A/c transformer mod

[saltshaker]

Does anyone have detailed info for modifying the line transformers to work as boost transformers? I know there's a mod to add switches for boost

[sandspur1966]

Hey Jack-

I had Hatteras send me the wiring mod diagram for my OEM transformer. I think they called it the European setup or something. I installed a switch to alternate back and forth at the main panel so I can go back to OEM depending on whether or not the dock I'm on has a transformer or is just running two hot legs off of their street drop.

Was pretty easy, I can try and track it down and scan it to your email... suppose it depends on if we have the same transformer make and model though.

Shawn

[Boatnut]

Jack if you have a print of the line transformer wiring, I can send you a drawing on how to do it. As stated it is pretty simple.

[SKYCHENEY]

Just did mine this weekend. You actually have to reverse the windings. Hatteras has the X side as the input and the H side as the output. The output side has 6 taps while the input has only 4.

Here is the deal: You will need a switch to either connect H3 and H4 together or H2 and H5 together. You will also need to make the H side the input side and the X side as the output.

With H3 and H4 tied together, you will get standard line voltage out of X1 and X4. With H2 and H5 tied together, you will get boost out of X1 and X4. This is while inputting your power from the dock through H1 and H6.

If you need more info, just call me Jack.

[fissioneng]

You actually have to reverse the windings. Hatteras has the X side as the input and the H side as the output.

Sky,

Any clue why Hatteras did this? Mine's the same way. Maybe a Roger question?

[saltshaker]

Spoke to Hatteras this AM. I'm trying to get a schematic of the transformers. Apparently they used a few different units and it can vary from year and model. Sky do you have any wiring diagrams of your transformers and are they the Jefferson 15KVA units? That's what I believe mine are but there aren't any tags on them. They're a blue/grey with a red warning label on the top. I'm waiting for Hatteras to confirm that's what I have. Hatteras did say the transformer ins/outs need to be reversed from the OEM set up.

[fissioneng]

Spoke to Hatteras this AM. I'm trying to get a schematic of the transformers. Apparently they used a few different units and it can vary from year and model. Sky do you have any wiring diagrams of your transformers and are they the Jefferson 15KVA units? That's what I believe mine are but there aren't any tags on them. They're a blue/grey with a red warning label on the top. I'm waiting for Hatteras to confirm that's what I have. Hatteras did say the transformer ins/outs need to be reversed from the OEM set up.

I got a drawing faxed to me from Jefferson Electric back in 2007. They custom made these for Hatteras. Mine is a 15 KVA, catalog number 211-0001-078. You could call them or I could pdf what I have and email it to you.

My guess is that the reversing allows you to plug into 120 and output 240. At least that's what my owner's manual says. If you flip it around maybe you lose this feature?

[saltshaker]

I got a drawing faxed to me from Jefferson Electric back in 2007. They custom made these for Hatteras. Mine is a 15 KVA, catalog number 211-0001-078. You could call them or I could pdf what I have and email it to you.

My guess is that the reversing allows you to plug into 120 and output 240. At least that's what my owner's manual says. If you flip it around maybe you lose this feature?

Thanks. I have a call in to Jefferson and am waiting for a reply. If they cant help me I would like a copy of what you have.

[SKYCHENEY]

Spoke to Hatteras this AM. I'm trying to get a schematic of the transformers. Apparently they used a few different units and it can vary from year and model. Sky do you have any wiring diagrams of your transformers and are they the Jefferson 15KVA units? That's what I believe mine are but there aren't any tags on them. They're a blue/grey with a red warning label on the top. I'm waiting for Hatteras to confirm that's what I have. Hatteras did say the transformer ins/outs need to be reversed from the OEM set up.

I have the Jefferson units. I don't have any schematics other than what is inside the cover of the transformer.

[SKYCHENEY]

Thanks. I have a call in to Jefferson and am waiting for a reply. If they cant help me I would like a copy of what you have.

Getting 120v in and 240v out is not a function of reversing the transformer. That schematic is on the inside cover of the transformer.

If you want to boost 208v to 240v, you DO have to reverse the input and output. On the schematic it shows how to get "216v output from 240v input". This is why you need to reverse the input and output leads. Then you need to tie H2 and H5 together (boost) instead of H3 and H4(no boost). That is all the switch does. It's actually pretty simple.

I bought a voltage meter to mount near the switch as well since the one on the main panel only shows the input voltage and I want to know what is actually coming out of the transformer.