My Portable Ultra Isolation (AC Power) XFMR

[Remoteness]

...And, I call this heavy weight XFMR portable? This thing weights a “ton.”
When we attach the stainless steel protective frame and wheels, it’s going to be a beast, but a very manageable beast.

About a month ago or so, we finally started to wire and build out the panels of the remaining two (out of six) Ultra Isolation transformers I bought as a lot of six many moons ago.
The other four are currently in Jethro and Elroy.

The apparatus in the pictures is completed and ready to be energized for action!
The other one shall be completed when I receive the remaining parts.

It will live in The Bread Mobile…
Its panels are designed slightly different from this one to help facilitate TBM's mounting and connector setups.

Here’s a picture of Dave (in the white area of the shop) wiring the XFMR panels.
You’ll also find some close up shots of the internal wiring.

[Remoteness]

This AC power isolation transformer happens to have three primary taps -- 208V, 240V and 480V.
I decided to only use the 208 and 240 volt taps since I’ve never came across 480 volts on any location dates.
The tap switch is a two position device

As you can see in the picture, one side of the unit has four L5-30 connectors.
They are wired to (four) individual 30 amp breakers coming off of the secondary side of the transformer.

Below the four 30 amp breakers you will find a main (two pole) 70 amp breaker wired after the Cam-Lok (16 series) input connectors and before the primary side interface terminals.

A fused analog meter is wired after the input Cam-Loks and before the main breaker so we can see the incoming voltage before we (if applicable) switch the tap or turn on the breaker.
If we need to switch the tap, we can do it without any hassle.
A neon pilot light is wired after the breaker for additional (bell & whistle factor) monitoring of the energized appliance.

We have a multipurpose digital energy, power and volts/amps/freq meter wired after the main breaker to completely measure and detect the transformer's input and output conditions.

Besides the L5-30s we also have three output Cam-Loks (ground, neutral and hot) wired directly from the secondary side interface terminals.

In the two photos below you will find a full shot of the XFMR and a close up of the panels

[Shelton]

Hey Steve,

Why only one leg on the Cam-Lock outputs? Why not a typical single phase break out?

Thanks for showing your toys!

I miss playing with all this stuff.

-Shelton

[Remoteness]

Originally Posted by Shelton

Hey Steve,

Why only one leg on the Cam-Lock outputs? Why not a typical single phase break out?

Thanks for showing your toys!

I miss playing with all this stuff.

-Shelton

Well, the transformer can handle single phase a 208, 240 or 480 volt input with either a 120 or 240 volt output.
My choice was to go with the 120 volt option.
Everything I got is 120 volts so, there was no need or reason to have 240 volts available.

[Shelton]

Right,

But if you had a single phase cam lock output you could have two 120V legs worth of power to play with.

Or did you wire the twist-locks to one leg and the Cams to the other?



Your tranny does give you two hots on the secondary right?

[Remoteness]

Yes, but I do not need two legs of 120 volts to play with.

The twist-locks and Cam-Loks are wired to the 120 volt terminals only.

[Remoteness]

Here's a diagram of the input / output options.

[Shelton]

But I thought you were all about options!

Looks to me like you are wasting half of the available amperage on that iso tranny.

On the secondary side, you have 120V available between X1 and X2. You also have another leg from X2 and X3.

Seems to me if you were building this as a stand alone apliance that's not tied to a particular vehicle and might be available as a rental item, that making the other leg available on the Cam-Lock outputs would make this a more adaptable and rentable item.

All of the iso tranny's I've rented always had single phase camlocks on the secondary.

[Remoteness]

I am all about options!

I'm not wasting anything.

Dave Wilkerson and I talked about the same thing because we were going to wire it exactly like you said, but when I talked to the manufacturer they said we should not use it that way. X1 & X3 is for 240 volts and X1 & X2 is for 120 volts. So, even though you may think we have an additional 120V leg (referenced to neutral) available between X2 and X3 the manufacturer does not recommended it to be used. The copper wire used for X3 is even smaller in diameter than X1 & X2. Go figure?

In any event, this item is rentalable and available to my close friends and associates.
With that said, this XFMR has already been rented out on a number of sessions way before we modified it.
Lucky for me I'm not a rental house. I get to choose whom I want to do business with on that front.

YMMV!

[Shelton]

Ok, cool.

Strange that they would build it that way.

Lucky that you keep your rentals to a close circle, I was a rental manager for a production house out here in So Cal for years.

I just wanted to make sure you thought of all the options. Should've known better than to think you didn't!


-Shelton

[Remoteness]

Yeah, I hear you!

I questioned the fact that the diagram above does not have a "< --- 120 V --->" between X2 & X3 and then we were set straight.

It IS pretty strange indeed, but...

You can do 120/240 split loads as long as the current from X3 does not exceed the 240 Vac output current that's specified for this transformer or the combined load Volt-Amps) supplied by X1 & X3 doesn't exceed the transformer's power rating.

The 120 Vac load must connect between X1 & X2 and the 240 Vac load must connect between X1 & X3.

I insist on keeping my outside rentals within my close circle. Everytime we went outside this circle I got burned. Even sub-rentals to some of the "big" rental houses proved to be a disaster. Outsiders don't give a freak about your stuff like friends and close associates do.

My gear is in very good condition and I want to keep it that way.
IMO it's not worth the (small) rental money to change that situation.

The funny thing is, I treat rental gear like it's my own stuff. Too bad I don't get an additional discount because of it.

[RedEar]

I saw this beute last week and it is gona be nice for these guys... Real big though.

[Shelton]

I wish everyone treated gear like that!

So how many amps do you get out of that thing anyway?

[Steve Smith]

Originally Posted by Remoteness

A fused analog meter is wired after the input Cam-Loks and before the main breaker so we can see the incoming voltage before we (if applicable) switch the tap or turn on the breaker.

That is the balls my friend...

[Remoteness]

Originally Posted by Steve Smith

That is the balls my friend...

Yeah, why bother grabing your multimeter if a meter is already built in...

Elroy's power panel will also have single banana plugs installed for the ground and hot leg Cam-Loks so you can test the analog meter when applicable.

A pilot light will also be mounted about each hot leg to show that Elroy's energized,

[RedEar]

Elroy is gona be amazing.