a metal sleeve around the whole thing where the plug gets inserted? In that case there is a >90% chance that the linked splitter will work. There is a small risk that you'll get a real oddball connector, but it generally comes down to 3 or 4 pins.

One other thing, the "standard" in Mexico is 3-phase power, and when 220V is supplied it is usually two legs of a three-phase system and it is usually 127V phase-neutral and 220V phase-phase. There's a lot of variation in that "standard", so take it with a grain of salt. The one other small thing to confirm is that the dock is not supplying 3-phase power with no neutral, but that would be very unusual as well. A voltmeter used at the pedestal will tell you quickly.

Here's a 3-pin with metal shell:


And a 3-pin with a central ground pin (didn't discuss this one above, usually Euro):


And here's a 4-pin for reference, this is a 30A, couldn't dredge up a 50A quickly on the internet, but they do exist because I've plugged in to them:

[smac999]

There is no need to buy a y if you only have 1 Inlet. Just buy a single adapter. It will be cheaper.

https://www.marinco.com/en/p/121A/Pi...5-250V-Male-To

[smac999]

Originally Posted by HeywoodJ

One other thing, the "standard" in Mexico is 3-phase power, and when 220V is supplied it is usually two legs of a three-phase system and it is usually 127V phase-neutral and 220V phase-phase

Lots of 3 phase wired marinas in western Canada but it’s only 208v. 120 l-n. Only 200v by the time it gets down the dock. Air con motors really don’t like it. Luckly don’t need much ac up here.

[jordanbigel]

Originally Posted by smac999

There is no need to buy a y if you only have 1 Inlet. Just buy a single adapter. It will be cheaper.

https://www.marinco.com/en/p/121A/Pi...5-250V-Male-To

This looks perfect!

Plus, I found the non-EEL version for $83 on Amazon - West Marine does stock this same adapter, but in the EEL version, and it's freaking $169! The Y Adapter would have cost me even more.

Huge thanks to you Smac!

[jordanbigel]

Originally Posted by HeywoodJ

Mexico largely uses the same electrical standards as the US, and Baja even more so. What you would have in a 220/240V, 50A, split-phase system is two 110/120V legs, each capable of delivering 50A, and out of phase with each other such that between the two hot legs you have 220/240V. A neutral leg in the middle of the two hot legs is standard in the split-phase system.

In theory, you connect to one hot leg, the neutral, and the grounding conductor and you have a single 110/120V, 50A connection (not 25A). As mentioned up thread, the difficulty is in the connectors. The link in the OP is to a plug that has three pins; two phases and the neutral. The grounding conductor connection is provided by the shell. There are other split-phase 50A connectors that will have 4 pins; one pin for each phase, one pin for the neutral, and one pin for the grounded conductor.

Take a look at the pedestal connections. Do they have holes for four pins? In that case you need a different splitter. Do they have holes for three pins, and a metal sleeve around the whole thing where the plug gets inserted? In that case there is a >90% chance that the linked splitter will work. There is a small risk that you'll get a real oddball connector, but it generally comes down to 3 or 4 pins.

One other thing, the "standard" in Mexico is 3-phase power, and when 220V is supplied it is usually two legs of a three-phase system and it is usually 127V phase-neutral and 220V phase-phase. There's a lot of variation in that "standard", so take it with a grain of salt. The one other small thing to confirm is that the dock is not supplying 3-phase power with no neutral, but that would be very unusual as well. A voltmeter used at the pedestal will tell you quickly.

Thanks for the details Haywood! I have verified its the 3 pin 220/250v connector, with 1 straight blade and 2 blades having the outward pointing notch. Same as this guy:

https://www.amazon.com/dp/B000NI58ZQ

[HeywoodJ]

Then you should be good to go. Me being the #$$# retentive type, I would grab a voltmeter and check between the pin with the notch and the one without, you should have 127V (or thereabouts). Notch to notch would be the 220V.

One very small caveat in all of this, the shore pedestal breaker will be 50A, your own shore power cord will be rated at 30A. Once it gets to the boat presumably you have a 30A main breaker very close to where you connect on the boat. But the shore power cord between pedestal and boat will only be protected by the 50A breaker. Since you will be there a while, pay close attention to the shore power cord for damage.

For a longer stay I would consider either asking the marina to swap in a 30A breaker (about a 10 minute job but usually requires some sweet talk), or going to the local construction supply places (there are a couple in Ensenada) and seeing if they have a 50A "job box". These are used to split this kind of service on construction sites and have smaller breakers built in. Cost in the States is way more than the simple pigtail, don't know about in Mexico.

[jordanbigel]

Originally Posted by HeywoodJ

One very small caveat in all of this, the shore pedestal breaker will be 50A, your own shore power cord will be rated at 30A. Once it gets to the boat presumably you have a 30A main breaker very close to where you connect on the boat. But the shore power cord between pedestal and boat will only be protected by the 50A breaker. Since you will be there a while, pay close attention to the shore power cord for damage.

Yes, I did realize this.

I have my Victron Multiplus set to limit AC input to 21amps due the past experience blowing the 30mp breaker and melting the shore power cable connectors! After reading Mainsail about how poor these connectors are, I noted he suggests a 30% derating of current to prevent overheating and melting, which is how I got to 21amp current limit on the Victron.

My assumption is that as long as I keep current down in this way, I should not be at any (additional) risk.